JP3914908B2 - Vacuum insulation - Google Patents

Description

The present invention relates to a vacuum heat insulating material.

  A vacuum heat insulating material is known which is configured by covering a core material made of a heat insulating material with a jacket material and sealing the inside under reduced pressure.

  Japanese Patent Application Laid-Open No. H10-228561 discloses a material in which the outer cover material is composed of a surface protective film, a metal layer, and an inner layer film, and the inner layer film is 50 μm or more and 150 μm or less. This inner layer film is made of a heat-weldable resin, and the thermal conductivity varies depending on the thickness. Therefore, the thickness is such that the thermal conductivity does not affect the heat insulation performance of the vacuum heat insulating material, that is, 50 μm to 150 μm. It is supposed to be.

  On the other hand, Patent Document 2 discloses a vacuum heat insulating material in which a front-side film and a back-side film of a jacket material are joined at a peripheral portion of a core material, and an aluminum foil and a back-side of the front-side film in the joined portion The thing which defined the separation distance of the aluminum foil of a film is disclosed. The above-mentioned separation distance is determined in consideration of the gas barrier property of the jacket material and the thermal insulation between the front surface side film and the rear surface side film.

JP-A-8-303685

Japanese Patent Laid-Open No. 10-185417

  In the above prior art, problems due to the surface property of the vacuum heat insulating material and prevention of damage to the outer cover material by the core material at the time of manufacturing the vacuum heat insulating material have not been considered. In particular, when a core material made of an inorganic fiber material is used, there is a problem in surface properties as compared with the case where a hard urethane foam is used for the core material. The following problems arise when a core material made of an inorganic fiber material is incorporated into a jacket material. Hereinafter, this problem will be described with reference to FIGS.

FIG. 6 shows an enlarged cross-sectional view of the core material. On the surface 31a of the core material 31, material particles 31b, foreign matter 31c, or ridges 31d having large diameters or grains among the materials constituting the core material are generated, and the material particles 31b, foreign matter 31c, or ridges 31d are T ₁ from the surface 31a. In order to project only the dimension, T ₂ dimension or T ₃ dimension, the outer jacket material is damaged, and the gas permeation amount increases from the damaged part after a long period of time, but the prevention measures have not been considered. .

  FIG. 7 is an assembled perspective view of the core material and the jacket material. As shown in FIG. 7, when the core material 31 is inserted into the jacket material 32 whose three sides are heat-welded, if there is fine waste 36 that falls from the core material at the entrance of the jacket material, When the material is sealed under reduced pressure after the material is inserted, the fine debris 36 adheres to the heat welding portion 32a. At this time, the gas permeation amount of the heat welding part 32a increases.

That is, as shown in FIG. 8, when the fine debris 36 dropped from the core material is sandwiched between the heat-welded portions of the jacket material, the seal size of the heat-welded portion is smaller than a predetermined size and becomes T _10. When the period elapses, the amount of gas permeation increases from this clamping part. In the above prior art, these preventive measures have not been taken into consideration.

  From the above, the present invention provides a refrigerator that employs a vacuum heat insulating material that can maintain excellent heat insulating performance over a long period of time even if raw material grains or the like are generated on the surface of a core material made of an inorganic fiber material. The purpose is to provide. Moreover, it aims at providing the structure of the vacuum heat insulating material by which fine waste etc. are not clamped by the heat welding part of a jacket material, and a refrigerator using the same.

In order to achieve the above object, the present invention is a vacuum heat insulating material in which a core material composed of inorganic fibers is covered with a jacket material having gas barrier properties, and the inside is decompressed,
As the core material, a laminate of a plurality of artificial mineral fiber heat insulating materials is used,
The jacket material includes a surface protection film that protects the surface, a gas barrier layer that is formed of a metal that is located on the inner side of the surface protection film, and that is located on the inner side of the gas barrier layer and seals the inside of the jacket material. An inner layer film that can be welded as much as possible,
An organic material layer that covers the inner surface of the inner layer film and compresses the core material is interposed between the jacket material and the core material, and the total thickness of the inner layer film and the organic material layer 40
It is characterized by being μm or more.
In the vacuum heat insulating material, the organic material layer has a thickness that maintains the gas barrier property of the gas barrier layer even when locally compressed and deformed .

Moreover, in the vacuum heat insulating material in which an organic material layer covering the core material is interposed between the jacket material and the core material,
The organic material layer is an organic material layer that covers the core material separately from the jacket material. Furthermore, in any of the above-described configurations, a polyethylene terephthalate resin having a thickness of 20 μm or more is used as the organic material layer.

According to the present invention, it is possible to provide a vacuum insulation material capable of maintaining the excellent thermal insulation performance over a long period.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a refrigerator showing an embodiment of the present invention.
As shown in FIG. 1, the refrigerator box 1 includes an outer box 2 and an inner box 4, and a foam heat insulating material 3 such as urethane filled between the outer box 2 and the inner box 4. The refrigerator box 1 has a refrigerator compartment (vegetable compartment) 5, an ice making compartment (select compartment) 6 and a freezer compartment 7 formed therein. 8 is a cooler that cools the refrigerator compartment (vegetable compartment) 5 to a predetermined temperature, and 9 is a cooler that cools the ice making chamber (select chamber) 6 and the freezer compartment 7 to a predetermined temperature. The coolers 8 and 9 evaporate the refrigerant circulated in the compressor 10 and are maintained at a relatively low temperature in the refrigerator in order to maintain a predetermined low temperature. Therefore, from the viewpoint of energy saving of the refrigerator, the vacuum heat insulating material having a lower thermal conductivity than the foamed heat insulating material 3 such as urethane is contained in the foamed heat insulating material 3 on the rear projection surface of the coolers 8 and 9 having relatively large heat leakage in the refrigerator. 11 is arranged.

  FIG. 2 is a schematic cross-sectional view of a vacuum heat insulating material showing an embodiment of the present invention. As shown in FIG. 2, the vacuum heat insulating material 11 is provided with a core material 17 in an interior covered with a gas barrier outer material 20, and the inside of the outer material 20 and the core material 17 is depressurized to a predetermined degree of vacuum. Thus, it is configured to have heat insulation performance as vacuum insulation. The outer cover material 20 has a surface protective film 12 formed of nylon resin, polyethylene terephthalate resin, or the like on the outer surface, and has a metal foil 15 such as aluminum with good gas barrier properties on the inner side, and further on the inner side. A heat-weldable inner layer film 16 such as a high-density polyethylene resin or polyacrylonitrile resin is integrally formed. That is, the surface protection film 12 is formed of a strong nylon resin or polyethylene terephthalate resin to protect the surface of the jacket material 20, and the metal foil 15 is a gas barrier for maintaining the degree of vacuum inside the jacket material 20. The inner layer film 16 is formed as a heat-welded layer that can be heat-welded to seal the inside of the outer cover material 20, such as high-density polyethylene resin or polyacrylonitrile resin. Formed by.

  In the present embodiment, a gas barrier with strength is provided by interposing a metal deposition film 13 in which a metal such as aluminum is deposited on a support layer 14 such as polyethylene terephthalate resin or polypropylene resin between the surface protection film 12 and the metal foil 15. The property is better.

FIG. 3 is an enlarged schematic cross-sectional view of a vacuum heat insulating material showing an embodiment of the present invention. As shown in FIG. 3, the thickness T ₆ of the inner layer film 16 is combined with the thickness T _{5 of} the organic material layer film or organic material layer coating described later to form material grains, foreign matters, or wrinkles ( This material grain, foreign material, or wrinkle is represented as a material grain in the following description), etc., and the like is set to dimensions that do not damage the metal foil 15 such as aluminum having good gas barrier properties. In other words, the maximum projecting distance of the material particles such as 17f, which appear on the surface 17a of the core 17 as shown in FIG. 3 When T _4, the metal foil 15a of the protruding portion corresponding position of said workpiece grains etc. deform locally However, the thickness T ₆ of the inner layer film 16 and the organic material layer film or organic material layer coating so that the elongation rate of the locally deformed portion 15a falls within the allowable range of the tensile elongation rate of the metal foil 15 itself. It is set the total thickness T ₇ of the thickness T ₅ of the.

In other words, the material particles 17f appearing on the surface of the core material are locally compressed and deformed by the atmospheric pressure or the pressurizing pressure at the time of manufacture, and then the inner layer film 16 is further deformed. be locally compressed and deformed, so as not to impair the gas barrier properties of the metal foil 15, it is set a total thickness T ₇ of the thickness T ₅ and thickness T _6.

Note that according to our experiments, as described below, it never long term also impair the gas barrier properties of the metal foil 15 has been found if the total thickness T ₇ 40 [mu] m or more.

18 in Figure 2 is an organic material layer film or an organic material layer coating covering the surface of the core 17, the thickness thereof is set such that T ₅ described above.

  In the case where the organic material layer 18 on the core material side is an organic material layer film, an artificial mineral fiber heat insulating material impregnated with a binder as a raw material of the core material at the time of manufacturing the core material 17 described later as shown in FIG. Is not required to be released from the mold used for heat compression.

  Further, by covering the surface of the core material 17 with the organic material layer film or the organic material layer coating in this way, the core material 17 can be used when the core material is incorporated into the jacket material as shown in FIGS. It is possible to prevent the fine dust 36 from dropping from falling and to prevent an increase in the amount of gas permeation.

FIG. 5 shows an example in which the inner surface of the inner layer film 16 of the outer cover material 20 is covered with an organic material layer film or an organic material layer coating. 19 is an organic material layer film or an organic material layer coating covers the inner surface of the inner layer film 16 of the enveloping member, the thickness T ₅ is is set as described above.

  Here, an example of manufacturing the core material 17 will be described with reference to FIG. FIG. 4 is a manufacturing process diagram of the core material of this embodiment. 24 is a “artificial mineral fiber heat insulating material” (JIS A9504) which is a raw material of the core material 17 (17 in FIGS. 2 and 3), a core obtained by blending a binder material such as sodium silicate or phenol resin powder with a finely pulverized urethane. A plurality of core material raw materials 24 are stacked and heated and compressed by the upper mold 21 and the lower mold 22 to a predetermined thickness. When heat-compressing with a mold, if a binder material or the like adheres to this mold, the core material is difficult to release, so the release film 23 is inserted between the core material and the mold. If the above-mentioned organic material layer film is diverted without using 23, the release film 23 becomes unnecessary, which is advantageous in terms of manufacturing cost.

なお、発明者らの実験によれば、芯材17の原料として「人造鉱物繊維保温材」（JIS A9504）とバインダーとして「珪酸ナトリウム（珪酸ソーダ）」（JIS K1408）を使用した場合表１および表２の如くであった。つまり、バインダー原液を珪酸ソーダ1号、2号、3号として、各珪酸ソーダの濃度を重量パーセントで3％、5％、10％、20％とした場合の所定大きさの真空断熱材の初期熱伝導率は、表１に示すように珪酸ソーダ3号が最も良好であった。また、初期熱伝導率は珪酸ソーダの濃度が5％以下のほうが良好であったので、珪酸ソーダ3号について詳細実験をしたところ表２に示すように、珪酸ソーダの濃度が1％から5％の間では初期熱伝導率はほぼ良好であった。なお、珪酸ソーダの濃度が2％未満では、柔らかすぎて芯材原料としてのハンドリング性に難点が生じた。

According to the experiments by the inventors, when “artificial mineral fiber heat insulating material” (JIS A9504) is used as a raw material for the core material 17 and “sodium silicate (sodium silicate)” (JIS K1408) is used as a binder, Table 1 and It was as shown in Table 2. In other words, when the binder stock solution is sodium silicate Nos. 1, 2, and 3, and the concentration of each sodium silicate is 3%, 5%, 10%, and 20% by weight, the initial size of the vacuum heat insulating material of a predetermined size As shown in Table 1, thermal conductivity of sodium silicate No. 3 was the best. In addition, the initial thermal conductivity was better when the concentration of sodium silicate was 5% or less. As a result of a detailed experiment with sodium silicate 3, the concentration of sodium silicate was 1% to 5% as shown in Table 2. In between, the initial thermal conductivity was almost good. When the concentration of sodium silicate was less than 2%, it was too soft, causing a difficulty in handling as a core material.

Here, describing the maximum protrusion examples dimension T ₄ of the material particles such as 17f appearing on the surface 17a of the core 17 shown in FIG. 3 described above according to Table 3.

表３は、芯材17の原料として前述の「人造鉱物繊維保温材」を使用したものであるが、この「人造鉱物繊維保温材」の製造方法によっても、素材粒等の大きさ分布が異なる。製造方法としては、火炎挿入法とロータリー法がよく知られている。ここでは、火炎挿入法とロータリー法の両方について、かつ、３つの区分A、B、Cに分けて、その比率をパーセント（％）で表示してある。

Table 3 uses the above-mentioned “artificial mineral fiber heat insulating material” as a raw material of the core material 17, but the size distribution of the material grains and the like varies depending on the manufacturing method of this “artificial mineral fiber heat insulating material”. . As a manufacturing method, a flame insertion method and a rotary method are well known. Here, both the flame insertion method and the rotary method are divided into three categories A, B, and C, and the ratios are displayed in percent (%).

The aforementioned T ₄ dimensions classified as Category C a of less than 10 [mu] m, T ₄ dimensions classified as Category B those 10 m to 20 m, are shown above represents T ₄ size exceeds 20μm as division A. As shown in Table 1, in both the flame insertion method and the rotary method, the largest protruding dimension T ₄ of the material grains and the like is most often in the category C of less than 10 μm. In addition, regarding the distribution of A, B, and C, it is considered that the rotary method can be manufactured with less unevenness than the flame insertion method, which is simpler and more inexpensive.

However, even if the flame insertion method is used, it is advantageous in view of production efficiency and production cost if a material belonging to Category B can be used as a core material. That is, the manufacturing process be attained manufacturing cost of the vacuum heat insulator if the fabricated "artificial mineral fibers insulation material" is a and T ₄ size using those 20μm or less in a simple and inexpensive manufacture may flame Insertion Method It becomes.

  Accordingly, an example in which the gas barrier property of the metal foil 15 is not impaired over the long term for the core material of the raw material category B manufactured by the flame insertion method will be described with reference to Table 4.

表４の実施例１は、前述の表面保護フィルムとして15μｍのナイロン樹脂を使用し、アルミ金属蒸着膜を3μｍとし、このアルミ金属蒸着膜の支持層として10μｍのポリエチレンテレフタレート樹脂を使用し、アルミ金属箔を6μｍとし、内層フィルムとして20μｍの高密度ポリエチレン樹脂を使用した。また、外被材とは別に、芯材を覆う有機材フィルムとして20μｍのポリエチレンテレフタレート樹脂を使用した。

In Example 1 of Table 4, 15 μm nylon resin is used as the above-mentioned surface protective film, the aluminum metal vapor deposition film is 3 μm, and 10 μm polyethylene terephthalate resin is used as the support layer of the aluminum metal vapor deposition film. The foil was 6 μm, and a 20 μm high density polyethylene resin was used as the inner layer film. Separately from the jacket material, a 20 μm polyethylene terephthalate resin was used as an organic material film covering the core material.

  In addition, as a verification that does not impair the gas barrier properties in the long term, the initial value of the thermal conductivity and the sample after being left in the air at 60 ° C for 4 months can be judged by the deterioration of the thermal conductivity over time. The value was measured. The measurement was performed at an average temperature of 24 ° C. using a heat conduction measuring device HC-071 manufactured by Eiko Seiki Co., Ltd.

  In Example 2, 25 μm high-density polyethylene resin was used as the inner layer film, and 25 μm polyethylene terephthalate resin was used as the organic film, and the other conditions were the same as in Example 1.

  As shown in Table 4, the measured value after heating at 60 ° C. for 4 months is 7 to 8 mW / m · K in both Example 1 and Example 2, and is compared with 9 to 11 mW / m · K in Comparative Example 1. It was good. As a boundary that can withstand long-term use, when a vacuum heat insulating material is used for a refrigerator, 8 mW / m · K is a guideline, and it can be said that both Examples 1 and 2 are good.

  Further, by providing the organic material layer, it is possible to reduce the thickness of the inner layer film which is a heat-welded layer. In this example, it was confirmed that it could be 25 μm or less, and further 20 μm or less.

  As described above, according to the present embodiment, the outer cover material 20 covering the core material 17 of the vacuum heat insulating material 20, the surface protection film 12, the metal vapor deposition film 13, the metal foil 15, and the inner layer film 16 are configured. In addition, by interposing the organic material layer 18 between the inner layer film 16 and the surface of the core material 17, material particles, foreign matters, wrinkles, etc. having large diameters and particles appearing on the surface of the core material of the vacuum heat insulating material. Even if this occurs, since the metal foil 15 having gas barrier properties is not damaged, a refrigerator including a vacuum heat insulating material having excellent thermal conductivity can be provided even after a long period of time.

  In other words, if the total thickness of the inner layer film and the organic material film is set to 40 μm or more as in Example 1, the material particles, foreign matters, and soot that appear on the surface of the core of the vacuum heat insulating material appear. The metal foil having gas barrier properties is not damaged even if the above occurs, so that it is possible to provide a refrigerator structure including a vacuum heat insulating material having excellent thermal conductivity even after a long period of time. In addition, even if the metal foil 15 is damaged, it has the metal vapor deposition film 13 as its outer cover, so that the degree of vacuum can be maintained even after a long period of time, and thus a vacuum heat insulating material with excellent thermal conductivity. Can be provided.

  In addition, an organic material layer was coated on the surface of the core material 17 to reduce the thickness of the inner layer film covering the inner surface of the metal foil 15 of the jacket material 20. This layer is necessary for heat-sealing when sealing the inside of the jacket material, but it does not have enough strength to protect the metal foil with gas barrier properties from the irregularities on the surface of the core material, and itself is sufficient Since it does not have a gas barrier property, the amount of gas permeation from the inner layer film 16 which is a heat-welded layer can be reduced, so that a refrigerator including a vacuum heat insulating material having a high degree of vacuum for a long period can be provided.

  In addition, when the core material 17 is inserted into the jacket material 20, the organic material layer coated on the surface of the core material covers fine glass fiber scraps that are about to fall from the core material. Since the scrap does not adhere to the entrance of the jacket material 20, it is possible to provide a refrigerator including a vacuum heat insulating material having a high degree of vacuum for a long period of time.

  In addition, since the surface of the core material 17 is covered with an organic material layer film, and the thickness of the inner layer film 16 that covers the inner surface of the metal foil 15 of the outer cover material 20 is reduced, when the core material 17 is manufactured, the core material 17 Since the release film 23 for releasing the glass wool impregnated with the binder as a raw material from the mold used for heat compression can be eliminated, a refrigerator including a vacuum heat insulating material advantageous in terms of manufacturing cost can be provided.

  In addition, since the surface of the core material 17 is doubly covered with the organic material layer film and the inner layer film 16 of the outer cover material, material grains, foreign matters, wrinkles, etc., which appear on the core material surface, have large diameters and grains. However, it is possible to provide a refrigerator including a vacuum heat insulating material whose film layer is hard to be damaged. Further, since the inner surface of the inner layer film 16 is coated with an organic material layer film or an organic material layer coating, the core material 17 and the inner layer film 16 covering the inner surface of the metal foil 15 are not in direct contact with each other. Compatibility with is not a problem. Therefore, a core material and an inner layer film material can be arbitrarily selected, and a refrigerator including a vacuum heat insulating material advantageous in terms of manufacturing cost can be provided.

The longitudinal cross-sectional view of the refrigerator which shows the Example of this invention. The cross-sectional schematic diagram of the vacuum heat insulating material which shows the Example of this invention. The expanded cross-sectional schematic diagram of the vacuum heat insulating material which shows the Example of this invention. The manufacturing process figure of the core material which shows the Example of this invention. The cross-sectional schematic diagram of the vacuum heat insulating material which shows the Example of this invention. The expanded cross-sectional schematic diagram of the core material which shows the conventional trouble. FIG. 6 is a perspective view schematically illustrating the incorporation of a jacket material and a core material, showing conventional problems. The partial expanded cross-section schematic diagram of the vacuum heat insulating material which shows the conventional trouble.

Explanation of symbols

1 ... Refrigerator box, 2 ... Outer box, 3 ... Insulation material, 4 ... Inner box, 8,9 ... Cooler, 10 ... Compressor, 11 ... Vacuum insulation material, 12 ... Surface protection film, 13 ... Metal vapor deposition film , 14 ... support layer, 15 ... metal foil, 16 ... inner film, 17 ... core material, 18 ... organic material layer (film or coating) on the core material side, 19 ... organic material layer (film or coating) on the jacket material side ), 20 ... jacket material, 21 ... upper mold, 22 ... lower mold, 23 ... release film, 24 ... core material.

Claims (4)

A core material made of an inorganic fiber is covered with a jacket material having a gas barrier property, and is a vacuum heat insulating material configured by depressurizing the inside,
As the core material, a laminate of a plurality of artificial mineral fiber heat insulating materials is used,
The jacket material includes a surface protection film that protects the surface, a gas barrier layer that is formed of a metal that is located on the inner side of the surface protection film, and that is located on the inner side of the gas barrier layer and seals the inside of the jacket material. An inner layer film that can be welded as much as possible,
Between the jacket material and the core material, an organic material layer that covers the inner surface of the inner layer film and compresses the core material is interposed,
A vacuum heat insulating material, wherein a total thickness of the inner layer film and the organic material layer is 40 μm or more.   The vacuum heat insulating material according to claim 1, wherein the organic material layer has a thickness that retains the gas barrier property of the gas barrier layer even when locally compressed and deformed. The vacuum heat insulating material according to claim 1, wherein the organic material layer is an organic material layer that covers the core material separately from the jacket material. The vacuum heat insulating material according to any one of claims 1 to 3, wherein a polyethylene terephthalate resin of 20 µm or more is used as the organic material layer.

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