JP2007255689A - Vacuum heat insulating material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum heat insulating material having improved heat insulating performance by using an exterior body with high gas barrier performance for keeping the inside in a vacuum condition for a long period while reducing heat bridge phenomena which lower the heat insulating effect with heat transfer through the exterior body. <P>SOLUTION: The vacuum heat insulating material 10 is evacuated by filling a heat insulating core material 12 in the obverse and reverse exterior body 11. The obverse and reverse exterior body has a laminated structure in which at least two barrier film layers are provided with multiple inorganic oxide vapor deposition film layers. Its barrier film is a GX film (a trade name) made by Toppan Printing Co., Ltd. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum heat insulating material that exerts a heat insulating effect by being attached to a cold and heat insulating device such as a refrigerator, a vending machine, and a jar pot.

  Conventionally, various heat insulating materials have been used for refrigerators, vending machines, jar pots, and other cold insulation devices. Especially, as a heat insulating material with excellent heat insulating performance, a heat insulating core material is enclosed in the exterior body. However, a vacuum heat insulating material having a configuration in which the inside is evacuated is used. This exterior body needs to have an excellent gas barrier property in order to prevent the ingress of gas (air) from the outside and to keep the inside in a vacuum state for a long time. Therefore, conventionally, an exterior material having an aluminum foil layer with a thickness of about 6 to 20 μm in the constituent layer has been used as a barrier layer in order to impart high barrier properties.

However, the exterior material having an aluminum foil layer in the constituent layers is excellent in gas barrier properties, but because of the high thermal conductivity of aluminum itself, heat is transmitted through the aluminum foil layer, and the heat insulating effect is reduced. There was a problem of so-called heat bridge phenomenon. In order to solve this heat bridge phenomenon, a method of using a stainless steel foil layer having a relatively low thermal conductivity instead of an aluminum foil layer as a barrier layer (for example, see Patent Document 1), a glass vapor deposition film layer is used. Methods (for example, refer to Patent Document 2), methods using a ceramic vapor deposition layer (for example, refer to Patent Document 3), and the like have been known.
JP-A-8-159376 JP-A-7-113493 JP-A-8-152258

  However, in the method using the stainless steel foil layer as the barrier layer, the thermal conductivity of stainless steel is still high, so that the reduction of the heat bridge phenomenon is insufficient. In addition, the method using a glass vapor deposition film layer or the method using a ceramic vapor deposition layer as the barrier layer was sufficient to reduce the heat bridge phenomenon, but the gas barrier property was insufficient, and the vacuum state was maintained for a long period of time. Was impossible.

  The present invention solves the above-described problems in the conventional vacuum heat insulating material, and there is little heat bridge phenomenon in which the heat insulation effect is reduced due to heat transfer through the exterior body, and the gas barrier property of the exterior body is high and the internal vacuum is maintained over a long period of time. The present invention provides a vacuum heat insulating material that maintains its state and has good heat insulating performance.

  That is, according to the first aspect of the present invention, in the vacuum heat insulating material in which the heat insulating core material is sealed in the front and back exterior bodies, and the inside is evacuated, the front and back exterior bodies are in a laminated configuration, It is a vacuum heat insulating material characterized by having at least two barrier film layers each having an oxide vapor deposited film layer.

A second aspect of the present invention is the vacuum heat insulating material according to the first aspect, wherein the barrier film layer is a GX film (trade name) layer manufactured by Toppan Printing Co., Ltd.

  The vacuum heat insulating material of the present invention uses a laminated film having at least two barrier film layers having multiple inorganic oxide vapor-deposited layers as gas barrier layers of the front and back exterior bodies. Since the barrier film layer having multiple layers has poor heat conduction as compared with the aluminum foil layer, a vacuum heat insulating material using a laminated film having an aluminum foil layer as a gas barrier layer in a constituent layer on a conventional front and back exterior body Compared with, there is little heat bridge phenomenon that a heat insulation effect falls by heat transfer through an exterior body. Note that a GX film (trade name) manufactured by Toppan Printing Co., Ltd. is used as a barrier film having a multilayer inorganic oxide vapor deposition layer.

  Moreover, the vacuum heat insulating material of the present invention uses a laminated film having a barrier film layer having two inorganic oxide vapor-deposited layers as gas barrier layers on the front and back exterior bodies, and a gas barrier for the exterior body. Therefore, the internal vacuum state is maintained over a long period of time, and the heat insulation performance is maintained well.

  As shown in FIG. 1 (a), the vacuum heat insulating material (10) of the present invention is one in which the heat insulating core material (12) is evacuated and sealed in the front and back exterior bodies (11). The front and back exterior bodies have a laminated structure, and the laminated structure has at least two barrier film layers each having an inorganic oxide vapor-deposited film layer. GX film (trade name) manufactured by Toppan Printing Co., Ltd. is used as the barrier film layer having a multi-layered inorganic oxide vapor-deposited film layer. Film layer / Toppan Printing Co., Ltd. GX film layer / High-density polyethylene film layer [core material side] configuration, [Outside] Nylon film layer / Toppan Printing Co., Ltd. GX film layer / Toppan Printing Co., Ltd. GX film layer / High Density polyethylene film layer [core material side] configuration, [Outside] Toppan Printing Co., Ltd. GX film layer / Toppan Printing Co., Ltd. GX film layer / nylon film layer / high density polyethylene film layer [core material side] configuration, etc. . The high-density polyethylene layer used on the core material side of the laminated film is a sealant layer, and the density is 0.941 to 0.965 in order to prevent the barrier from decreasing from the end face of the vacuum heat insulating material and maintain the degree of vacuum. High density polyethylene is used. The nylon film layer is used for imparting pinhole resistance. Moreover, as a heat insulating core material, a powder silica molded object, a calcium silicate molded object, a polyurethane foam, etc. are used.

<Example 1>
First, 3 g / m ^{2 of} urethane adhesive is applied to a GX film (trade name) manufactured by Toppan Printing Co., Ltd., which is a barrier film having two 12 μm thick inorganic oxide vapor-deposited layers, and a 25 μm thick nylon film is bonded. GX film manufactured by Toppan Printing Co., Ltd. (trade name), which is a barrier film having 2 layers of 12 μm-thick inorganic oxide vapor-deposited layers coated with 3 g / m ^{2 of} urethane adhesive on the nylon film surface of the two-layer laminated film. ), 3 g / m ^{2 of} urethane adhesive was applied to the GX film surface of this three-layer laminated film, and a 50 μm thick high-density polyethylene film was laminated, as shown in FIG. ] GX film layer (111) manufactured by Toppan Printing Co., Ltd./nylon film layer (112) / GX film layer manufactured by Toppan Printing Co., Ltd. (113) / high density polyethylene A laminated film A (110) having a film layer (114) [core material side] configuration is prepared (in the figure, 115 is an adhesive layer). The molded body of powdered silica was vacuum-sealed as a heat insulating core material in the three-sided seal bag for the exterior body to produce a vacuum heat insulating material (10) of Example 1 shown in FIG.

<Comparative Example 1>
First, 3 g / m ^{2 of} urethane adhesive is applied to a 12 μm thick polyethylene terephthalate film and a 15 μm thick nylon film is bonded to the nylon film surface of this two-layer laminated film. Apply m ^{2 and} paste a 6 μm thick aluminum foil, apply 3 g / m ^{2 of} urethane adhesive to the aluminum foil surface of this three-layer laminated film, and bond 50 μm thick high density polyethylene. 2 (a) [Outside] Laminated film B (polyethylene terephthalate film layer (121) / nylon film layer (122) / aluminum foil layer (123) / high density polyethylene film layer (124) [core material side] laminated film B ( 120) (125 is an adhesive layer in the figure), and then, as in Example 1, this laminated film B is There was prepared a three-way seal bag for exterior body, the three-way seal bag for the exterior body, molded bodies of powdered silica was prepared vacuum heat insulating material of Comparative Example 1 was vacuum sealed as a heat insulating core material.

<Comparative example 2>
First, 3 g / m ^{2 of} urethane adhesive is applied to a GL film (trade name) manufactured by Toppan Printing Co., Ltd., which is a barrier film having a 12 μm thick inorganic oxide vapor deposition layer, and a 25 μm thick nylon film is bonded. Then, 3 g / m ^{2 of} urethane adhesive was applied to the nylon film surface of this two-layer laminated film, and a 50 μm thick high-density polyethylene film was bonded together, and the [outside] letterpress printing stock shown in FIG. A laminated film C (130) having a GL film layer (131) / nylon film layer (132) / high-density polyethylene film layer (133) [core material side] made by the company was prepared (134 in the figure is an adhesive layer) Next, in the same manner as in Example 1, a three-sided seal bag for an exterior body was produced using the laminated film C, and a powder sheet as a heat insulating core material was formed on the three-side seal bag for the exterior body. The Rika compact was vacuum-sealed to produce a vacuum heat insulating material of Comparative Example 2.

<Characteristic evaluation>
Next, the characteristics of the three types of vacuum heat insulating materials of Example 1, Comparative Example 1 and Comparative Example 2 were comparatively evaluated. The evaluation results are shown in Tables 1 and 2. Table 1 shows the evaluation results of gas barrier properties and thermal conductivity of the vacuum heat insulating material, and Table 2 shows the evaluation results of moisture resistance and puncture strength of the laminated film of the exterior body.

実施例１の真空断熱材は、表裏の外装体が、バリア層として凸版印刷株式会社製ＧＸフィルム（商品名）層を２層有する積層フィルムであり、比較例１の真空断熱材は、表裏の外装体が、バリア層としてアルミニウム箔層する積層フィルムであるため、表１の真空断熱材の特性評価結果に示されているように、実施例１の真空断熱材は、比較例１の真空断熱材と比較して外装体の熱伝導性が小さく、断熱効果が低下するヒートブリッジ現象が少なく、従って、実施例１の真空断熱材は、比較例１の真空断熱材と比較して断熱性が良好であった。また、実施例１の真空断熱材は、比較例２の真空断熱材と比較してバリア性が良好であり、長期にわたって表裏の外装体内の真空状態が保たれ、良好な断熱性能が長期維持された。

The vacuum heat insulating material of Example 1 is a laminated film in which the front and back exterior bodies have two GX film (trade name) layers manufactured by Toppan Printing Co., Ltd. as a barrier layer. Since the outer package is a laminated film having an aluminum foil layer as a barrier layer, the vacuum heat insulating material of Example 1 is the vacuum heat insulating material of Comparative Example 1 as shown in the characteristics evaluation results of the vacuum heat insulating material of Table 1. The heat conductivity of the exterior body is small compared to the material, and the heat bridge phenomenon in which the heat insulating effect is reduced is small. Therefore, the vacuum heat insulating material of Example 1 has a heat insulating property compared to the vacuum heat insulating material of Comparative Example 1. It was good. Moreover, the vacuum heat insulating material of Example 1 has a good barrier property as compared with the vacuum heat insulating material of Comparative Example 2, the vacuum state in the front and back exterior bodies is maintained for a long time, and good heat insulating performance is maintained for a long time. It was.

  In addition, as shown by the characteristic evaluation result of the laminated film in Table 2, the laminated film A, which is an exterior body of the vacuum heat insulating material of Example 1, was extremely good in moisture resistance and strong in puncture strength. Laminated film B, which is an exterior body of the vacuum heat insulating material of Comparative Example 1, is inferior in puncture strength as compared to Laminated film A and Laminated film C, and Laminated film C, which is an exterior body of the vacuum heat insulating material of Comparative Example 2, The moisture resistance was inferior to the laminated film A.

(A) is sectional drawing which shows the structure of the vacuum heat insulating material of Example 1, (b) is sectional drawing which shows the structure of the laminated | multilayer film A used for the exterior body. (A) is sectional drawing which shows the structure of the laminated film B used for the exterior body of the vacuum heat insulating material of the comparative example 1, (b) is the laminated film used for the exterior body of the vacuum heat insulating material of the comparative example 2. It is sectional drawing which shows the structure of C.

Explanation of symbols

10 ... Vacuum heat insulating material 11 ... Exterior body 12 ... Thermal insulating core material 110 ... Laminated film A
111, 113 ... GX film layer 112, 122, 132 ... Nylon film layer 114, 124, 133 ... High density polyethylene film layer 115, 125, 134 ... Adhesive layer 120 ... Laminated film B
121 …… Polyethylene terephthalate film layer 123 …… Aluminum foil layer 130 …… Laminated film C
131 …… GL film layer

Claims (2)

  In a vacuum heat insulating material in which a heat insulating core material is enclosed in front and back exterior bodies and the inside is evacuated, the front and back exterior bodies have a laminated structure, and a barrier film layer having multiple layers of inorganic oxide vapor deposited film layers in the laminated structure The vacuum heat insulating material characterized by having at least two layers.   2. The vacuum heat insulating material according to claim 1, wherein the barrier film layer is a GX film (trade name) layer manufactured by Toppan Printing Co., Ltd.

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