JP2007263335A - Vacuum insulating material, hot water supply device using vacuum insulating material, and electric water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum insulating material capable of maintaining high heat insulation performance even in a high temperature environment, and to provide a hot water supply device having high heat insulation performance. <P>SOLUTION: The vacuum insulating material has a core material 51 comprising an inorganic fiber aggregate, an outer wrapping material 52 having a surface protective layer, a gas barrier layer, and a fusion bonding layer, and an adsorbent 53 for adsorbing moisture and gas components of the core material 51 and the outer wrapping material 52. The gas barrier layer of the outer wrapping material 52 has at least two layers of metal layers laminated so that the metal surfaces face each other as a first gas barrier layer and a second gas barrier layer. A resin film having a fusion point of 150°C or higher is used as the fusion bonding layer. Thereby, heat insulating performance can be maintained over a long period of time even in a high temperature environment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum heat insulating material, a hot water supply device using the vacuum heat insulating material, and an electric water heater.

  In recent years, from the viewpoint of global warming, the necessity of reducing the amount of power consumption in home appliances has been screamed. For example, refrigerators are products that consume power consumption among household electrical appliances, and reducing the power consumption of refrigerators is indispensable as a measure against global warming. Under such circumstances, refrigerators employing vacuum heat insulating materials have been commercialized, and the heat transfer efficiency is remarkably improved by suppressing useless heat exchange with the outside.

  The main application fields of the current vacuum insulation material are products with relatively low temperature zones such as refrigerators, cryogenic freezers, transport cool boxes, and cool containers. However, vacuum insulation materials have good heat insulation performance, and recently, application to products with relatively high temperature zones such as bathtubs and vending machines has begun to be examined.

  In order to be applied to such a relatively high temperature product field, it is required that the material constituting the vacuum heat insulating material can sufficiently withstand the temperature range. The heat resistance temperature of the outer packaging material used for the vacuum heat insulating material is one example, and conventional examples include those shown in Patent Documents 1 and 2.

(Prior art 1)
Although the vacuum heat insulating material shown by patent document 1 is an example which applied the vacuum heat insulating material to the electric water heater, the laminated film of the vacuum heat insulating material which sealed the space between the heat resistant laminated films which have arrange | positioned the core material in vacuum. The seal layer, the gas barrier layer, and the protective layer are arranged so that the heat seal portion is folded near the outside of the electric water heater. Since the temperature of the electric water heater rises to about 100 ° C., conventional organic heat insulating materials such as urethane are deteriorated, and there is a problem that the heat insulating property is extremely deteriorated. In order to solve these problems, the vacuum heat insulating material of Patent Literature 1 uses unstretched polypropylene as the sealing layer with the outer packaging material having the above-described configuration. By using this, it is configured to have heat resistance, and the heat seal portion is located near the outside of the water heater to suppress deterioration from the heat seal portion.

(Prior art 2)
Moreover, the example of the electric water heater shown by patent document 2 provides a vacuum heat insulating material in the outer periphery of a water storage container, and heat insulation power is reduced very much. This is because the gas barrier layer in the laminated film constituting the vacuum heat insulating material uses a metal foil on the side exposed to a high temperature, uses a vapor deposition layer on the low temperature side, and has a gas barrier property at a temperature of about 100 ° C. on the high temperature side. Is good and can maintain a vacuum state, and heat insulation can be maintained for a long time. Further, by using a vapor deposition layer on the low temperature side, the heat flowing in through the metal foil is suppressed and the performance of the entire vacuum heat insulating material is improved, and the power consumption is reduced.

JP-A-11-309069 JP 2001-8828 A

  The vacuum heat insulating material shown in Patent Document 1 uses aluminum foil and unstretched polypropylene for improving gas barrier properties and heat resistance, respectively, but pinholes are seen in thin aluminum foils such as 6 μm. There is concern about the deterioration of gas barrier properties. Moreover, there is no presentation of a specific countermeasure for the deterioration of gas barrier properties due to the use of unstretched polypropylene, and there is a problem in terms of reliability.

  Moreover, although the vacuum heat insulating material shown by patent document 2 has suppressed the heat | fever (heat bridge) which flows in along a vapor deposition layer by using a metal foil layer on the high temperature side and a vapor deposition layer on the low temperature side, Since the gas barrier property is inferior to that of the metal foil, the gas intrusion amount from the low temperature side vapor deposition layer is increased. That is, there was a problem in terms of reliability.

  Further, as a new problem in use in a high temperature environment, there is an influence of an organic gas generated from the laminate film. According to the experiments by the inventors, the film laminated using an adhesive such as a two-component curable urethane is heated to about 80 ° C., and then methyl alcohol, ethyl acetate, toluene, styrene, etc. It was confirmed that the solvent-based gas was desorbed. This causes a phenomenon in which organic gas components such as components and components generated by decomposition are desorbed. When there is a material having a high gas barrier property such as an aluminum foil, the gas generated in the inner layer is difficult to escape to the outer layer side, and thus passes through the heat welding layer on the interior side. Moisture / gas adsorbents that have been conventionally used in low-temperature environments such as refrigerators cannot adsorb these organic solvent gases, and therefore cannot maintain the vacuum degree of the vacuum heat insulating material. Therefore, as a result, the heat insulation performance is deteriorated.

  The adsorbent is not described in Patent Documents 1 and 2, and is not considered for these problems.

  An example of a conventional vacuum heat insulating material will be described below with reference to FIGS.

  FIG. 9 is a cross-sectional view of a vacuum heat insulating material arrangement portion of a product to which a vacuum heat insulating material is applied. In the drawing, the temperature difference is described in terms of “high temperature side” and “low temperature side” for convenience. FIGS. 10 and 11 show examples of the cross section of the film 12a disposed on the high temperature side and the cross section of the film 12b disposed on the low temperature side, respectively.

As shown in FIG. 9, the vacuum heat insulating material 10 generally includes a core material 11 and an outer packaging material 12, and is attached to a wall material 20 on the high temperature side with an adhesive (not shown) or the like, with a space 25 interposed therebetween. A heat insulating portion is constituted by the wall material 21 on the low temperature side. Also, an adsorbent is used to maintain the internal vacuum. The space 25 may be a hard urethane foam or other heat insulating material.

  Among these, the structure of the film disposed on the high temperature side of the outer packaging material 12 includes a surface protective layer 14, gas barrier layers 15 and 16, and a heat welding layer 17, as shown in FIG. In many cases, an aluminum foil is used for the gas barrier layer 16 so as not to deteriorate the gas barrier property.

  Moreover, as a structure of the film arrange | positioned at the low temperature side of the outer packaging material 12, as shown in FIG. 11, it is the same as the high temperature side of FIG. 10 except that the resin film may be deposited on the substrate as the gas barrier layer 18. It is a configuration.

On the high temperature side, there is concern about the effects of aluminum foil pinholes, and on the low temperature side, the aluminum vapor deposited layer is inherently inferior to the aluminum foil in gas barrier properties, and in any configuration, the gas barrier properties tend to decrease. . In addition, due to the influence of the high temperature side, an organic gas component is generated from an adhesive, a solvent, or the like from the laminate portion of the outer packaging material 12, but this was not considered.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a vacuum heat insulating material capable of maintaining high heat insulation performance even in a high temperature environment, or to provide a hot water supply device having high heat insulation performance. Yes.

  Accordingly, the present invention seeks to solve the problems of such a conventional configuration and new problems that occur at high temperatures, and includes at least a core made of an inorganic fiber polymer, a surface protective layer, A vacuum heat insulating material comprising an outer packaging material having a gas barrier layer and a heat-welding layer, and an adsorbent that adsorbs moisture and gas components of the core material and the outer packaging material, wherein the gas barrier layer of the outer packaging material is at least two layers of metal The metal layers constituting the gas barrier layer of the outer packaging material are mutually laminated by forming a vacuum heat insulating material characterized by laminating so that the metal surfaces of the layers face each other and laminating a resin film having a melting point of 150 ° C. or higher as a heat welding layer. It can be used at high temperatures up to around 110 ° C due to the structure that compensates for the factors that deteriorate the gas barrier properties due to pinholes and the high melting point of the heat-welded layer. It can be greatly improved.

  The vacuum heat insulating material of the present invention includes a core material made of an inorganic fiber polymer, an outer packaging material having a surface protective layer, a gas barrier layer, and a heat welding layer, and an inner packaging material that holds the core material in a compressed state in the thickness direction. And a vacuum heat insulating material including an adsorbent that adsorbs moisture and gas components of the core material, the outer packaging material, and the inner packaging material, and the gas barrier layer of the outer packaging material has at least two metal parts sandwiching the adhesive layer A first and second gas barrier layers, wherein the first gas barrier layer is a film having a metal film formed on one side of a resin film substrate, and the second gas barrier layer is a metal foil or a resin film base; A film in which a metal film is formed on one side of a material and a film in which a gas barrier resin is coated on the metal film are formed, and a resin film layer / metal film / adhesive layer / metal foil and a resin film layer / metal film / gas barrier, respectively. sex Laminated with a combination of a grease coating layer / adhesive layer / metal film / resin film layer, a resin film having a melting point of 150 ° C. or more as a heat welding layer on the innermost side of the gas barrier layer, and an outer layer of the gas barrier layer The outer layer is a laminate of a resin film having a melting point higher than that of the heat-welded layer on the side as a surface protective layer, and the core material does not contain a binder and has resilience in the thickness direction, and the adsorbent is Since it is housed in a housing part that is cut obliquely with respect to the surface of the core material or in the thickness direction, the openings of the housing part are overlapped and narrowed, so that ingress of gas and moisture from the outside Can be prevented.

  In addition, since at least a hydrophobic adsorbent is used as the adsorbent, the organic gas can be adsorbed even in a high-temperature atmosphere, so that deterioration of the heat insulation performance can be suppressed and the degree of vacuum can be maintained for a long time.

Further, the vacuum heat insulating material of the present invention is the vacuum heat insulating material having any one of the above-described structures, wherein the outer packaging material is composed of first and second gas barrier layers, and the first gas barrier layer is a polyamide resin film. (PA), ethylene vinyl alcohol copolymer resin film (EVOH), polyvinyl alcohol resin film (PVA), polyethylene terephthalate resin film (PET) as a base material, aluminum (AL) on one side, A metal film of any one of stainless steel (SUS) is used as the second gas barrier layer, using a metal foil of any of aluminum foil (AL), stainless steel foil (SUS), and iron foil (Fe), A laminated film bonded so that the metal layers of the first and second gas barrier layers face each other; A multilayer laminate structure in which either an unstretched polypropylene resin film (CPP) or a polybutylene terephthalate resin film (PBT) is used as the welding layer, and the surface protective layer has a higher melting point than the thermal welding layer. Since the metal film directly closes the pinhole peculiar to the metal foil, the gas barrier property is high, and the intrusion of gas and moisture from the outside can be suppressed.

Further, the vacuum heat insulating material of the present invention is the vacuum heat insulating material having any one of the above-described structures, wherein the outer packaging material is composed of first and second gas barrier layers, and the first gas barrier layer is a polyamide resin film. (PA), ethylene vinyl alcohol copolymer resin film (EVOH), polyvinyl alcohol resin film (PVA), polyethylene terephthalate resin film (PET) as a base material, aluminum (AL) on one side, A stainless steel (SUS) metal film is used as the second gas barrier layer as an ethylene vinyl alcohol copolymer resin film (EVOH), polyvinyl alcohol resin film (PVA), polyethylene terephthalate resin film (PET). ) Any one of the resin films as a base material The resin coating layer is provided on one surface of the metal film of aluminum (AL) or stainless steel (SUS), and the two metal films face each other with the resin coating layer interposed therebetween. A laminated film that is laminated and uses either a non-stretched polypropylene resin film (CPP) or a polybutylene terephthalate resin film (PBT) as a heat-welding layer, and the surface protective layer has a higher melting point than the heat-welding layer By adopting a multilayer laminate structure as a film, it is possible to achieve both high performance and long-term reliability by reducing the heat bridge of the outer packaging material, improving the gas barrier property by sandwiching the resin coating layer with two metal films.

Further, the present invention uses a high-silica zeolite having a SiO ₂ / Al ₂ O ₃ ratio of 20 or more and incombustible as the hydrophobic adsorbent in the vacuum heat insulating material having any one of the above-described configurations. Therefore, it is possible to preferentially adsorb organic solvent gases such as toluene and methanol having a small molecular diameter and a relatively low boiling point.

  Further, the present invention in a hot water supply device is arranged such that any one of the above vacuum insulation materials is bent in an arc shape along the outer periphery of the hot water storage tank in an electric or heat pump type hot water supply device including at least a hot water storage tank. It is characterized in that the heat insulation at the end of the arc is arranged at least twice, and the amount of heat leakage is reduced by arranging the vacuum heat insulating material with improved heat resistance and gas barrier properties without gaps, Long-term insulation performance can be maintained.

  Further, the present invention in an electric water heater having at least a hot water heating function and a heat retaining function, and comprising an outer container, a water storage container, and a lid portion, is provided with any one of the above vacuum insulation materials along the outer periphery of the water storage container. The end of the vacuum heat insulating material in the bending direction is doubly arranged, and heat leakage from the water storage container is reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the vacuum heat insulating material which can maintain a high heat insulation performance also in a high temperature environment can be provided. Moreover, since a vacuum heat insulating material can be used even in a high temperature environment, a hot water supply device having high heat insulating performance can be provided.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a vacuum heat insulating material according to an embodiment of the present invention, and FIGS. 2 and 3 are enlarged cross-sectional views for explaining a difference in film stacking structure of an outer packaging material 52 in FIG.

  1 and 2, the vacuum heat insulating material 50 includes four layers of a core material 51 made of an inorganic fiber polymer, a surface protective layer 55, a first gas barrier layer 56, a second gas barrier layer 57, and a heat welding layer 58. Is composed of an outer packaging material 52, an adsorbent 53, a core material 51 and an inner packaging material 54 that encloses the adsorbent 53. is there.

  The core material 51 made of the inorganic fiber polymer used here is preferably an inorganic fiber polymer such as glass fiber (glass wool, glass fiber), silica fiber, alumina fiber, silica alumina fiber, ceramic fiber, but is particularly limited. is not.

  In addition, the gas barrier property of the outer packaging material 52 is ensured by combining the gas barrier layers 56 and 57. Here, in order to enhance the gas barrier property, a metal is used for both the first gas barrier layer 56 and the second gas barrier layer 57. A layer was provided. As the metal layers of these gas barrier layers, those obtained by forming a metal film using a metal foil or a resin film as a base material are used. The metal foil is not particularly limited, such as aluminum foil, stainless steel foil, iron foil, copper foil, titanium foil and the like.

The method for forming the metal film is not particularly limited as long as the film thickness is in the range of 300 to 1,000 mm, such as vacuum deposition, sputtering, and ion plating. Further, the adhesive (not shown) is not particularly limited except for a specific portion, and an adhesiveless material such as extrusion lamination or heat lamination can be used.

  As for the adsorbent 53, when the vacuum heat insulating material 50 is used in a high-temperature atmosphere, a hydrophobic adsorbent is used so that the laminate film of the outer packaging material 52, the adhesive for laminating, and the solvent-based residue used at the time of laminating are used. Since the organic gas component generated from the above can be preferentially adsorbed, the heat insulating performance can be maintained for a longer period.

  FIG. 3 shows a configuration of an outer packaging material different from that in FIG. 2, and a resin material is coated on the vapor deposition surface of the metal vapor deposition layer of the second gas barrier layer 59. Specifically, it will be described in the description of each embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. The same reference numerals in the respective embodiments indicate the same or equivalent components, and are basically the same as those in the first embodiment except for the points described in the description of each embodiment. Because of this, redundant explanation is omitted.

  Table 1 shows an outline of Examples 1 to 6 and Comparative Examples 1 to 4 described first. In each example, the initial thermal conductivity and the thermal conductivity after the lapse of five years were measured for the film structure and adsorbent of each outer packaging material, and the deformation state such as appearance was observed.

  In the first embodiment, the film configuration of the outer packaging material 52 in the vacuum heat insulating material 50 shown in FIG. 1 is configured as shown in FIG. As the core material 51, a glass wool laminate not containing a binder having an average fiber diameter of 4 μm was used.

  The specific structure of the outer packaging material 52 of Example 1 is shown. A polyamide film (ONY) is used for the outermost surface protective layer 55, and the first gas barrier layer 56 provided inside the surface protective layer 55 is made of polyethylene terephthalate (PET) as a resin film 56a and a metal vapor-deposited layer 56b. Aluminum was vapor-deposited with a thickness of 400 to 500 mm. The second gas barrier layer 57 was made of iron-containing aluminum foil (AL) having a thickness of 6 μm. The aluminum vapor deposition surface of the first gas barrier layer 56 and the aluminum foil of the second gas barrier layer 57 are bonded to face each other. An adhesive having a melting point higher than that of the heat welding layer 58 was used for bonding the metal vapor deposition layer and the metal foil layer. An unstretched polypropylene film was used for the heat welding layer 58, and the heat resistance temperature of the outer packaging material 52 as a whole was improved.

  For the adsorbent 53 accommodated in the core material 51, hydrophilic synthetic zeolite having an average pore diameter of 9 mm was used. The hydrophilic synthetic zeolite is a physical adsorbent and adsorbs a gas having a molecular diameter smaller than the pore diameter. Further, the inner packaging material 54 is provided between the outer packaging material 52 and the core material 51, and the core material 51 is wrapped inside the outer packaging material 52. However, the inner packaging material 54 may not be used. The outer packaging material 52 covers the core material 51 and the adsorbent 53 from the outside while being encapsulated in the inner packaging material 54.

  The gas barrier property of the outer packaging material 52 is a combination of a metal foil layer made of aluminum foil and a metal vapor deposited layer formed by aluminum vapor deposition, so that the metal vapor deposited layer closes pinholes unique to the metal foil, resulting in enhanced gas barrier properties. can do. The adhesion between the layers of the film of the outer packaging material 52 uses a two-component curing type polyester-type urethane adhesive, but is not particularly limited except for bonding two metal layers composed of a vapor deposition layer and a foil layer. . The adhesive will be described later.

  The vacuum heat insulating material 50 is obtained by drying a core material 51 made of a glass wool laminate at 230 ° C. for a predetermined time, making an oblique cut with respect to the thickness direction of the core material 51, and introducing an adsorbent 53. , Compressed in the thickness direction of the core material 51 together with the inner packaging material 54, deaerated inside, and once sealed. This is put into the outer packaging material 52 which has been subjected to a drying treatment, and is obtained by heat-welding one end of the outer packaging material 52 after maintaining one end of the inner packaging material 54 at a vacuum degree of 2.2 Pa or less for a certain period of time in an open state. Can do.

  Since the adsorbent 53 is housed in an oblique cut provided in the restoring core material 51, the openings are overlapped and narrowed after evacuation, and the core material 51 does not scatter. Further, since no binder is used for the core material 51, the presence of the core material 51 does not serve as an adsorption resistance when adsorbing gas components and moisture inside the outer packaging material 52.

  Add more about the adhesive. In this embodiment, the degree of vacuum inside the outer packaging material 52 is maintained by welding the heat welding layer 58, and the melting point of the heat welding layer 58 is naturally the temperature at which the vacuum heat insulating material is used (for example, a water heater). Higher than 110 ° C.). Further, the temperature of the heat source for welding the heat welding layer 58 is naturally higher than the melting point of the heat welding layer 58.

  As described above, it is necessary to use an adhesive for bonding the metal layers that is not only higher than the melting point of the heat welding layer 58 but also higher than the welding temperature. At this time, even when the heat-welding layer 58 is heat-welded in the manufacturing process, the adhesion between the metal layers is not released, and high gas barrier properties can be maintained.

  In this embodiment, an adhesive made of a thermosetting resin was used for adhesion between the metal foil layer and the metal vapor deposition layer. A thermosetting resin is a resin that hardens when heated, and a thermosetting material is suitable when it is used in a high temperature environment because it does not become soft even after being reheated once cured. Specifically, it is a polyester polyol-based / polyisocyanate urethane-based adhesive. This adhesive performs adhesion by generating a urethane bond by reacting a polyester polyol and a polyisocyanate. That is, a urethane bond is formed in the produced adhesive film. Therefore, it can be said that it is a polyurethane adhesive type polyester adhesive.

  Such an adhesive may break the urethane bond at a certain temperature. Microscopically, the adhesive in the present example is said to partially break the urethane bond from about 200 ° C., but the adhesive is not peeled off. The actual time required for heat welding is about 1 to 2 seconds, and the melting point of the heat welding layer is about 160 ° C. Therefore, even if the outer packaging material 52 is heat welded, the adhesion is not peeled off.

  Actually, even when the temperature of the heat source at the time of heat welding was 180 to 200 ° C. and the outer packaging material 52 was heat welded, the adhesion was not peeled off. Furthermore, no deterioration was observed in the adhesive layer even when a 1-minute heat welding operation was performed at a heat source temperature of 200 ° C. or higher.

  Also, the so-called heat bridge is caused by the high thermal conductivity of the metal layer, among the components of the outer packaging material 52. That is, in an actual usage mode, the temperature of the metal layer (in Example 1, the aluminum foil and the aluminum deposited film) tends to be high. Therefore, the adhesion between the two metal layers is easily removed as compared with the adhesion between the other layers.

  In this embodiment, since the adhesive made of the above-mentioned thermosetting resin is used, high gas barrier properties can be maintained even when used for a long time. Even if an adhesive made of a thermosetting resin is not used, the same effect can be expected even if an adhesive having a melting point higher than the melting point and the heat welding temperature (heat source temperature) of the heat welding layer is used.

  The heat conductivity indicating the heat insulating performance of the vacuum heat insulating material 50 thus obtained was measured at an average temperature of 24 ° C. with a heat conductivity measuring device AUTO-Λ manufactured by Eihiro Seiki Co., Ltd. The vacuum heat insulating material 50 to be measured will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a vacuum heat insulating material 50 for measuring thermal conductivity. As in the example shown in FIG. 1, the core material 51 is covered with the outer packaging material 52, and the inside is sealed in a decompressed state. A portion surrounded by a broken line is an ear portion 52 a of the outer packaging material 52. In this way, the ear 52a is present at the peripheral edge of the outer packaging material 52, and in many cases it is used by being bent in an actual use mode (see FIG. 1), but as shown in FIG. The thermal conductivity was measured without bending the part 52a.

  When the thermal conductivity was measured, the initial value was as good as 0.0022 (W / m · K). Moreover, about the deterioration of the heat insulation performance in the use in a high temperature environment, the maximum use temperature was 110 degreeC, and it compared by the thermal conductivity value after progress for five years which considered fixed use conditions. The thermal conductivity value after the lapse of 5 years in this example was 0.0063 (W / m · K), and it was confirmed that sufficient heat insulating performance was maintained. Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

  In the second example, the vacuum heat insulating material 50 was manufactured under the same conditions as in Example 1 except that the adsorbent 53 was calcium oxide. Calcium oxide is a hydrophilic chemical adsorbent and adsorbs moisture to form calcium hydroxide.

  The heat conductivity indicating the heat insulating performance of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.0021 (W / m · K) after 5 years. The thermal conductivity value was 0.0065 (W / m · K), and it was confirmed that sufficient heat insulation performance was maintained. Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

In the third example, the vacuum heat insulating material 50 was manufactured under the same conditions as in Example 1 except that the adsorbent 53 was used in combination with a hydrophobic synthetic zeolite having an average pore diameter of 6 mm or more and a hydrophilic synthetic zeolite having an average pore diameter of 9 mm. . The hydrophobic synthetic zeolite is a high-silica zeolite that is a physical adsorbent, has a SiO ₂ / Al ₂ O ₃ ratio of 20 or more, and is nonflammable.

The heat conductivity indicating the heat insulating property of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.0022 (W / m · K), after 5 years. The thermal conductivity value of was good at 0.0059 (W / m · K). Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

  In Example 3, a hydrophilic adsorbent and a hydrophobic adsorbent are used in combination, so that the hydrophilic adsorbent preferentially adsorbs moisture, and the hydrophobic adsorbent adheres to the laminate film or laminate for the outer packaging material 52. Since the organic gas components generated from the solvent and the solvent-based residue used at the time of lamination are preferentially adsorbed, it is considered that the heat insulation performance can be maintained high for a long period of time as compared with Example 1. In particular, it has been found that it is effective to use both adsorbents in a high temperature environment where organic gas is easily generated.

  In the fourth example, the vacuum heat insulating material 50 was manufactured under the same conditions as in Example 1, except that the adsorbent 53 was used in combination with a hydrophobic synthetic zeolite having an average pore diameter of 6 mm or more and calcium oxide.

The heat conductivity indicating the heat insulating property of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.000020 (W / m · K) after 5 years. The thermal conductivity value of was good at 0.0059 (W / m · K). Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

  Example 4 shows that it is effective to use a hydrophilic adsorbent and a hydrophobic adsorbent in the same manner as in Example 3. This effect was found to be effective even when the hydrophilic adsorbent is a chemical adsorbent. Calcium oxide is a chemical adsorbent that adsorbs only moisture, and once it adsorbs moisture, it is not released in a normal environment.

Even when such a chemical adsorbent is used, from the result of maintaining the same thermal insulation performance as Example 3 after 5 years,
(1) Adsorption of organic gas is necessary to ensure long-term reliability. (2) To adsorb organic gas over a long period of time, adsorb organic gas, not a hydrophilic adsorbent that can also adsorb organic gas. It was found that (1) and (2) that the use of a possible hydrophobic adsorbent is effective.

  In the fifth embodiment, in the vacuum heat insulating material 50 shown in FIG. 1, the film structure of the outer packaging material 52 is configured as shown in FIG. 3, and the second gas barrier layer 59 is made of an ethylene vinyl alcohol copolymer resin film. 59a was used as a base material, and aluminum was deposited in a thickness of 400 to 500 mm to form a vapor deposition layer, and a resin material was coated on the vapor deposition surface (layer 59b composed of a metal vapor deposition layer and a resin coating layer). As in Example 3, the adsorbent 53 used was a hydrophobic synthetic zeolite having an average pore diameter of 6 mm or more and a hydrophilic synthetic zeolite having an average pore diameter of 9 mm. Other conditions are the same as those in the first embodiment.

  The reason why the second gas barrier layer 59 of the outer packaging material 52 is vapor-deposited with aluminum is to reduce the heat bridge as compared with the aluminum foil, and to realize a gas barrier property close to that of the aluminum foil in order to supplement the gas barrier property. The material is coated. The material used for coating the resin material only needs to be flexible, and examples thereof include, but are not limited to, polyacrylic acid type and epoxy type.

  When the thermal conductivity indicating the heat insulation performance of the vacuum heat insulating material 50 obtained in this way was measured by the same method as in Example 1, the initial value was 0.0022 (W / m · K), the equivalent of 5 years. The later thermal conductivity value was 0.0079 (W / m · K). Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

  In the sixth example, polybutylene terephthalate (PBT) was used for the heat-welded layer 58 in the outer packaging material film configuration shown in FIG. 2 for the purpose of improving heat resistance and enhancing gas barrier properties. Polybutylene terephthalate (PBT) has a higher melting point than unstretched polypropylene film (CPP), and can improve heat resistance. In accordance with this, polyethylene terephthalate (PET) having a melting point higher than that of the polyamide film (ONY) was also used for the surface protective layer 55.

Since polybutylene terephthalate (PBT) needs to be heated to about 200 to 220 ° C. in order to ensure the welding strength of the heat-welded portion, the surface protective layer 55 is made of polyethylene terephthalate (PET) and the first gas barrier layer 56. Was deposited on a polyamide film (ONY) with a thickness of 400 to 500 mm. As the adsorbent 53, a hydrophobic synthetic zeolite having an average pore diameter of 6 mm or more and a hydrophilic synthetic zeolite having an average pore diameter of 9 mm were used as in Example 3. Other conditions were the same as in Example 1.

  The heat conductivity indicating the heat insulating performance of the vacuum heat insulating material 50 obtained in this manner was measured in the same manner as in Example 1. As a result, the initial value was 0.0023 (W / m · K), after 5 years. The thermal conductivity value of was good at 0.0053 (W / m · K). Further, there was no particular change in the appearance of the vacuum heat insulating material 50.

(Comparative Example 1)
The vacuum heat insulating material 50 was produced by the same method as Example 1 for performance comparison. In the vacuum heat insulating material 50 shown in FIG. 1, the film of the outer packaging material 52 was compared as a configuration generally used for refrigerator applications. In FIG. 2, the surface protective layer 55 is a polyamide film (ONY), the first gas barrier layer 56 is polyethylene terephthalate (PET), and the second gas barrier layer 57 is an aluminum-containing aluminum foil (AL) having a thickness of 6 μm. 58 is an outer packaging material 52 using high-density polyethylene, and the adsorbent 53 is hydrophilic synthetic zeolite. Other conditions were the same as in Example 1.

The heat conductivity indicating the heat insulating property of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.000020 (W / m · K) after 5 years. The thermal conductivity value of was 0.00098 (W / m · K), indicating a large degree of deterioration. Moreover, it was observed that the heat welding layer 58 is in a lightly welded state as an external change of the vacuum heat insulating material 50.

(Comparative Example 2)
As a comparative example 2, a vacuum heat insulating material 50 was produced in the same manner as in the comparative example 1. In the vacuum heat insulating material 50 shown in FIG. 1, the structure generally used for the refrigerator use was compared as the film which strengthened the gas barrier property of the outer packaging material 52, and reduced the heat bridge. In FIG. 2, the surface protective layer 55 is made of polyamide film (ONY), the first gas barrier layer 56 is made of polyethylene terephthalate (PET), and aluminum is deposited in a thickness of 400 to 500 mm. The second gas barrier layer 57 Was formed by depositing aluminum in a thickness of 400 to 500 mm using an ethylene vinyl alcohol copolymer resin film as a base material, and high-density polyethylene was used as the heat welding layer 58. As the adsorbent 53, hydrophilic synthetic zeolite was used. Other conditions were the same as in Example 1.

The heat conductivity indicating the heat insulating property of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.0019 (W / m · K), after 5 years. The thermal conductivity value was 0.0152 (W / m · K), and the degree of deterioration was large. Further, as an external change of the vacuum heat insulating material 50, it was observed that the heat-welded layer 58 was lightly welded as in Comparative Example 1.

(Comparative Example 3)
As Comparative Example 3, the vacuum heat insulating material 50 shown in FIG. 1 was the same as Comparative Example 1 except that the heat-welding layer 58 of the outer packaging material 52 was an unstretched polypropylene film.

The heat conductivity indicating the heat insulating property of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.0026 (W / m · K), after 5 years. The thermal conductivity value was 0.0109 (W / m · K), indicating a large degree of deterioration. In addition, the external appearance change of the vacuum heat insulating material 50 was not observed in particular.

(Comparative Example 4)
As Comparative Example 4, in the configuration of Example 1, except that the resin film 56a of the first gas barrier layer 56 and the metal vapor deposition layer 56b are reversed and the metal vapor deposition layer 56b is on the surface protection 55 layer side. Same as above.

  The heat conductivity indicating the heat insulating performance of the vacuum heat insulating material 50 thus obtained was measured in the same manner as in Example 1. As a result, the initial value was 0.0021 (W / m · K) after 5 years. The thermal conductivity value of the sample was 0.0074 (W / m · K), and the degree of deterioration was greater than that of Example 1. In addition, the external appearance change of the vacuum heat insulating material 50 was not observed in particular.

  Here, the relationship between Example 5 and Comparative Example 4 will be considered. As described above, the thermal conductivities of both examples are 0.0022 (W / m · K) and 0.0021 (W / m · K) as initial values, respectively, and are 0. 0079 (W / m · K), 0.0074 (W / m · K). That is, Example 5 was inferior in thermal conductivity to Comparative Example 4.

  By the way, it is known that there are two main modes of heat conduction in the vacuum heat insulating material. The first mode is heat conduction through the core material 51 inside the outer packaging material 52, and the second mode is heat conduction mainly through the metal layer in the outer packaging material 52. This second aspect is called a heat bridge. It is well known that the influence of the heat bridge is large in the overall heat conduction of the vacuum heat insulating material. Therefore, the heat insulation performance as the whole vacuum heat insulating material can be improved by reducing the heat bridge.

  In addition, due to its nature, the influence of the heat bridge becomes larger as the metal layer in the outer packaging material 52 becomes thicker, and when the ear portion of the outer packaging material 52 is bent as shown by the broken line in FIG. It is easy to increase the influence of the heat bridge.

In Examples 1 to 6 and Comparative Examples 1 to 4, the thermal conductivity was measured without bending the ear 52a as shown in FIG. When the configurations of Example 5 and Comparative Example 4 are compared, Example 5 has a configuration in which a resin layer is interposed between aluminum deposition layers, compared to Comparative Example 4 having a metal layer made of aluminum foil. That is, the measured values have substantially the same thermal conductivity, but it is considered that the ratio of the influence of the heat bridge (the second aspect) is greatly different.

  In general, the thickness of the metal foil layer is on the order of micrometers, whereas the thickness of the metal vapor deposition layer is on the order of angstroms, and the influence of heat conduction by the heat bridge is greatly different. From these considerations, when the vacuum heat insulating material having the configuration described in Example 5 is used by bending the ear portion 52a, it is more advantageous than the configurations of the comparative examples including the comparative example 4.

  Therefore, in an actual usage mode, when the ear portion is bent and used, for example, when used for a heat insulating box of a refrigerator or when used for a hot water supply device (a heat pump water heater or an electric pot) described later, The configuration is more advantageous than the configuration of Comparative Example 4.

  As described above, comparing Examples 1 to 6 and Comparative Examples 1 to 4 can provide a vacuum heat insulating material excellent in long-term reliability by using an outer packaging material obtained by bonding a metal vapor deposition layer and a metal foil layer. I found out that Moreover, when using the outer packaging material which gave the resin coating between the metal vapor deposition layers, it turned out that a high heat insulation performance can be ensured when bending and using an ear | edge part. It was also found that long-term reliability of the vacuum heat insulating material can be improved by using a hydrophobic synthetic zeolite as an adsorbent. In addition, no deterioration was observed in the adhesive that bonds the two metal layers.

  Next, a hot water supply device using a vacuum heat insulating material will be described.

  Table 2 shows an outline of Examples 7 to 9 in which a vacuum heat insulating material is applied to the heat pump water heater. In each example, the amount of heat leakage was measured using a vacuum heat insulating material having the same configuration, and comparison and examination were performed. Details will be described below.

  An example of studying application of a vacuum heat insulating material to a heat pump water heater will be described with reference to FIGS. FIG. 5 shows a hot water storage tank 200 and a refrigerant-to-heat exchanger 201 of a heat pump water heater. FIG. 6 shows a section AA in FIG.

  In the seventh embodiment, vacuum heat insulating materials 301 and 302 are provided on the outer periphery of the hot water storage tank 200 shown in FIG. 5 and on the outer periphery of the refrigerant-to-heat exchanger 201 including the condenser 201a and the feed water heat transfer tube 201b. As the vacuum heat insulating materials 301 and 302, vacuum heat insulating materials having the same specifications as those in the third embodiment are used.

  In Example 7, as shown in FIG. 6A, the vacuum heat insulating material 301 is bent and attached along the outer peripheral arc of the hot water storage tank 200, and the end portions 310 of the vacuum heat insulating material 301 in the bending direction are connected to each other. Arranged to overlap. Moreover, the vacuum heat insulating material 302 was bent and affixed along the circular arc of the outer periphery of the refrigerant | coolant anti-heat exchanger 201, and it arrange | positioned so that the edge parts of the bending direction length of the vacuum heat insulating material 301 may overlap. At this time, the shape of the end portion 310 may be a stepped shape in the plate thickness direction as shown in FIG. 6D so that the thickness of the overlapping portion between the end portions 310 does not protrude.

  The amount of heat leakage in the hot water storage tank section in this example was compared with a heat insulating material (glass wool alone or phenol foam, etc .; hereinafter referred to as “conventional heat insulating material”) generally used for building materials such as houses. As a result, a 29% heat leakage reduction effect was obtained.

  In an eighth embodiment of the present invention, vacuum heat insulating materials 301 to 304 having the same specifications as those of the third embodiment are provided on the outer periphery of the hot water storage tank 200 shown in FIG. As shown in FIG. 6 (b), the vacuum heat insulating material 301 is bent and pasted along the arc of the outer periphery of the hot water storage tank 200 so that the ends of the vacuum heat insulating material 301 in the bending direction do not overlap each other. Arranged. On this vacuum heat insulating material 301, another vacuum heat insulating material 303 was attached to the vacuum heat insulating material 301 in a state rotated 180 ° in the circumferential direction by the same method.

  Further, the vacuum heat insulating material 302 was bent and pasted along the outer peripheral arc of the refrigerant-to-heat exchanger 201, and arranged so that the ends of the vacuum heat insulating material 301 in the bending direction did not overlap each other. On this vacuum heat insulating material 302, another vacuum heat insulating material 304 was attached to the vacuum heat insulating material 302 in a state rotated 180 ° in the circumferential direction by the same method. At this time, the shape of the end portion 310 of each vacuum heat insulating material may be a stepped shape in the plate thickness direction as shown in FIG. 6D so that the thickness of the overlapping portion between the end portions 310 does not protrude.

  The amount of heat leakage in the hot water storage tank section in this example was 35% lower than when a conventional heat insulating material was used.

  As Example 9, vacuum heat insulating materials 301 and 302 having the same specifications as those of Example 3 are provided on the outer periphery of the hot water storage tank 200 shown in FIG. 5, the outer periphery of the refrigerant-to-heat exchanger 201 including the condenser 201a and the feed water heat transfer pipe 201b, as shown in FIG. As shown in c), the vacuum heat insulating material 301 was bent and attached along the arc of the outer periphery of the hot water storage tank 200, and the ends of the vacuum heat insulating material 301 in the bending direction were arranged so as not to overlap each other. Further, the vacuum heat insulating material 302 was bent and pasted along the outer peripheral arc of the refrigerant-to-heat exchanger 201, and arranged so that the ends of the vacuum heat insulating material 301 in the bending direction did not overlap each other.

  The amount of heat leakage in the hot water storage tank portion in this example was 22% lower than when a conventional heat insulating material was used.

In consideration of the above Examples 7 to 9, it was confirmed that all of them could exhibit sufficient heat insulation performance even in a high temperature environment. Moreover, compared with Examples 7 and 8, Example 9 resulted in a low heat leakage reduction effect. From these results,
(1) The vacuum heat insulating material of this example can sufficiently withstand use even in a high temperature environment reaching 80 ° C. or more (Examples 7 to 9).
(2) The heat insulation performance is improved when the heat insulation layer is formed thick (comparison between Example 8 and Example 9).
(3) When the end portions of the vacuum heat insulating material to be used are arranged so as to overlap each other, the heat insulating performance is improved (comparison between Example 7 and Example 9).
(4) It is also effective to use a stepped vacuum heat insulating material (Example 8).
(1) to (4) were found.

  Next, a further example of a hot water supply device using a vacuum heat insulating material will be described.

  Table 3 shows an outline of Examples 10 and 11 in which a vacuum heat insulating material is applied to the electric pot. In each example, the amount of heat leakage was measured using a vacuum heat insulating material having the same configuration, and comparison and examination were performed. Details will be described below.

  Examples of studying application of the vacuum heat insulating material to the electric pot according to the present invention will be described with reference to FIGS. FIG. 7 shows an electric pot 400 that includes a water storage container 401 and a lid portion 402. FIG. 8 shows a section BB in FIG. In the tenth embodiment of the present invention, in FIG. 7, a vacuum heat insulating material 501 having the same specification as that of the fifth embodiment is attached to the outer periphery of the water storage container 401 as shown in FIG. The power retention time was compared by the time until the power was turned off later and the hot water temperature cooled to 80 ° C. The vacuum heat insulating material 501 was bent and attached along the outer peripheral arc of the water storage container 401, and the vacuum heat insulating material 501 was arranged so that the ends of the bending direction length overlap each other. Moreover, since the size of the applicable vacuum heat insulating material 503 is small as heat insulation reinforcement | strengthening of the cover part 402, since the influence of the heat bridge of an outer packaging material becomes large, it has arrange | positioned without bending an ear | edge part.

  The heat retention time in this example was 217 when the case where there was no vacuum heat insulating material was 100, and it was confirmed that the heat insulating performance was improved.

  As Example 11, in FIG. 7, the vacuum heat insulating material 501 having the same specifications as in Example 5 is arranged on the outer periphery of the water storage container 401, and the vacuum heat insulating material 501 is arranged on the outer periphery of the water storage container 401 as shown in FIG. Bending along and pasting, the end portions of the vacuum heat insulating material 501 in the bending direction were arranged so as not to overlap each other.

  The heat retention time in this example was 193 when the case where there was no vacuum heat insulating material was 100, and the effect was about 11% lower than that in Example 10 due to the heat bridge effect at the end of the vacuum heat insulating material.

  As described above, the vacuum heat insulating material according to the present invention can suppress the deterioration of the heat insulating performance even in a high temperature region of 80 ° C. or higher, and maintains the heat insulating performance for a long time. From each of the above examples, it was confirmed that there was no problem in use up to a high temperature range of at least about 110 ° C.

  As a result, the field of application capable of exhibiting a heat insulating effect is not limited to the hot water supply equipment described in the embodiments, with the upper limit being the above temperature range, as well as refrigerators, cold boxes, bathtubs, vehicles such as cars and trains, and houses , It can be widely applied to equipment and facilities that require heat insulation, such as housing equipment.

Also, as the first gas barrier layer, any one of a polyamide resin film (PA), an ethylene vinyl alcohol copolymer resin film (EVOH), a polyvinyl alcohol resin film (PVA), and a polyethylene terephthalate resin film (PET) is used. As the base material, a metal film of either aluminum (AL) or stainless steel (SUS) is used on one side, and as the second gas barrier layer, aluminum foil (AL), stainless steel foil (SUS), iron foil is used. A laminate film in which any of the metal foils of (Fe) is used and the metal layers of the first and second gas barrier layers are bonded to each other, and a non-stretched polypropylene resin film (CPP) or poly (polypropylene resin film) is used as a heat welding layer. One of the butylene terephthalate resin film (PBT) In addition, since the surface protective layer has a multilayer laminate structure with a resin film having a melting point higher than that of the heat-welded layer, the metal film directly closes the pinhole peculiar to the metal foil. Gas and moisture can be prevented from entering.

  This effect can be maintained even when the resin coating layer is sandwiched between two metallized films, especially in the case of vacuum insulation materials that are used with bent ears, with high gas barrier properties and high heat insulation performance by reducing heat bridges. Can be maintained over a long period of time.

Sectional drawing of a vacuum heat insulating material. Expansion explanatory drawing of an outer packaging material film. Expansion explanatory drawing of an outer packaging material film. Sectional drawing which shows the vacuum heat insulating material which measures heat conductivity. Explanatory drawing of the hot water storage tank part of the heat pump water heater provided with the vacuum heat insulating material. AA sectional drawing of FIG. Explanatory drawing of the electric pot provided with the vacuum heat insulating material. BB sectional drawing of FIG. Sectional drawing of the vacuum heat insulating material arrangement | positioning part of the conventional vacuum heat insulating material application product. Sectional drawing which shows the general structure of the high temperature side film in FIG. Sectional drawing which shows the general structure of the low temperature side film in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 ... Vacuum heat insulating material, 52 ... Outer packaging material, 53 ... Adsorbent, 56 ... 1st gas barrier layer, 56a ... Resin film, 56b ... Metal vapor deposition layer, 57, 59 ... 2nd gas barrier layer, 58 ... Thermal welding layer , 59a ... resin film, 59b ... layer consisting of a metal vapor deposition layer and a resin coating layer, 200 ... hot water storage tank, 201 ... heat exchanger, 301-304, 501,502 ... vacuum insulation, 310 ... vacuum insulation end, 400 ... electric pot, 401 ... water storage container, 402 ... lid part.

Claims (9)

Vacuum insulation comprising: a core material made of an inorganic fiber aggregate; an outer packaging material having a surface protective layer, a gas barrier layer, and a heat welding layer; and an adsorbent that adsorbs moisture and gas components of the core material and the outer packaging material. In the material,
The gas barrier layer of the outer packaging material is laminated so that the metal surfaces of at least two metal layers face each other, and a first gas barrier layer and a second gas barrier layer are used, and a resin film having a melting point of 150 ° C. or more is used as a heat welding layer Vacuum insulation. A core material made of an inorganic fiber aggregate; an outer packaging material having a surface protective layer, a gas barrier layer, and a heat-welded layer; an inner packaging material that holds the core material in a compressed state in the thickness direction; and the core material, outer packaging material, and inner packaging In vacuum insulation material with adsorbent that adsorbs moisture and gas components of the material,
A gas barrier layer of the outer packaging material has first and second gas barrier layers having two metal layers sandwiching an adhesive layer;
The first gas barrier layer is a film in which a metal film is formed on one side of a resin film substrate,
The second gas barrier layer is either a metal foil or a film in which a metal film is formed on one surface of a resin film substrate, and the formed metal film is coated with a resin,
The gas barrier layer of the outer packaging material is a laminate of resin film layer / metal film / adhesive layer / metal foil or a combination of resin film layer / metal film / resin coating layer / adhesive layer / metal film / resin film layer,
A resin film having a melting point of 150 ° C. or higher is used as the heat welding layer located on the core material side from the innermost layer of the gas barrier layer, and the surface protective layer located outside the outermost layer of the gas barrier layer is from the heat welding layer. Also use a resin film with a high melting point,
The core material does not contain a binder and has resilience in the thickness direction, and the adsorbent is stored in a storage section provided by being cut obliquely with respect to the surface of the core material or the thickness direction, and the opening of the storage section Vacuum heat insulating material with a structure that can be overlapped and narrowed.   The vacuum heat insulating material according to claim 1 or 2, wherein the adsorbent includes at least a hydrophobic adsorbent.   The gas barrier layer is any one of a polyamide resin film (ONY), an ethylene vinyl alcohol copolymer resin film (EVOH), a polyvinyl alcohol resin film (PVA), and a polyethylene terephthalate resin film (PET) as the first gas barrier layer. As a second gas barrier layer, an aluminum foil (AL) or stainless steel foil is used in which a resin film is used as a base and a metal film of either aluminum (AL) or stainless steel (SUS) is formed on one side. (SUS) or iron foil (Fe), using a metal foil, the metal parts of the first and second gas barrier layers sandwich the adhesive layer, and a laminated film is bonded to face each other. Non-stretched polypropylene resin film (CPP) or polybutylene as the heat welding layer to be combined Either of the terephthalate resin film (PBT), and the surface protective layer is an outer packaging material made of a multilayer laminate film in which the melting point is higher than that of the heat welding layer. The vacuum insulation material according to crab. The gas barrier layer includes first and second gas barrier layers, and the first gas barrier layer includes a polyamide resin film (ONY), an ethylene vinyl alcohol copolymer resin film (EVOH), and a polyvinyl alcohol resin film (PVA). , A polyethylene terephthalate resin film (PET) resin film as a base material and a metal film of either aluminum (AL) or stainless steel (SUS) formed on one side thereof, and the second gas barrier. As a layer, an ethylene vinyl alcohol copolymer resin film (EVOH), a polyvinyl alcohol resin film (PVA), or a polyethylene terephthalate resin film (PET) is used as a base material, and aluminum (AL), stainless steel is used on one side. (SUS) A gas barrier resin-based coating layer is provided on one of the metal films, and the metal portion of the first gas barrier layer and the resin-based coating layer of the second gas barrier layer sandwich the adhesive layer, and A laminate film facing each other and used as a heat-welding layer to be combined therewith is an unstretched polypropylene resin film (CPP) or a polybutylene terephthalate resin film (PBT). The vacuum heat insulating material in any one of Claims 1-3 using the outer packaging material which consists of a multilayer laminate film made into the resin film whose melting | fusing point is higher than a heat welding layer.   The adhesive according to claim 1, wherein a thermosetting resin or an adhesive having a melting point higher than that of the heat welding layer is used as an adhesive for adhering between the first gas barrier layer and the second gas barrier layer. The vacuum heat insulating material in any one. The hydrophobic adsorbent In SiO ₂ / Al ₂ O ₃ ratio of 20 or more, and the vacuum heat insulating material according to claim 1 which is a high-silica zeolite is non-flammable.   In a hot water supply apparatus such as a heat pump type provided with at least a hot water storage tank, the vacuum heat insulating material according to any one of claims 1 to 7 is arranged in an arc shape along the outer periphery of the hot water storage tank. A hot water supply apparatus characterized in that the heat insulation at the end is doubled. In an electric water heater having at least a water heating function and a heat retaining function, and comprising an outer container, a water storage container, and a lid part, the vacuum heat insulating material according to any one of claims 1 to 7, the outer periphery of the water storage container The electric water heater is arranged so as to be bent along the end of the vacuum heat insulating material in the bending direction.

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