JP2001231681A - Electric water heater - Google Patents

Abstract

(57) [Problem] To provide an electric water heater that can maintain a higher heat insulating property without deterioration at a high temperature of about 100 ° C. without destruction of a deposited layer. SOLUTION: A heater 1 for heating water in a water storage container 2 is provided.
3, a tapping path for allowing water to flow out, and a vacuum heat insulating material 20. The vacuum heat insulating material 20 is a laminate film 24 including a gas barrier layer 28, a protective layer 29, and a seal layer 25.
The gas barrier layer 28 is an electric water heater composed of a vapor-deposited film obtained by vapor-depositing at least a copolymer resin film base of ethylene and vinyl alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater for keeping and supplying hot water for drinking at home or office.

[0002]

2. Description of the Related Art When an electric water heater is filled with water and connected to a power source, the water is boiled. However, the water needs to be kept at a substantially constant temperature for a long time. Therefore, generally, the periphery of the water storage container in the electric water heater is covered with various heat insulating materials.
Examples of the heat insulating material include an inorganic heat insulating material such as glass wool and a heat insulating material using a metal reflector. Furthermore, a heat insulating core material is enclosed in a packaging material made of an aluminum foil as a gas barrier layer or a laminated film using a vapor deposition layer obtained by performing aluminum vapor deposition using polyethylene terephthalate (hereinafter referred to as PET) as a base material. There are vacuum insulation materials that are evacuated.

[0003]

However, a heat insulating material such as glass wool has a problem that thermal durability is excellent but heat insulating performance is low. A vacuum insulation material that uses a metal foil such as an aluminum foil as the gas barrier layer in a vacuum insulation material that has been evacuated to the inside of the packaging material has good heat insulation performance inside the packaging material, but has a calorific value transmitted through the metal foil that is the gas barrier layer. Is very large, so that the heat insulation of the vacuum heat insulating material as a whole is not sufficiently good. In order to suppress the amount of heat transmitted through the metal foil, there is a vacuum heat insulating material using a vapor deposition layer such as aluminum vapor deposition as a gas barrier layer. This is because PET is used as a deposition base material, but PET has poor thermal dimensional stability, and the thickness of the deposition layer is very thin. ,
There has been a problem that the gas barrier property is reduced, the vacuum cannot be maintained, the heat insulation performance is deteriorated, and the electric power for maintaining the electric water heater becomes large.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and the use of a copolymer resin film of ethylene and vinyl alcohol as a vapor deposition base material enables the use of a resin film of about 100.degree. The present invention realizes an electric water heater that can maintain a higher heat insulating property without deterioration at a high temperature.

According to the above invention, the gas barrier layer is not broken at a temperature of about 100 ° C. by using the copolymer resin film of ethylene and vinyl alcohol as the vapor deposition base material. Since the copolymer resin film with alcohol itself has a high gas barrier property, a vacuum state can be maintained, so that the heat insulating property does not decrease for a long time. In addition, by using a vapor deposition layer instead of metal foil as the gas barrier layer, it is possible to suppress the heat flowing from the high-temperature portion through the gas barrier layer itself, improve the heat insulating performance of the entire vacuum heat insulating material, and improve the electric water heater. Insulation power can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a water storage container, a heater for heating water in the water storage container, a hot water outlet path for discharging water, and a vacuum heat insulating material. The vacuum heat insulating material is composed of a laminated film comprising a gas barrier layer, a protective layer, and a seal layer, and a heat insulating core material is vacuum-sealed, and the gas barrier layer is formed of at least ethylene and vinyl alcohol. An electric water heater consisting of a vapor-deposited film obtained by vapor-depositing a polymer resin film substrate, and having a heat conductivity of 25 as a heat insulating material.
About 0.0035 (kcal / m.h..degree. C.) at 25.degree. C. compared with an electric water heater using glass wool at about 25.degree.
An electric water heater using a vacuum heat insulating material of 6 (kcal / m · h · ° C.) can keep the heat retention power lower.
In addition, an electric water heater using a vapor-deposited layer as a gas barrier layer has a small amount of heat leaking from an end face along the gas barrier layer itself, and thus is compared with an electric water heater in which a vacuum heat insulating material using a metal foil is disposed as a gas barrier layer. Therefore, the heat retention power can be further reduced. In addition, when a copolymer resin film of ethylene and vinyl alcohol is used as a vapor deposition substrate, the vapor deposition layer is not destroyed even at a high temperature of 100 ° C., so that it is more thermally durable than a conventional vacuum insulation material using PET as a vapor deposition substrate. Thus, an electric water heater can be realized in which the heat retention power is kept low for a long time.

According to a second aspect of the present invention, the gas barrier layer is formed by laminating one or a plurality of vapor-deposited films laminated such that the vapor-deposited surfaces of the vapor-deposited films obtained by vapor-depositing the resin film base material face each other. The electric water heater according to the first aspect of the present invention is a laminated film, and can further reduce the heat retention power as compared with an electric water heater in which a vacuum heat insulating material using a metal foil is disposed in a gas barrier layer. In addition, a small hole called a pinhole exists in the vapor deposition layer, through which gas enters the inside of the vacuum heat insulating material.By attaching the vapor deposition surfaces to each other, the pinholes of the vapor deposition layer complement each other, Since the barrier property can be greatly improved, the thermal durability can be improved as compared with a conventional vacuum heat insulating material using PET as a vapor deposition base material, and an electric water heater having a low heat retention power for a long time can be realized.

According to a third aspect of the present invention, the gas barrier layer comprises a vapor-deposited film obtained by vapor-depositing a copolymer resin film substrate of ethylene and vinyl alcohol and a vapor-deposited film obtained by vapor-depositing a heat-resistant resin film substrate. A laminated film in which a film and a vapor-deposited surface are laminated to face each other, and a vapor-deposited film obtained by vapor-depositing the copolymer resin film of ethylene and vinyl alcohol is disposed on a heat insulating core material side. Item 2 is the electric water heater described in Item 2, which can further reduce the heat retention power as compared with an electric water heater in which a vacuum heat insulating material using metal foil is disposed in the gas barrier layer. In addition, since the heat-resistant resin film substrate is used on the outer layer side, the copolymer resin film of ethylene and vinyl alcohol is not directly exposed to oxygen, and oxidation deterioration is suppressed, so that the vapor deposition layer is destroyed. In addition, the thermal durability can be improved as compared with a conventional vacuum heat insulating material using PET as a vapor deposition base material, and an electric water heater in which the heat retention power is suppressed for a long time can be realized.

Further, the invention according to claim 4 is characterized in that a vapor-deposited film obtained by vapor-depositing a heat-resistant resin film substrate is provided between the gas barrier layer and the seal layer. The electric water heater described above can further reduce the heat retention power as compared with an electric water heater in which a vacuum heat insulating material using a metal foil is disposed in a gas barrier layer. In addition, when a copolymer resin film of ethylene and vinyl alcohol is used as a deposition base material, the deposition layer is not destroyed even at a high temperature of 100 ° C. Thermal durability can be further improved as compared with a water heater. Further, since the copolymer resin film of ethylene and vinyl alcohol is a film having high hygroscopicity, when exposed to a high temperature, the absorbed moisture is generated as water vapor. Here, by providing a gas barrier layer between the copolymer resin film of ethylene and vinyl alcohol and the seal layer, generated steam flows into the core material side, and prevents an increase in the internal pressure of the vacuum heat insulating material. It is possible to realize an electric water heater that keeps the heat retention power small for a long time.

According to a fifth aspect of the present invention, there is provided an electric water heater according to any one of the first to fourth aspects, wherein vapor deposition is performed on both surfaces of a copolymer resin film substrate of ethylene and vinyl alcohol. Therefore, compared to an electric water heater in which a vacuum heat insulating material using a metal foil is disposed in the gas barrier layer, the heat retention power can be further reduced. In addition, when a copolymer resin film of ethylene and vinyl alcohol is used as a deposition base material, the deposition layer is not destroyed even at a high temperature of 100 ° C. Thermal durability can be further improved as compared with a water heater. Further, since the copolymer resin film of ethylene and vinyl alcohol is a film having high hygroscopicity, when exposed to a high temperature, the absorbed moisture is generated as water vapor. Here, by providing a gas barrier layer between the copolymer resin film of ethylene and vinyl alcohol and the seal layer, generated steam flows into the core material side, and prevents an increase in the internal pressure of the vacuum heat insulating material. It is possible to realize an electric water heater that keeps the heat retention power small for a long time.

According to a sixth aspect of the present invention, the heat-resistant resin film substrate contains at least one of polyethylene terephthalate, polyethylene naphthalate, polyphenyl sulfide and polyimide. Because of using an electric water heater and using a heat-resistant resin film, the thermal durability can be improved compared with the conventional vacuum insulation material using PET as a vapor deposition base material, and the heat retention power for a long time has been reduced. An electric water heater can be realized.

According to a seventh aspect of the present invention, there is provided the method as set forth in any one of the first to fifth aspects, wherein the deposit formed by depositing the copolymer resin film base contains at least one of aluminum, alumina and silica. According to the electric water heater described in the item 1, it is possible to further reduce the heat retention power as compared with an electric water heater in which a vacuum heat insulating material using a metal foil is disposed in a gas barrier layer.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a main body (hereinafter, simply referred to as a main body) of an electric water heater main body, which has a water storage container 2 (hereinafter, simply referred to as a container 2) having an inner diameter of 184 mm and a depth of 200 mm for storing water therein. Reference numeral 3 denotes an inner stopper for sealing the mouth of the container 2. Reference numeral 4 denotes an upper cover that covers the upper part of the main body 1 so as to be openable and closable. Reference numeral 5 denotes a vapor passage provided in the upper lid, one end of which passes through the inner plug 3 and communicates with the inside of the container 2, and the other end communicates with the atmosphere. 6
Is a water leakage prevention valve, which is disposed in the steam passage 5, and shuts off the steam passage 5 when the vehicle falls down. Here, the steam passage 5 is complicatedly bent.

Accordingly, when the pressure inside the container 2 becomes higher than the atmospheric pressure such as when the water in the container 2 boils,
Although the steam is discharged to the outside of the main body through the steam passage 5, the outside air and the air between the water surface in the container 2 and the upper lid 4 (hereinafter referred to as inside air) are not easily mixed.

Reference numeral 7 denotes a motor provided at the bottom between the main body 1 and the container 2, and 8 denotes a pump driven by the motor 7, and its suction port 9 communicates with the bottom of the container 2. Reference numeral 10 denotes a discharge port of the pump 8, which communicates with 11 tapping pipes constituting a part of the tapping path. Reference numeral 12 denotes a tap hole from which the tap water flows out of the electric water heater. Reference numeral 13 denotes a heater for heating, which has a donut shape and has a central portion removed, and is attached to the lower portion of the container 2. A start switch 15 for driving the motor 7 has a variable resistor, and has a push button 1
6 is operated via the rod 17 by the push operation switch. Reference numeral 18 denotes a compression spring.
Are always urged to push the rod 17 upward. Reference numeral 19 denotes a control device which receives a signal from the temperature detector 14 and controls the heater 13 and the like. Reference numeral 20 denotes a vacuum heat insulating material wound on the side surface of the container 2, and has a role of preventing heat of the container 2 from escaping from the side surface of the main body 1.

Here, the used vacuum heat insulating material 20 will be described with reference to the drawings. FIG. 2 shows a sectional view of the vacuum heat insulating material 20.
Reference numeral 22 denotes a heat insulating core material of a vacuum heat insulating material (referred to as a core material in this embodiment). The core material 22 is contained in the inner bag 23. Inner bag 23 containing core material 22 is further laminated film 2
4 are housed in a vacuum state in a bag in which the gas barrier layer 4 is bonded to the gas barrier layer 2 composed of a sealing layer 25, a resin film substrate 26, and a vapor deposition layer 27.
8 and a protective layer 29. The core material 22 has a low thermal conductivity, and the holes and gaps need to communicate with the outside. As the core material 22, an organic or inorganic material can be used, but when used at a high temperature such as an electric water heater, a material that does not generate gas is required. Materials that do not generate gas include pearlite and shirasu balloon, and in this embodiment, synthetic silica was used as the core material 22. Since the particles of synthetic silica are very fine, the thermal conductivity of the particles is very low. Further, if the pressure is 10 torr or less, the material exhibits a very small thermal conductivity regardless of the pressure, and thus is a material very suitable under a large condition of air molecular motion at a high temperature.

The seal layer 25 has a role of bonding the laminated films 24 to each other and maintaining an internal vacuum. The sealing layer must be easily heat-sealed,
Usually, polyethylene, high-density polyethylene, polyacrylonitrile, polypropylene and the like are used. In this embodiment, unstretched polypropylene having a high degree of crystallinity with a homopolymer is used for the seal layer 25 at a high temperature of about 100 ° C. without deterioration for a long time. I have.

The gas barrier layer 28 has a function of blocking gas passing through the laminate film 24 and maintaining a vacuum inside the vacuum heat insulating material. The pressure inside the vacuum heat insulating material (hereinafter referred to as the internal pressure) is usually 30 torr or less, and as the internal pressure increases, the thermal conductivity of the vacuum heat insulating material 20 also increases, and the heat insulating performance deteriorates. Especially 30 to
The heat retention power of the electric water heater also starts to increase from around rr. Therefore, a layer capable of blocking gas at a temperature of about 100 ° C. for a long time is required. Therefore, an aluminum foil having a thickness of 6 to 10 μm is usually used for the gas barrier layer 28. However, since aluminum is a good conductor of heat, the amount of heat leaking along the surface of the vacuum heat insulating material increases in proportion to the thickness of aluminum, so that the heat retention power of the electric water heater increases.

Therefore, in this embodiment, the gas barrier layer 2
8, a vapor-deposited layer 27 obtained by vapor-depositing a resin film substrate 26 was used. As the resin film substrate 26, a polyester film such as polyethylene terephthalate (hereinafter, referred to as PET) or an amide film such as nylon is used. In particular, a polyvinyl alcohol film (hereinafter, referred to as P) is used.
VA), an ethylene-vinyl alcohol copolymer resin film (hereinafter, referred to as EVOH), or a polyethylene naphthalate film (hereinafter, referred to as PEN), when the temperature of the electric water heater is kept at about 100 ° C. for a long time. Since the vapor-deposited layer does not deteriorate and the heat resistance of the vacuum heat insulating material can be greatly improved, it is possible to realize an electric water heater that does not deteriorate for a long time and has a small heat retaining power.

As the EVOH, EVAL XL (manufactured by Kuraray Co., Ltd.) can be mentioned. This EVOH is a resin that is easily oxidized and degraded at high temperatures, but in a state of low oxygen, the deposited layer formed by vapor deposition on the EVOH is stable for a long period of time without deterioration, and the EVOH itself has a high gas barrier property. Therefore, the gas barrier layer 28 has at least E
The use of a vapor-deposited VOH makes it possible to realize an electric water heater having a low heat-retention power amount that does not deteriorate for a long time.

A heat-resistant resin film base material such as PEN, which is subjected to vapor deposition, is used as a gas barrier layer by EVO.
Since the EVOH does not directly contact oxygen and suppresses oxidative deterioration by being used for the outer layer than H, the thermal durability can be further improved without destroying the deposited layer, and the heat retention power for a long time It is possible to realize an electric water heater with a small size. Further, this heat-resistant resin film also serves as a protective layer. In addition, since EVOH is a highly hygroscopic film, when it is exposed to high temperature, it absorbs the absorbed moisture as water vapor. Therefore, if there is no gas barrier layer between the EVOH and the seal layer, the generated water vapor is a core. It flows into the material side and raises the internal pressure of the vacuum heat insulating material, deteriorating the heat insulating performance. Therefore, by providing the gas barrier layer between the EVOH and the seal layer, it is possible to prevent an increase in the internal pressure of the vacuum heat insulating material.

The vapor deposition layer 27 is formed by vapor deposition of a metal such as aluminum or aluminum oxide (hereinafter, referred to as aluminum oxide).
A material obtained by depositing a metal oxide such as alumina or silicon oxide (hereinafter, silica) is used. When a metal such as aluminum is used as the vapor deposition layer, the metal has ductility, so that even if the base material is bent, the vapor deposition layer is not broken, and the vacuum heat insulating material 20 is formed in a cylindrical shape so as to fit the container 2 well. Can be processed.

Further, the vapor-deposited layer 27 has a thermal conductivity smaller than that of aluminum having an average temperature of 300 K and a thermal conductivity of 273 (W / m · K), for example, nickel (90 W / m · K) at an average temperature of 300 K. K), titanium (20 W / m
The use of metals such as K), alumina (36 W / mK), and silica (1.4 W / mK) can reduce the amount of heat transmitted through the vacuum insulation material itself, further reducing the amount of heat insulation power The electric kettle can be realized.

As for the thickness of the vapor deposition layer, the thickness of one vapor deposition layer used in the present embodiment is about 0.01 to 1 μm, but the thickness of 0.01 to 1 μm corresponds to the ordinary vapor deposition layer. And other thicknesses are within the scope of the present invention. In addition, a small hole called a pinhole exists in the vapor deposition layer, through which gas enters the inside of the vacuum heat insulating material. As shown in FIG. Since the pinholes of the vacuum heat insulating material can be complemented with each other and the gas barrier properties of the vacuum heat insulating material can be greatly improved, an electric water heater having a low heat retention power for a long time can be realized. In this case, the outer resin film substrate also functions as a protective layer.

Since the vapor deposition layer 27 is a thin layer having a thickness of about 0.01 to 1 μm, it is very easily scratched, and if it is scratched, it cannot maintain a vacuum, does not function as a heat insulating material, and has no function as an electric water heater. The amount of heat retention increases. The protection layer 29 has a role of protecting the vapor deposition layer 27 so as not to cause such a case. The protective layer is not particularly limited as long as it is a resin film that does not deteriorate at a temperature of about 100 ° C. However, in consideration of the fact that the electric water heater is likely to be in contact with many other parts at the time of attachment or detachment at the time of attachment or removal, and is likely to be scratched. By arranging slippery nylon on the outermost layer, mounting can be performed smoothly and assembly performance is improved.

FIG. 4 is a plan view of the vacuum heat insulating material, which is a flat, rectangular shape. Numeral 32 is a portion containing the core material 22 and having a heat insulating property as a vacuum heat insulating material. Reference numeral 33 denotes a heat-sealed portion which does not include a core material because the heat-sealed portion has the adhesive portion 30 welded by the seal layer 25.
As shown in FIG. 5, the vacuum heat insulating material is used by folding the heat seal portion and winding it around the container 2.

Hereinafter, the operation of this embodiment will be described. When electricity is supplied after water is put into the water storage container 2, the water temperature in the container 2 is measured by the temperature detector 14, and the signal is sent to the control device 19.
And the control device starts to energize the heater 13. When the water in the container 2 boils, the energization of the heater 13 ends. Thereafter, in response to a signal from the temperature detector 14, the control device 19 controls the heater 13 so that the temperature of the container 2 becomes substantially constant. When tapping, the push button 16 is pressed. The motor 7 is operated, and the water in the container 2 is discharged by the pump 8 from the tap hole 12 to the outside of the electric water heater through the tap hole 11 and used. Hereinafter, experimental examples of heat insulating properties and thermal durability of various vacuum heat insulating materials will be described.

<Experimental Example 1> A vacuum heat insulating material in which the gas barrier layer is an aluminum foil (referred to as an aluminum foil in this experimental example), and the gas barrier layer is formed by depositing aluminum using PET as a resin film substrate. (In this experimental example, this is referred to as aluminum-deposited PET.) The gas barrier layer is EVO
H-deposited aluminum film using H as a resin film substrate (referred to as aluminum-deposited EVOH in this experimental example), and gas-deposited aluminum vapor-deposited gas barrier layer using PEN as a resin film substrate (in this experimental example, aluminum-deposited PEN)
The gas barrier layer was prepared by subjecting PEN to a resin film base material and performing silica vapor deposition (in this experimental example, referred to as silica-deposited PEN). Aluminum foil, aluminum deposition P
ET, aluminum-deposited EVOH, aluminum-deposited PEN, and silica-deposited PEN were wound around the container 2 so that the heat-sealed portion came to the outside of the cylinder as shown in FIG. And prepare an electric water heater having these,
Water was put into these electric kettles, and the heat retention power of each was measured. The temperature of the heat retaining water was 96.5 ° C., and the temperature of the atmosphere was 20 ° C. The measurement was performed after sufficient equilibrium was reached. From the experimental results, the heat retention power of various vacuum insulation materials is shown in (Table 1).

[0030]

[Table 1]

As described above, the gas barrier layer of the vacuum heat-insulating material using a resin film formed by vapor deposition can reduce the heat retention power as compared with the one using the aluminum foil. Thus, by using vapor deposition, which is thinner than aluminum foil, as the gas barrier layer, the amount of heat flowing through the gas barrier layer itself could be suppressed, and the heat insulating performance of the vacuum heat insulating material could be improved. In addition, as a deposited material, it is more preferable to use a metal oxide silica having a relatively low thermal conductivity than to use aluminum which is a metal having a relatively high thermal conductivity.
The amount of heat flowing along the gas barrier layer itself could be suppressed, and the heat insulating performance of the vacuum heat insulating material could be improved. Therefore, by using a vacuum heat insulating material that is obtained by depositing a resin film as a gas barrier layer, it is possible to realize an electric water heater that requires less heat retention power.

<Experimental Example 2> A thermostat at 100 ° C. and a vacuum heat insulating material of aluminum foil, aluminum-deposited PET, and aluminum-deposited EVOH were prepared. Further, in a vacuum heat insulating material, a gas barrier layer in which EVOH is used as a resin film base material and aluminum is deposited and a PEN is used as a resin film base material and aluminum is deposited are attached to each other on a vapor-deposited surface (this experimental example). (EVOHPEN aluminum vapor deposition), a gas barrier layer with EVOH as the resin film substrate and aluminum vapor deposition, and a PET with the resin film substrate as aluminum vapor deposition bonded together on the vapor deposition surfaces (this experiment) In the example, EVOHPET
Aluminum vapor deposition), a gas barrier layer with EVOH as the resin film substrate and aluminum vapor deposition on both sides, and a PEN with the resin film substrate as aluminum vapor deposition bonded together on the vapor deposition surfaces (this experiment In the example, a double-sided EVOHPEN aluminum vapor deposition is used), a gas barrier layer that has been subjected to aluminum vapor deposition using EVOH as a resin film substrate, and a film that has aluminum vapor deposited using PEN as a resin film substrate are bonded together on the vapor deposition surfaces. Was used as a resin film substrate, and a film obtained by evaporating aluminum and bonding it to the EVOH side (referred to as EVOHPEN2 aluminum evaporation in this experimental example) was prepared.

The internal pressure of the vacuum heat insulating material is measured in advance,
After that, aluminum foil, aluminum evaporated PET, aluminum evaporated EV
OH, EVOHPEN aluminum evaporation, EVOHPET aluminum evaporation, double-sided EVOHPEN aluminum evaporation, EVOHPE
A heat resistance test was performed by placing N2 aluminum deposition in a constant temperature bath at 100 ° C. Then, the changes over time of these internal pressures were measured, and when the pressure exceeded 30 torr, the life of the vacuum heat insulating material was determined. From the experimental results, the life of various vacuum insulation materials was shown (Table 2).
Shown in

[0034]

[Table 2]

From Table 2, it can be seen that the use of EVOH vapor-deposited as a gas barrier layer makes it possible to realize an electric water heater with low heat-retention power that does not deteriorate the heat insulation performance for a long time. In addition, evaporation is performed on the heat-resistant resin film, and EV
OH and vapor-deposited surfaces, sealing layer and EV
By arranging the gas barrier layer between the OHs, it is possible to realize an electric water heater with a low heat retention power that does not deteriorate the heat insulation performance for a long time.

[0036]

As described above, according to the present invention, by using a copolymer resin film of ethylene and vinyl alcohol as a vapor deposition base material, the vapor deposition layer does not deteriorate for a long time even at a high temperature. It is possible to realize an electric water heater with low heat retention power that does not deteriorate in performance.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric water heater according to the present invention.

FIG. 2 is a cross-sectional view of one embodiment of a vacuum heat insulating material in the electric water heater of the present invention.

FIG. 3 is a sectional view of another embodiment of the vacuum heat insulating material in the electric water heater of the present invention.

FIG. 4 is a plan view of a vacuum heat insulating material in the electric water heater of the present invention.

FIG. 5 is an external view of a vacuum heat insulating material in the electric water heater of the present invention.

[Explanation of symbols]

 2 Water Storage Container 13 Heater 20 Vacuum Insulation Material 22 Core Material 24 Laminate Film 25 Seal Layer 26 Resin Film Base 27 Vapor Deposition Layer 28 Gas Barrier Layer 29 Protective Layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takahito Ishii 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Terms (reference) 3H036 AA09 AB01 AB15 AB23 AB28 AC01 AD01 AE02 4B002 AA18 BA02 CA32 CA34 4B055 AA35 BA22 BA23 CA17 CB04 CB16 CB18 CC46 DA02 DB02 FA20 FB34 FC11 FD10

Claims (7)

[Claims] 1. A water storage container, a heater for heating water in the water storage container, a tapping path for discharging water, and a vacuum heat insulating material, wherein the vacuum heat insulating material is a gas barrier layer, Layer, a laminated film consisting of a seal layer, a heat insulating core material is vacuum-sealed, and the gas barrier layer is formed from a vapor-deposited film obtained by vapor-depositing at least a copolymer resin film base of ethylene and vinyl alcohol. Become an electric water heater. 2. The gas barrier layer according to claim 1, wherein the gas barrier layer is a laminated film formed by laminating one or a plurality of vapor-deposited films laminated so that the vapor-deposited surfaces of vapor-deposited films obtained by vapor-depositing a resin film substrate face each other. Electric water heater. 3. The gas barrier layer comprises a vapor-deposited film obtained by vapor-depositing a copolymer resin film substrate of ethylene and vinyl alcohol and a vapor-deposited film obtained by vapor-depositing a heat-resistant resin film substrate such that the vapor-deposited surfaces face each other. The electric water heater according to claim 1 or 2, further comprising a laminated film formed by laminating a vapor-deposited film obtained by vapor-depositing the copolymer resin film of ethylene and vinyl alcohol on a heat insulating core material side. 4. The electric water heater according to claim 1, wherein a vapor-deposited film obtained by vapor-depositing a heat-resistant resin film substrate is provided between the gas barrier layer and the seal layer. 5. A vapor-deposited film on both surfaces of a copolymer resin film substrate of ethylene and vinyl alcohol.
An electric kettle according to any one of the preceding claims. 6. The heat-resistant resin film substrate is made of at least one of polyethylene terephthalate, polyethylene naphthalate, polyphenyl sulfide, and polyimide.
The electric water heater according to claim 3 or 4, which comprises one. 7. The electric water heater according to claim 1, wherein the deposit obtained by depositing the copolymer resin film substrate contains at least one of aluminum, alumina and silica.