JP7528651B2 - Insulated containers and containers for preserved foods - Google Patents

Description

This embodiment relates to an insulated container and a container containing preserved food.

In recent years, there has been a demand to keep disaster prevention supplies in enclosed spaces such as disaster prevention warehouses in preparation for disasters. Some disaster prevention supplies include preserved food and drinking water. However, if preserved food and drinking water are left in an enclosed space such as a disaster prevention warehouse during hot seasons such as summer, the temperature inside the enclosed space will rise. In this case, there is a risk that the quality of the preserved food and drinking water will deteriorate more quickly.

JP 2019-196223 A

The present disclosure provides an insulated container and a container for preserved food that can prevent the temperature of the contents from rising excessively even when left in an enclosed space during hot periods such as summer.

The insulated container according to this embodiment comprises six planar members arranged in a rectangular parallelepiped shape, each of which includes vacuum insulation material, and a water-filled container that is arranged in the internal space formed by the six planar members and contains water, the volume of the water being 20% or more of the volume of the internal space.

The insulated container according to this embodiment may further include a storage box for storing the six surface members.

In the insulated container according to this embodiment, the six surface members include a first surface member, a second surface member, a third surface member, a fourth surface member, a fifth surface member, and a sixth surface member, and the first surface member and the second surface member face each other, the third surface member and the fourth surface member face each other, the fifth surface member and the sixth surface member face each other, the first surface member, the third surface member, and the fourth surface member are integrated with each other to form a first vacuum insulation member, the second surface member, the fifth surface member, and the sixth surface member are integrated with each other to form a second vacuum insulation member, and the first vacuum insulation member and the second vacuum insulation member may be constructed from separate members.

The container containing preserved food according to this embodiment includes an insulated container according to this embodiment and preserved food contained in the insulated container.

In the container containing preserved food according to this embodiment, the water may be drinking water.

According to this embodiment, even if the insulated container is left in an enclosed space during hot seasons such as summer, excessive temperature rise of the contents can be suppressed.

1 is an exploded perspective view showing a container containing preserved food and a heat-insulating container according to one embodiment. FIG. FIG. 2 is a perspective view showing a container containing preserved food and an insulated container according to one embodiment. 3 is a horizontal cross-sectional view (cross-sectional view taken along line III-III in FIG. 2) showing a container containing preserved food and a heat-insulating container according to one embodiment. 4 is a vertical cross-sectional view (cross-sectional view taken along line IV-IV in FIG. 2) showing a container containing preserved food and a heat-insulating container according to one embodiment. 2 is a vertical cross-sectional view (cross-sectional view taken along line VV in FIG. 2) showing a container containing preserved food and an insulated container according to one embodiment. 4 is a cross-sectional view showing a vacuum insulation material included in a surface member. FIG. 1 is a graph showing a simulation of the change in water temperature when the ratio [%] of the volume of water to the volume of the internal space of the insulated container A is changed. 13 is a graph showing a simulation of the change in water temperature when the ratio [%] of the volume of water to the volume of the internal space of the insulated container B is changed.

An embodiment will be described below with reference to the drawings. Each of the figures shown below is a schematic illustration. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, appropriate modifications can be made without departing from the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values such as dimensions of each member and the names of materials described in this specification are examples of an embodiment, and are not limited to these, and can be selected and used as appropriate. In this specification, terms that specify shapes or geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings.

In the following embodiments, the "X direction" is a direction parallel to one side of the rectangular parallelepiped that constitutes the insulated container, and the "Y direction" is a direction parallel to another side of the rectangular parallelepiped that constitutes the insulated container and perpendicular to the X direction. The "Z direction" is a direction parallel to yet another side of the rectangular parallelepiped that constitutes the insulated container and perpendicular to both the X and Y directions.

The configuration of the container containing preserved food and the insulated container according to this embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is an exploded perspective view showing the container containing preserved food and the insulated container. Fig. 2 is a perspective view showing the container containing preserved food and the insulated container, and Figs. 3 to 5 are cross-sectional views showing the container containing preserved food. Note that the storage box 30 is omitted from Fig. 2.

As shown in Figures 1 to 5, the container 50 containing preserved food according to this embodiment includes an insulated container 10 and preserved food F contained in the insulated container 10. The insulated container 10 has six surface members 11 to 16 and a water-filled container 21 that contains water. The six surface members 11 to 16 are arranged in a rectangular parallelepiped shape and each includes vacuum insulation material. The water-filled container 21 is placed in an internal space S formed by the six surface members 11 to 16. The volume Vw of the water contained in the water-filled container 21 is 20% or more of the volume Vs of the internal space S. The six surface members 11 to 16 are also contained in a storage box 30.

Next, the insulated container 10 will be described. As described above, the insulated container 10 has six surface members 11-16 that include vacuum insulation material, and a water-filled container 21 that contains water. The six surface members 11-16 are formed in a roughly rectangular shape. The surface members 11-16 include a first surface member 11, a second surface member 12, a third surface member 13, a fourth surface member 14, a fifth surface member 15, and a sixth surface member 16. In this specification, the first surface member 11, the second surface member 12, the third surface member 13, the fourth surface member 14, the fifth surface member 15, and the sixth surface member 16 are collectively referred to as surface members 11-16.

The first surface member 11 and the second surface member 12 face each other across the internal space S. The third surface member 13 and the fourth surface member 14 face each other across the internal space S. The fifth surface member 15 and the sixth surface member 16 face each other across the internal space S.

The first surface member 11 is disposed on the top surface side (positive side in the Z direction) of the insulated container 10. The first surface member 11 is a plate-like member and has a rectangular shape in a plan view.

The second surface member 12 is disposed on the bottom side (negative side in the Z direction) of the insulated container 10. The second surface member 12 is positioned parallel to the first surface member 11. The second surface member 12 is a plate-like member having a rectangular shape in a plan view. The water-filled container 21 and the preserved food F are placed on the second surface member 12. The shapes (planar shape and/or thickness) of the first surface member 11 and the second surface member 12 may be the same as each other or may be different from each other.

The third surface member 13 is disposed on the right side (positive side in the X direction) of the insulated container 10. The third surface member 13 is positioned perpendicular to the first surface member 11 and the second surface member 12. The third surface member 13 is a plate-like member and has a rectangular shape in a plan view.

The fourth surface member 14 is disposed on the left side (negative side in the X direction) of the insulated container 10. The fourth surface member 14 is positioned parallel to the third surface member 13. The fourth surface member 14 is a plate-like member and has a rectangular shape in a plan view. The shapes (planar shape and/or thickness) of the third surface member 13 and the fourth surface member 14 may be the same as each other or may be different from each other.

The fifth surface member 15 is disposed on the front side (negative side in the Y direction) of the insulated container 10. The fifth surface member 15 is positioned perpendicular to the first surface member 11 and the second surface member 12, and perpendicular to the third surface member 13 and the fourth surface member 14. The fifth surface member 15 is a plate-like member and has a rectangular shape in a plan view.

The sixth surface member 16 is disposed on the rear side (positive side in the Y direction) of the insulated container 10. The sixth surface member 16 is positioned parallel to the fifth surface member 15. The sixth surface member 16 is a plate-like member and has a rectangular shape in a plan view. The shapes (planar shape and/or thickness) of the fifth surface member 15 and the sixth surface member 16 may be the same as each other or may be different from each other.

The thickness T1 (see FIG. 5) of each of the surface members 11-16 is preferably, for example, 3 mm or more and 30 mm or less, and more preferably 5 mm or more and 15 mm or less. The thickness T1 of each of the surface members 11-16 is the distance perpendicular to the main surface of each of the surface members 11-16, and refers to the thickness at the thickest part within the main surface. The thickness T1 of each of the surface members 11-16 may be the same as each other, or the thickness T1 of each of the surface members 11-16 may be different from each other.

In this embodiment, the first surface member 11, the third surface member 13, and the fourth surface member 14 are integrated with each other to form the first vacuum insulation member 17. The second surface member 12, the fifth surface member 15, and the sixth surface member 16 are integrated with each other to form the second vacuum insulation member 18. The first vacuum insulation member 17 and the second vacuum insulation member 18 are composed of separate members.

When viewed from the front side (negative Y-side), the first vacuum insulation member 17 is in an inverted U-shape (C-shape) that is open to the bottom side (negative Z-side). The third surface member 13 and the fourth surface member 14 are connected to both sides of the first surface member 11 in the X-direction, respectively, to form the first vacuum insulation member 17. A groove portion 26a is formed between the first surface member 11 and the third surface member 13. A groove portion 26b is formed between the first surface member 11 and the fourth surface member 14. The first vacuum insulation member 17 is formed into an inverted U-shape (C-shape) by bending a single plate-shaped member containing vacuum insulation material at the two groove portions 26a and 26b (see the imaginary line in FIG. 1). At this time, the third surface member 13 and the fourth surface member 14 are each bent so as to be perpendicular to the first surface member 11.

The second vacuum insulation member 18 is U-shaped (C-shaped) when viewed from the side (positive side in the X direction) and opens to the top side (positive side in the Z direction). The fifth surface member 15 and the sixth surface member 16 are connected to both sides of the second surface member 12 in the Y direction, respectively, to form the second vacuum insulation member 18. A groove portion 27a is formed between the second surface member 12 and the fifth surface member 15. A groove portion 27b is formed between the second surface member 12 and the sixth surface member 16. The second vacuum insulation member 18 is formed into a U-shape (C-shape) by bending a single plate-shaped member containing vacuum insulation material at the two groove portions 27a and 27b (see the imaginary line in FIG. 1). At this time, the fifth surface member 15 and the sixth surface member 16 are each bent so as to be perpendicular to the second surface member 12.

By combining the first vacuum insulation member 17 and the second vacuum insulation member 18, which are constructed separately in this manner, the six surface members 11 to 16 are formed in a substantially rectangular parallelepiped shape. At this time, the third surface member 13 and the fourth surface member 14 of the first vacuum insulation member 17 and the fifth surface member 15 and the sixth surface member 16 of the second vacuum insulation member 18 are arranged so as to be perpendicular to each other. In addition, the first vacuum insulation member 17 and the second vacuum insulation member 18 are detachable from each other. Therefore, for example, by removing the first vacuum insulation member 17 from the second vacuum insulation member 18, the preserved food F or the water-filled container 21 can be taken out. After that, the first vacuum insulation member 17 is attached so as to cover the second vacuum insulation member 18, and the six surface members 11 to 16 become rectangular parallelepiped, and an internal space S with thermal insulation properties is formed.

The six surface members 11-16 do not necessarily have to be made up of two U-shaped (C-shaped) vacuum insulation members (first vacuum insulation member 17 and second vacuum insulation member 18). For example, the six surface members 11-16 may be made up of a single member as a whole. Also, the six surface members 11-16 may each be made up separately and independently, and these six surface members 11-16 may be combined to form an approximately rectangular parallelepiped shape.

Next, the vacuum insulation material included in the surface members 11 to 16 will be described. As shown in FIG. 6, the vacuum insulation material 40 included in the surface members 11 to 16 may have a core material 41 and an exterior material 42. The core material 41 may be, for example, a porous material such as a powder such as silica, a foam such as a urethane polymer, or a fibrous material such as glass wool. The exterior material 42 is a member that covers the outer periphery of the core material 41, and may be a flexible sheet in which a heat-sealed layer and a gas barrier layer are laminated in this order from the core material 41. The gas barrier layer may be a metal foil, a vapor deposition sheet in which a vapor deposition layer is formed on one side of a resin sheet, or the like. The metal foil may be, for example, aluminum. The vapor deposition layer may be, for example, aluminum, aluminum oxide, or silicon oxide.

Next, the dimensions of the insulated container 10 will be described with reference to Figures 3 and 4. The dimensions of the insulated container 10 need only be large enough to accommodate the preserved food F and the water-filled container 21 inside, and can be set appropriately depending on the application (e.g., the type and required amount of the preserved food F, the location where the container 50 containing the preserved food is to be stored, etc.).

As an example, the length L1 (external dimension) along the X direction of the rectangular parallelepiped formed by the six surface members 11 to 16 may be 50 mm or more and 1000 mm or less, and preferably 200 mm or more and 500 mm or less. The length L2 (external dimension) along the Y direction of the rectangular parallelepiped may be 50 mm or more and 1000 mm or less, and preferably 200 mm or more and 500 mm or less. Furthermore, the length L3 (external dimension) along the Z direction of the rectangular parallelepiped may be 30 mm or more and 500 mm or less, and preferably 50 mm or more and 300 mm or less.

The length L4 of the internal space S surrounded by the six surface members 11 to 16 along the X direction may be 30 mm or more and 800 mm or less, and preferably 160 mm or more and 400 mm or less. The length L5 of the internal space S along the Y direction may be 30 mm or more and 800 mm or less, and preferably 200 mm or more and 500 mm or less. The length L6 of the internal space S along the Z direction may be 20 mm or more and 400 mm or less, and preferably 40 mm or more and 250 mm or less.

Next, the storage box 30 will be described. As shown in FIG. 1, FIG. 3 to FIG. 5, the storage box 30 has a box body 31 and a lid member 34 that is attached to the box body 31 so as to be freely opened and closed. The box body 31 has a box bottom surface 32 and four box side surfaces 33 located around the box bottom surface 32. The second surface member 12 is placed on the box bottom surface 32. The four box side surfaces 33 are respectively arranged around the third surface member 13, the fourth surface member 14, the fifth surface member 15 and the sixth surface member 16. The lid member 34 also has a lid top surface 35 and four lid side surfaces 36 located around the lid top surface 35. The lid top surface 35 is arranged on the first surface member 11. The four lid side surfaces 36 are arranged around the four box side surfaces 33.

The six surface members 11 to 16 are stored in the storage box 30. The storage box 30 is provided to stably hold the six surface members 11 to 16 in a rectangular parallelepiped state. Therefore, if the six surface members 11 to 16 themselves are stable in a rectangular parallelepiped shape, the storage box 30 does not necessarily have to be provided. The storage box 30 does not have to be composed of two members (the box body 31 and the lid member 34), and may be composed of, for example, one member including a bottom surface, four side surfaces, and a top surface. The storage box 30 is also composed of the box body 31, and may not have a lid member 34. In this case, the storage box 30 may be open on the top surface (first surface member 11) side.

The dimensions of the storage box 30 need only be sufficient to stably hold the six surface members 11 to 16. It is preferable that the length of each side of the storage box 30 is slightly longer than each side of the rectangular parallelepiped formed by the six surface members 11 to 16. For example, it is preferable that the length of each side of the storage box 30 is approximately 5 mm to 20 mm longer than the length of the rectangular parallelepiped formed by the six surface members 11 to 16 (the above-mentioned lengths L1, L2, L3). In addition, the storage box 30 does not necessarily have to have high thermal insulation properties. Materials for the storage box 30 may include paper such as coated cardboard and corrugated cardboard, wood, synthetic resin, etc.

The preserved food F contained in the insulated container 10 may be food that has been processed or treated to inhibit spoilage so that it can be stored for a relatively long period of time (several months to several years). The preserved food F is placed in the internal space S of the six surface members 11-16 while being contained in a container such as a bag. In this case, multiple preserved foods F may be contained in the internal space S, and multiple preserved foods F may be arranged side by side in each of the X direction, Y direction, and Z direction. The preserved food F is also placed between the two water containers 21. However, this is not limited to this, and the number of preserved foods F may be any number greater than one. The preserved foods F may also be placed in any position within the internal space S.

The water container 21 is a container that contains water. The material of the container may be, for example, a resin such as a thermoplastic resin. As such a thermoplastic resin, for example, PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate) or ionomer resin is preferably used. The water contained in the water container 21 is preferably drinking water that can be consumed by humans. Drinking water is drinkable water that contains components that are beneficial to the human body, and is preferably usable for drinking by humans, for cooking food, or for cooking rice. Specifically, the drinking water may be tap water, mineral water, etc. Alternatively, the water contained in the water container 21 may be a drinkable beverage that is mainly composed of water, such as juice.

In this case, two water-filled containers 21 are placed in the internal space S, but the number of water-filled containers 21 may be any number greater than or equal to one. The water-filled containers 21 may be placed at any position in the internal space S. If the water-filled containers 21 are placed near each side of the rectangular parallelepiped that constitutes the internal space S, the water in the water-filled containers 21 can efficiently absorb the heat that enters through the gaps between the surface members 11 to 16, further improving the insulation of the internal space S.

In this embodiment, the volume Vw of water contained in the water container 21 is 20% or more of the volume Vs of the internal space S (Vw/Vs≧0.2). This volume Vw of water is the total volume of water in all water containers 21 contained in the internal space S, and refers to the volume measured at room temperature and normal pressure (25°C and 1 atm). The volume Vs of the internal space S refers to the volume of the internal space S formed by the six surface members 11-16 when nothing is placed inside. For example, when the internal space S is a rectangular parallelepiped as in this embodiment, the volume Vs of the internal space S can be calculated by L4×L5×L6.

By making the volume Vw of water contained in the water container 21 20% or more of the volume Vs of the internal space S, it is possible to prevent the temperature inside the internal space S from reaching a temperature that affects the quality of the food. Specifically, even if the container 50 containing preserved food is left in an enclosed space such as a warehouse during hot seasons such as summer, the temperature of the internal space S can be prevented from exceeding 40°C. The volume Vw of water may be 25% or more, 30% or more, 35% or more, or 40% or more of the volume Vs of the internal space S. The volume Vw of water may be less than 100% of the volume Vs of the internal space S, and may be 60% or less, 50% or less. By making the ratio of the volume Vw of water to the volume Vs of the internal space S within the above range, it is possible to ensure sufficient space for containing the preserved food F. For example, the volume Vw of water may be 20% or more and 40% or less, 20% or more and 60% or less, or 30% or more and 50% or less of the volume Vs of the internal space S.

Next, we will explain the operation of this embodiment with such a configuration.

First, the container 50 containing preserved food is assembled. In this case, the box body 31 of the storage box 30 is first prepared, and the second vacuum insulation member 18 is accommodated in this box body 31. At this time, the second vacuum insulation member 18 is arranged so that the second surface member 12 is on the box bottom surface 32 side. Next, the preserved food F and the water-filled container 21 are arranged side by side on the second surface member 12. Next, the first vacuum insulation member 17 is accommodated in the box body 31. At this time, the first vacuum insulation member 17 is arranged so that the first surface member 11 is on the top surface side. As a result, the six surface members 11 to 16 are formed into a rectangular parallelepiped shape, and an insulated internal space S is formed inside. In this way, the six surface members 11 to 16 and the water-filled container 21 arranged in the internal space S constitute the insulated container 10. After that, the lid member 34 is attached to the box body 31, and the assembly of the container 50 containing preserved food is completed.

The container 50 containing the preserved food obtained in this manner may be stored in an enclosed space such as a disaster prevention warehouse and left there for a long period of time (several months to several years). During this time, in hot seasons such as summer, the temperature of the enclosed space is expected to rise and reach a temperature higher than the outside air temperature. Specifically, the temperature of the enclosed space may rise to 45°C or higher, 50°C or higher, or even up to about 55°C. If the container 50 containing the preserved food is left in an enclosed space under such circumstances, it is thought that the quality of the preserved food F in the container 50 containing the preserved food and the water in the water container 21 will deteriorate.

In contrast, in this embodiment, the insulated container 10 has six surface members 11-16 each including vacuum insulation material, and the preserved food F and water-filled container 21 are housed in the internal space S formed by these six surface members 11-16. Vacuum insulation material is thin but has high insulating properties. The entire internal space S formed by the six surface members 11-16 is surrounded by vacuum insulation material, which increases the insulating properties of the internal space S. This makes it possible to suppress the temperature rise of the preserved food F and water placed in the internal space S.

Furthermore, in this embodiment, a water-filled container 21 is placed in the internal space S, and the volume Vw of the water contained in this water-filled container 21 is 20% or more of the volume Vs of the internal space S. By having water with a large specific heat capacity occupy a certain proportion of the volume of the internal space S, the temperature rise in the internal space S can be further suppressed. This makes it possible to suppress the temperature rise of the preserved food F and water placed in the internal space S.

Specifically, even if the container 50 containing the preserved food is left in an enclosed space such as a warehouse during hot seasons such as summer, the temperature of the internal space S can be prevented from exceeding 40°C. It is generally believed that when the temperature of the preserved food F and water exceeds 40°C, the quality deteriorates quickly. The temperature of the enclosed space during hot seasons such as summer peaks during the day and drops as the sun sets. As the temperature in the enclosed space changes, the temperature of the preserved food F and water also changes, but in order to maintain quality, it is necessary to maintain them at a guideline of 40°C or less. In this embodiment, the entire internal space S formed by the six surface members 11 to 16 is surrounded by vacuum insulation material, and the volume Vw of the water contained in the water-filled container 21 is 20% or more of the volume Vs of the internal space S. As a result, the high insulation properties of the vacuum insulation material and the heat capacity of the water make it possible to maintain the temperature of the internal space S at 40°C or less.

In addition, according to this embodiment, the insulated container 10 further includes a storage box 30 that stores the six surface members 11 to 16. This allows the rectangular parallelepiped shape formed by the six surface members 11 to 16 to be stably maintained. This prevents the shape of the six surface members 11 to 16 from collapsing, and prevents gaps from occurring between the surface members 11 to 16, which would otherwise reduce the insulating properties of the internal space S.

In addition, according to this embodiment, the first vacuum insulation member 17 and the second vacuum insulation member 18 are constructed from separate members. This makes it easy to remove and store the preserved food F and the water-filled container 21 by removing the second vacuum insulation member 18 from the first vacuum insulation member 17. Also, by attaching the second vacuum insulation member 18 to the first vacuum insulation member 17, the rectangular parallelepiped internal space S can be easily formed by the six surface members 11 to 16.

Furthermore, according to this embodiment, the water contained in the water container 21 is drinking water. In this case, the temperature rise in the internal space S can be suppressed by using the stored drinking water, so that the internal space S can be used efficiently.

According to this embodiment, the above-mentioned configuration makes it possible to suppress the temperature rise in the internal space S of the insulated container 10 without placing an ice pack in the internal space S. In this case, the container 50 containing the preserved food can be easily constructed, and an increase in the cost of the container 50 containing the preserved food can be suppressed. Furthermore, by not placing an ice pack, the internal space S can be effectively utilized. However, this is not limited to the above, and an ice pack may be placed in the internal space S of the insulated container 10.

(simulation)
Next, the relationship between the ratio of the volume of water to the volume of the internal space of the insulated container and the temperature rise in the internal space of the insulated container will be described using a simulation.

When the temperature outside the insulated container is high and the temperature of the internal space of the insulated container is low, the amount of heat Q [J] flowing from the outside to the inside of the insulated container during a given time t [hr] can be expressed by the following equation (1).
Q=( _qA + _qB )×t...Formula (1)
Here, _qA is the amount of heat per unit time [J/hr] flowing in through the surface members that make up the insulated container, and _qB is the amount of heat per unit time [J/hr] flowing in through gaps such as between the surface members of the insulated container.

The amount of heat per unit time q _A [J/hr] flowing through the planar members constituting the insulated container can be expressed by the following formula (2).
q _A = U x L x ΔT x 3600...Formula (2)
Here, U is the average thermal conductivity [W/( ^m2 × K)] of each surface component that makes up the insulated container, L is the surface area [ ^m2 ] of the inner side of the insulated container, and ΔT is the temperature difference [K] between the inside and outside of the insulated container.

The amount of heat per unit time q _B [J/hr] flowing through gaps between the planar members of the insulated container can be expressed by the following formula (3).
q _B =D×a×C×ΔT...Formula (3)
Here, D is the air gap volume [ ^m3 /hr], which can be expressed as the product of the ventilation rate [times/hr] and the volume of the internal space of the insulated container [ ^m3 ]. Also, a is the environmental coefficient, C is the heat capacity of the air [J/( ^m3 x K)], and ΔT is the temperature difference [K] between the inside and outside of the insulated container. In this simulation, the air gap volume was 0.5 ^m3 /hr, the environmental coefficient was 5.34, the specific heat capacity of the air was 1.0 J/(g x K), and the density of the air was 1.3 x ¹⁰³ g/ ^m3 .

The environmental coefficient a is a multiplying factor that reflects the influence of environmental factors such as the temperature difference between the outside and inside of the insulated container and the wind speed outside the insulated container. This is because the movement of air flowing in through gaps between the surface members of the insulated container is influenced not only by factors of the insulated container itself, such as the size and shape of the gaps between the surface members, but also by environmental factors.

The insulated containers were two types of rectangular parallelepipeds (insulated container A and insulated container B) whose all sides were surrounded by surface members including vacuum insulation material. The insulated container A had dimensions of 230 mm x 180 mm x 90 mm in width x depth x height, and the insulated container B had dimensions of 230 mm x 300 mm x 60 mm in width x depth x height. The surface members included vacuum insulation material (thermal conductivity 0.003 W/(m x K), thickness 10 mm). The thermal conductivity U of this surface member was 0.3 (W/( ^m2 x K)).

The temperature outside the insulated container was set to rise linearly from 25°C to 55°C over 7 hours, then remain at 55°C for 1 hour, and then fall from 55°C to 25°C over 7 hours. This setting assumes that the insulated container will be left in an enclosed space such as a warehouse during the Japanese summer (maximum temperature 30°C to 35°C).

We also assumed that a certain volume of water was placed inside the insulated container. The percentage of the volume of water in the volume of the internal space of the insulated container was changed as follows for insulated container A (230 mm x 180 mm x 90 mm) and insulated container B (230 mm x 300 mm x 60 mm).

For insulated container A, the ratio of the volume of water to the volume of the internal space of the insulated container was set to 6.7%, 15.0%, 17.5%, 18.0%, 20.0%, 26.8%, and 40.3%, respectively. For insulated container B, the ratio of the volume of water to the volume of the internal space of the insulated container was set to 12.1%, 15.0%, 17.5%, 20.0%, 24.2%, and 36.2%, respectively.

From the above, the time [h] until the temperature (water temperature) of the water placed inside the insulated container reaches 40° C. was calculated for each of the insulated containers A and B. Specifically, the time until the amount of heat Q [J] flowing from the outside into the internal space of the insulated container reaches the amount of heat _Qw [J] required for the water to rise from its initial temperature (25° C.) to 40° C. was calculated. The results are shown in Table 1 below.

Figure 7 shows the results of a simulation of the change in water temperature when the percentage [%] of the water volume in the volume of the internal space of the insulated container A was changed. As is clear from Figure 7 and Table 1 above, as the percentage [%] of the water volume in the volume of the internal space of the insulated container A increased, the time it took for the temperature of the water placed inside the insulated container (water temperature) to reach 40°C became longer. In particular, when the percentage [%] of the water volume in the volume of the internal space of the insulated container A was set to 20% or more, the water temperature never reached 40°C.

Figure 8 shows the results of a simulation of the change in water temperature when the percentage [%] of the volume of water in the volume of the internal space of insulated container B is changed. As is clear from Figure 8 and Table 1 above, as the percentage [%] of the volume of water in the volume of the internal space of insulated container B increases, the time it takes for the temperature of the water placed inside the insulated container (water temperature) to reach 40°C becomes longer. In particular, when the percentage [%] of the volume of water in the volume of the internal space of insulated container B is set to 20% or more, the water temperature never reaches 40°C.

(Example)
Next, a specific example of this embodiment will be described.

A container containing preserved food was produced, comprising an insulated container and preserved food contained in the insulated container, and an experiment similar to the simulation was carried out under the following conditions.
・Insulated container dimensions: 230mm x 300mm x 60mm
・Insulated container volume: 4.1× ^{10-3 m3}
・Water volume: 1000mL (2 500mL plastic bottles)
Water occupancy rate (proportion of water volume to the volume of the internal space of the insulated container): 24.2%
Vacuum insulation thickness: 10 mm

Two plastic bottles (containers containing water) were placed on either side of an insulated container, and preserved food (a pouch containing cooked rice) was placed between the two plastic bottles.

The container containing the preserved food was placed in a programmable oven to allow the temperature to change. Specifically, the temperature inside the oven was raised linearly from 25°C to 55°C over a period of 7 hours, then maintained at 55°C for 1 hour, and then lowered from 55°C to 25°C over a period of 7 hours. A thermocouple was also attached to the surface of the PET bottle (water container) to measure the temperature of the water on the surface of the PET bottle. The measurements were taken at 1 second intervals.

As a result, the water temperature never exceeded 40°C. The highest temperature the water reached was 35.8°C.

The multiple components disclosed in the above embodiments and modifications may be combined as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiments and modifications.

10 Heat insulation container 11 First surface member 12 Second surface member 13 Third surface member 14 Fourth surface member 15 Fifth surface member 16 Sixth surface member 17 First vacuum insulation member 18 Second vacuum insulation member 21 Water container 30 Storage box 31 Box body 32 Box bottom 33 Box side 34 Lid member 35 Lid top 36 Lid side 50 Container containing preserved food

Claims (4)

An insulating container having six planar members arranged in a rectangular parallelepiped shape, each planar member including a vacuum insulating material;
A preserved food contained in the insulated container;
a water container that contains drinking water and is disposed in an internal space formed by the six surface members of the insulated container ;
A container containing preserved food , wherein the volume of the drinking water is between 20% and 60% of the volume of the internal space. The container of claim 1 further comprising a container for housing the six face members. the six surface members include a first surface member, a second surface member, a third surface member, a fourth surface member, a fifth surface member, and a sixth surface member,
the first surface member and the second surface member face each other, the third surface member and the fourth surface member face each other, the fifth surface member and the sixth surface member face each other,
the first surface member, the third surface member, and the fourth surface member are integrated with each other to form a first vacuum insulation member,
the second surface member, the fifth surface member, and the sixth surface member are integrated with each other to form a second vacuum insulation member,
The container containing preserved food according to claim 1 or 2, wherein the first vacuum insulation member and the second vacuum insulation member are formed of separate members. The container containing preserved food according to claim 1 , wherein no ice pack is placed in the internal space of the insulated container.

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