JP7804409B2 - Latent heat storage materials, cooling devices, logistics packaging containers, and food cooling devices - Google Patents

Description

This disclosure relates to latent heat storage materials, cooling devices, logistics packaging containers, and food cooling devices.

When frozen foods are transported, they are often packed into logistics containers, and the logistics containers containing the frozen foods are then transported.

To maintain the quality of frozen foods during transportation, they must be kept at least below freezing, and depending on the type of frozen food, it is desirable to maintain temperatures below -10°C, -15°C, or -18°C. However, until now, dry ice has been used to transport frozen foods regardless of the required temperature.

However, in recent years, there has been a shortage of liquefied carbon dioxide, the raw material for dry ice, with shortages particularly severe in the summer. Demand for liquefied carbon dioxide is diverse, and it is only natural that priority should be given to supplying it to medical facilities where lives are at stake. For this reason, the logistics sector is increasingly using latent heat storage materials as an alternative to dry ice.

The refrigeration heat storage material described in Patent Document 1 contains water and at least one ammonium salt selected from the group consisting of ammonium chloride, ammonium bromide, ammonium sulfate, and ammonium nitrate. A refrigeration heat storage material with this composition has a melting point in the range of -15°C to -22°C, a large heat of fusion, and excellent phase change stability.

Japanese Patent Application Publication No. 63-312387

Latin heat storage materials must be solidified before use. However, latent heat storage materials made from inorganic salts and water are prone to a phenomenon known as supercooling, where they do not begin to solidify even at temperatures below their melting point. For example, latent heat storage materials with a melting point of around -25°C, which have been primarily used as alternatives to dry ice, require a freezer set to a temperature of -35°C or below to solidify.

In general, the lower the set temperature of a freezer, the more electricity it consumes. Since large amounts of latent heat storage material are required in logistics, the energy consumption required for freezing is enormous. However, as mentioned above, there are different levels of temperature required by frozen foods, and not all foods require latent heat storage material with a melting point around -25°C. In other words, if a latent heat storage material with a higher melting point is used for frozen foods that require a higher cooling temperature than around -25°C, the required set temperature for the freezer can be raised, thereby reducing power consumption.

Among these, latent heat storage materials used in the transportation of frozen foods that require refrigeration at -18°C or below must have a melting point of -18°C or below. Therefore, even if the temperature of a freezer is raised to reduce power consumption, the limit is -20°C. Ideally, a latent heat storage material that solidifies in a -20°C freezer would be able to maintain refrigeration at -18°C or below. Furthermore, frozen foods are often stored in refrigerated warehouses controlled to a temperature range of -20°C to -25°C. If a latent heat storage material that solidifies at -20°C or above were available, it would be possible to coexist with latent heat storage materials used for refrigerated transportation at -18°C or below and solidify them in the refrigerated warehouse. In other words, such latent heat storage materials are sufficient as long as they solidify at -20°C or above and have a melting point of -18°C or below.

This disclosure has been made to solve the above-mentioned problems. The purpose of this disclosure is to provide a latent heat storage material that can be solidified at temperatures above -20°C and can keep items to be refrigerated, such as frozen foods, at temperatures below -18°C.

As a result of extensive research to solve the above-mentioned problems, the inventors discovered that by blending ammonium chloride, ammonium bromide, and water at specific concentrations, a latent heat storage material can be obtained that solidifies at -20°C and melts and absorbs heat at temperatures below -18°C, and they applied this.

The latent heat storage material of the first embodiment of the present disclosure contains 3.5 to 22.5 parts by weight of ammonium chloride, 6.5 to 25.5 parts by weight of ammonium bromide, and water, with the total amount of ammonium chloride, ammonium bromide, and water being 100 parts by weight, and has a melting onset temperature in the range of -18°C to -20°C.

A second embodiment of the ice pack of the present disclosure comprises the latent heat storage material of the first embodiment of the present disclosure and a ice pack main body that contains the latent heat storage material in a liquid-tight manner.

The logistics packaging container and food cooling device of the third embodiment of the present disclosure include the cooling device of the second embodiment of the present disclosure.

A cooling device of the fourth embodiment of the present disclosure comprises the latent heat storage material of the first embodiment of the present disclosure and a cooling device main body having multiple storage sections and multiple joint sections.

The logistics packaging container and food cooling device of the fifth aspect of the present disclosure include the cooling device of the fourth aspect of the present disclosure.

A sixth embodiment of the ice pack of the present disclosure comprises the latent heat storage material of the first embodiment of the present disclosure and a ice pack main body having multiple storage sections and multiple joint sections.

The logistics packaging container and food cooling device of the seventh aspect of the present disclosure include the cooling device of the sixth aspect of the present disclosure.

This disclosure provides a latent heat storage material that can keep items such as frozen foods cold at temperatures below -18°C for long periods of time and has a melting point below -18°C and can solidify at temperatures above -20°C.

1 is a table showing the composition of latent heat storage materials according to examples and comparative examples. FIG. 2 is a diagram illustrating a method for measuring the melting start temperature and latent heat quantity of a latent heat storage material according to an example. FIG. 2 is a diagram showing the solidification characteristics of the latent heat storage materials of Examples 1, 2, and 3. FIG. 2 is a diagram showing the melting characteristics of the latent heat storage material of Example 1. FIG. 10 is a longitudinal cross-sectional view schematically illustrating a human body cooling device according to a second embodiment. FIG. 10 is a cross-sectional view schematically illustrating a human body cooling device according to a second embodiment. FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. FIG. 10 is a cross-sectional view schematically illustrating a logistics packaging container according to a third embodiment. FIG. 10 is a perspective view schematically illustrating a human body cooling device according to a fourth embodiment. FIG. 10 is a cross-sectional view schematically illustrating a human body cooling device according to a fourth embodiment. FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the fourth embodiment. FIG. 10 is a cross-sectional view schematically illustrating a logistics packaging container according to a fifth embodiment. FIG. 13 is a cross-sectional view schematically illustrating a logistics packaging container according to a modified example of the fifth embodiment. FIG. 13 is a plan view schematically illustrating a human body cooling device according to a sixth embodiment. FIG. 13 is a cross-sectional view schematically illustrating a human body cooling device according to a sixth embodiment. FIG. 13 is a perspective view schematically illustrating a human body cooling device according to a modified example of the sixth embodiment. FIG. 13 is a cross-sectional view schematically illustrating a human body cooling device according to a modified example of the sixth embodiment. FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling device of the sixth embodiment is manufactured. FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling device of the sixth embodiment is manufactured. FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling device of the sixth embodiment is manufactured. FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling device of the sixth embodiment is manufactured. FIG. 13 is a cross-sectional view schematically illustrating a logistics packaging container according to a seventh embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the drawings, identical or equivalent elements are designated by the same reference numerals, and duplicate descriptions will be omitted.

1 First embodiment 1.1 Composition of latent heat storage material The latent heat storage material of the first embodiment keeps the object cold at a temperature near its melting point by being brought into proximity with or in contact with the object in a solidified state. The latent heat storage material continues to keep the object cold at a temperature near its melting point until it completely melts.

The latent heat storage material of the first embodiment contains 3.5 to 22.5 parts by weight of ammonium chloride, 6.5 to 25.5 parts by weight of ammonium bromide, and water. The total amount of ammonium chloride, ammonium bromide, and water is 100 parts by weight, and the material has a melting start temperature in the range of -18°C to -20°C.

The latent heat storage material of the first embodiment has a composition within the above-mentioned range, and therefore has a composition close to a eutectic composition. Therefore, in its liquid state, the latent heat storage material consists of a mixed aqueous solution of ammonium chloride and ammonium bromide, but in its solid state, it consists mainly of a eutectic of ammonium chloride, ammonium bromide, and ice. Therefore, when the latent heat storage material is solidified, a eutectic of mainly ammonium chloride, ammonium bromide, and ice is formed. When the latent heat storage material has a composition within the above-mentioned desirable range, almost no solidification components other than the eutectic are formed.

The eutectic of ammonium chloride and ice has a eutectic point at approximately -15°C. The eutectic of ammonium bromide and ice has a eutectic point at approximately -17°C. On the other hand, it was found that the eutectic of ammonium chloride, ammonium bromide, and ice has a eutectic point at approximately -19°C, lower than either of the above eutectics. Furthermore, ammonium chloride and ammonium bromide, which are ionic substances, dissociate into cations and anions when dissolved in water. When multiple ionic substances with different cations and anions are contained, ionic species rearrangement can occur, resulting in the formation of ionic substances different from the contained ionic substances and inhibiting the formation of the eutectic. However, because ammonium chloride and ammonium bromide both have ammonium ions as cations, such ionic species rearrangement and the formation of different ionic substances do not occur. For these reasons, the formation of only a eutectic of ammonium chloride, ammonium bromide, and ice results in a single eutectic point at approximately -19°C. For this reason, the latent heat storage material of the first embodiment has a composition close to a eutectic composition, and therefore has a melting start temperature of approximately -19°C. More specifically, it has a melting start temperature in the range of -18°C to -20°C. As a result, the latent heat storage material begins to melt and absorb heat at temperatures below -18°C, allowing the item to be kept refrigerated at temperatures below -18°C.

The latent heat storage material of the first embodiment preferably contains a water-insoluble supercooling inhibitor such as calcium carbonate, aluminum oxide, or activated carbon. The water-insoluble supercooling inhibitor is dispersed in water. By including a water-insoluble supercooling inhibitor, the phenomenon of supercooling of the latent heat storage material and delaying the start of solidification can be suppressed when the latent heat storage material is solidified at -20°C. Furthermore, the cooling time required to start cooling the latent heat storage material and achieve a state where the object to be cooled can be kept at a temperature of -18°C or below can be shortened, as described above. Furthermore, because solidification can be achieved at -20°C, which is close to -18°C, it is unnecessary to lower the set temperature of equipment such as freezers that solidify the latent heat storage material more than necessary, thereby reducing power consumption. On the other hand, water-soluble supercooling inhibitors such as sodium sulfate and disodium hydrogen phosphate can cause freezing point depression of the latent heat storage material and inhibit solidification at -20°C, and are therefore considered to be less effective than the water-insoluble supercooling inhibitors.

More preferably, the non-water-soluble supercooling inhibitor contains calcium carbonate. The inclusion of calcium carbonate effectively prevents delays in the onset of solidification due to supercooling.

The concentration of the water-insoluble supercooling inhibitor is preferably 0.1 to 10 parts by weight per 100 parts by weight of the total of ammonium chloride, ammonium bromide, and water. At less than 0.1 parts by weight, the effect of inhibiting supercooling is not observed, while as the concentration of the water-insoluble supercooling inhibitor increases, the amount of latent heat per weight of the latent heat storage material becomes relatively smaller, so 10 parts by weight is the limit.

The latent heat storage material of the first embodiment may contain components other than those described above. The components other than those described above may include, for example, at least one selected from the group consisting of a thickener, an antibacterial agent, and a pigment.

<Examples and Comparative Examples of the First Embodiment>
The latent heat storage materials according to the examples and comparative examples were prepared by mixing ammonium chloride, ammonium bromide, water, and a water-insoluble supercooling inhibitor in the weight ratios shown in the table of Fig. 1. The total amount of ammonium chloride, ammonium bromide, and water was adjusted to 100 parts by weight.

Figure 1 also shows the results of the differential scanning calorimetry and coagulation property evaluation described below, including the latent heat, melting onset temperature, and coagulation performance at -20°C.

Figure 2 is a diagram explaining the method for measuring the melting initiation temperature and latent heat quantity of the latent heat storage material of the first embodiment.

When measuring the melting initiation temperature and latent heat quantity of the latent heat storage material of the first embodiment, as shown in Figure 2, a DSC curve 10 is obtained by differential scanning calorimetry (DSC) for the latent heat storage material. The horizontal axis is temperature (T), and the vertical axis is melting enthalpy per unit temperature (dH/dT). The melting initiation temperature is determined as the temperature at the intersection 16 between a straight line 13 obtained by linearly extrapolating the low-temperature side 12 of a melting peak 11 included in the DSC curve 10 and a straight line 15 obtained by linearly extrapolating a low-temperature baseline 14 included in the DSC curve 10. The latent heat quantity is determined as the area of a latent heat region 17 surrounded by the melting peak 11 and the straight line 15 divided by the weight of the latent heat storage material.

As can be seen from Figure 1, the melting start temperatures of the latent heat storage materials of Examples 1 to 15 are all in the range of -18°C to -20°C. In other words, the latent heat storage material of the first embodiment has a melting start temperature in the range of -18°C to -20°C. On the other hand, the melting start temperatures of the latent heat storage materials of Comparative Examples 1 to 6 are all outside the range of -18°C to -20°C.

The solidification characteristics of the latent heat storage materials of the examples and comparative examples were evaluated. A thermocouple was inserted into 40 g of each latent heat storage material of the examples and comparative examples, and the temperature of each latent heat storage material was measured when it solidified. Specifically, each latent heat storage material, maintained at 25°C, was cooled to -20°C in a thermostatic chamber, and the thermocouple was used to measure the temperature change over time of each latent heat storage material. Regarding the solidification characteristics at -20°C shown in Figure 1, a ◎ indicates that the latent heat storage material began to solidify before reaching the ambient temperature of -20°C, a ◯ indicates that it began to solidify after reaching the ambient temperature, and an × indicates that it did not solidify.

The results of the solidification characteristic evaluation of the latent heat storage materials of Examples 1, 2, and 3 are shown in Figure 3.

As can be seen from Figure 3, the latent heat storage material of Example 1 reached the ambient temperature of the thermostatic bath after 5.5 hours, and then after 6.5 hours, a sudden temperature rise occurred due to the start of solidification, and solidification progressed. In other words, the latent heat storage material of the first embodiment can be solidified at -20°C.

On the other hand, the latent heat storage material of Example 2 began to solidify after 3 hours, before reaching the ambient temperature of the thermostatic bath. In other words, by including calcium carbonate, a water-insoluble supercooling inhibitor, at a concentration of 0.1 to 10 parts by weight, supercooling is suppressed, and solidification is possible before the temperature reaches -20°C. This makes it possible to solidify the latent heat storage material in a short time.

The latent heat storage material containing aluminum oxide in Example 3 began to solidify 4.5 hours later than the latent heat storage material containing calcium carbonate in Example 2, before it reached the ambient temperature of the thermostatic bath. In other words, while it is possible to solidify by reaching -20°C by adding a water-insoluble supercooling inhibitor, it is more preferable to add calcium carbonate in order to shorten the solidification time.

In this way, in Examples 1 to 3, the set temperature required for the freezer that solidifies the latent heat storage material can be increased compared to conventional latent heat storage materials, thereby reducing power consumption.

The melting characteristics of the latent heat storage material of Example 1 were evaluated. A thermocouple was inserted into 100 g of the latent heat storage material of Example 1, and the temperature of each latent heat storage material was measured when it melted. Specifically, the latent heat storage material of Example 1 was solidified at -20°C in a constant temperature bath, and then the temperature was raised to -10°C, and the change in temperature of the latent heat storage material over time was measured using the thermocouple.

The results of the melting characteristic evaluation of the latent heat storage material of Example 1 are shown in Figure 4.

Figure 4 shows that the latent heat storage material of Example 1 maintained a temperature of -18°C or below until it completely melted after 4.5 hours and its temperature suddenly rose. In other words, by using the latent heat storage material of the first embodiment to keep an object cold, it is possible to maintain the object at a temperature of -18°C or below.

2 Second embodiment 2.1 Cooling device Fig. 5 is a longitudinal sectional view that schematically illustrates a cooling device 2 of a second embodiment. Fig. 6 is a transverse sectional view that schematically illustrates a cooling device 2 of the second embodiment.

The cooling device 2 keeps the object to be cooled. The object to be cooled is, for example, frozen food that is kept at a temperature of -18°C or below. The cooling device 2 is a so-called blown container type cooling device.

As shown in Figures 5 and 6, the cooling device 2 comprises a latent heat storage material 201 and a cooling device main body 202.

The latent heat storage material 201 is the latent heat storage material of the first embodiment.

The ice pack body 202 contains the latent heat storage material 201 in a liquid-tight manner. The latent heat storage material 201 is contained in an internal space 201c formed in the ice pack body 202.

As shown in Figures 5 and 6, the ice pack body 202 includes a storage member 211, an inlet 212, and a sealing member 213.

The housing member 211 has a hollow structure. This forms an internal space 201c in which the latent heat storage material 201 is housed.

The storage member 211 is preferably made of a material with high rigidity. This prevents the shape of the storage member 211 from changing when the latent heat storage material 201 changes from a solid to a liquid. As a result, the cooling device 2 is characterized by minimal change in shape when the latent heat storage material 201 changes from a solid to a liquid.

The material constituting the housing member 211 includes, for example, at least one selected from the group consisting of resin materials, metal materials, and inorganic materials. The resin material includes at least one selected from the group consisting of polyethylene, polypropylene, polyester, polyurethane, polycarbonate, polyvinyl chloride, and polyamide. The metal material includes at least one selected from the group consisting of aluminum, stainless steel, copper, and silver. The inorganic material includes at least one selected from the group consisting of glass, porcelain, and ceramic. The material constituting the housing member 211 is preferably a resin material. This improves the ease of manufacturing and durability of the housing member 211.

The inlet 212 is connected to the top of the storage member 211.

The sealing member 213 seals the injection port 212.

The cooling device 2 is placed in close proximity to or in contact with the object to be cooled. This allows the object to be cooled at a temperature near the melting point of the latent heat storage material 201.

2.2 Manufacturing Method of Cooling Device FIGS. 7A to 7C are diagrams that schematically illustrate a manufacturing device 221 used to manufacture the cooling device 2 of the second embodiment.

As shown in Figures 7A to 7C, when the cooling device 2 is manufactured, the liquid latent heat storage material 201 is injected into the storage member 211 via the injection port 212 by a cylinder pump 231. The latent heat storage material 201 may also be injected into the storage member 211 by other methods. For example, the latent heat storage material 201 may be injected into the storage member 211 by a mono pump.

When the latent heat storage material 201 is injected into the storage member 211, as shown in Figure 7A, the tip of the filling hose 241 of the cylinder pump 231 is connected to the injection port 212. In addition, the tip of the suction hose 242 of the cylinder pump 231 is inserted into the latent heat storage material 201.

Next, as shown in Figure 7B, the piston 243 of the cylinder pump 231 is lowered. This causes the latent heat storage material 201 to be sucked up. The sucked-up latent heat storage material 201 is then sucked into the cylinder 244 of the cylinder pump 231 via the suction hose 242.

Next, as shown in Figure 7C, the piston 243 of the cylinder pump 231 is raised. This causes the latent heat storage material 201 to be discharged from inside the cylinder 244 of the cylinder pump 231. The discharged latent heat storage material 201 is injected into the storage member 211 via the filling hose 241. The amount of latent heat storage material 201 injected is not limited, but is preferably between 70% and 90% of the internal volume of the storage member 211.

Next, the injection port 212 is sealed with the sealing member 213. The injection port 212 is sealed with the sealing member 213, for example, by welding the sealing member 213 to the injection port 212. This causes the injection port 212 to be hermetically sealed by the sealing member 213. This makes it possible to prevent the latent heat storage material 201 from leaking from the accommodating member 211. The sealing member 213 is welded to the injection port 212 by ultrasonic welding, thermal welding, or the like.

The sealing member 213 may seal the injection port 212 by screwing the sealing member 213 into the injection port 212 as a screw plug. This allows the sealing member 213 to be a plug that can be opened and closed freely by hand.

The cooling device 2 is then placed in an environment with a temperature below the solidification temperature of the latent heat storage material 201. This causes the latent heat storage material 201 to solidify.

When the ice pack 2 is placed in a logistics packaging container, the latent heat storage material 201 is solidified before the ice pack 2 is placed in the logistics packaging container. However, if the temperature inside the logistics packaging container can be set to a temperature below the solidification start temperature of the latent heat storage material 201 in the initial stage of the logistics process, the latent heat storage material 201 may be solidified after the ice pack 2 is placed in the logistics packaging container. This allows the ice pack 2 to be started for use while the latent heat storage material 201 is still liquid.

3. Third embodiment 3.1 Logistics packaging container (food cooling device)
FIG. 8 is a cross-sectional view that schematically illustrates a logistics packaging container 3 according to the third embodiment.

The logistics packaging container 3 keeps the refrigerated item X cold. The logistics packaging container 3 is used to transport the refrigerated item X in a refrigerated state. The refrigerated item X is, for example, a frozen food that is kept cold at a temperature of -18°C or below. When the refrigerated item X is a frozen food, the logistics packaging container 3 also serves as a food cooling device that keeps the frozen food cold.

As shown in Figure 8, the logistics packaging container 3 comprises the ice pack 2 of the second embodiment and a logistics packaging container main body 301.

The logistics packaging container body 301 contains the cooling device 2 and the item to be cooled X.

The cooling device 2 sandwiches the item X to be refrigerated from above and below. This places at least a portion of the cooling device 2 in contact with the item X. This allows heat to be conducted from the item X to the cooling device 2 via the contact surface 2a between the item X and the cooling device 2. This allows the item X to be effectively kept cold. It also prevents heat flowing from the outside of the logistics packaging container 3 into the interior of the logistics packaging container 3 from affecting the item X. As a result, the cooling device 2 can keep the item X cold at a temperature near the melting point of the latent heat storage material 201. The logistics packaging container 3 is suitable for use in storing and transporting frozen foods that are kept cold at temperatures below -18°C.

The logistics packaging container 3 may also be equipped with an insulating member placed above the cooling device 2. This can improve the cooling performance of the logistics packaging container 3.

The shape, number, and orientation of the cooling devices 2 during use may vary depending on the shape and properties of the item to be cooled X.

4 Fourth embodiment 4.1 Cooling device Fig. 9 is a perspective view that schematically illustrates a cooling device 4 of the fourth embodiment. Fig. 10 is a cross-sectional view that schematically illustrates a cooling device 4 of the fourth embodiment. Fig. 10 illustrates a cross section at the position of the cutting line XI-XI drawn in Fig. 9.

The ice pack 4 is a film pack type ice pack.

As shown in Figures 9 and 10, the cooling device 4 comprises a latent heat storage material 401 and a cooling device main body 402.

The latent heat storage material 401 is the latent heat storage material of the first embodiment.

As shown in Figures 9 and 10, the cooling device main body 402 has multiple storage sections 411 and multiple joint sections 412.

Each of the multiple storage sections 411 liquid-tightly stores the latent heat storage material 401. The latent heat storage material 401 is stored in an internal space 411c formed in each of the multiple storage sections 411.

Each of the multiple storage sections 411 has a rectangular planar shape and an elliptical cross-sectional shape. Each of the multiple storage sections 411 may have a planar shape other than a rectangular planar shape, and may have a cross-sectional shape other than an elliptical cross-sectional shape.

The ice pack main body 402 has three storage compartments 411. The number of storage compartments 411 provided in the ice pack main body 402 may be increased or decreased. The number of storage compartments 411 provided in the ice pack main body 402 is increased or decreased depending on the size of the object to be kept cold. This allows the size of the ice pack 4 to be changed depending on the size of the object to be kept cold.

The latent heat storage material 401 may be one type of latent heat storage material, or two or more types of latent heat storage materials with different melting points. When two or more types of latent heat storage materials with different melting points are stored in multiple storage sections 411, multiple items to be kept cold at different temperatures can be kept cold simultaneously.

Each of the multiple joints 412 connects two adjacent storage sections 411 included in the multiple storage sections 411. Each of the multiple joints 412 has a joint function that allows the two storage sections 411 to move. By providing the ice pack 4 with multiple joints 412, the ice pack 4 can be given a shape that conforms to the object to be cooled, even when the latent heat storage material 401 is solid. This allows the ice pack 4 to come into contact with the object over a wide area, even if the object has a complex shape. This allows the object to be effectively cooled, even if the object has a complex shape.

As shown in Figure 10, the ice pack body 402 comprises two film members 421. The two film members 421 are joined to each other at multiple joints 431 to form multiple joint sections 412, and the remaining sections are not joined to each other to form multiple storage sections 411.

The film member 421 is made of a material that can suppress leakage and volatilization of the latent heat storage material 401. The film member 421 is also made of a material that can be bonded to other films. The film member 421 is also made of a flexible material that can provide joint functionality to the multiple joints 412.

The material constituting the film member 421 includes, for example, at least one selected from the group consisting of polyethylene, polypropylene, polyamide, and polyester. The material constituting the film member 421 may be a single material or a combination of two or more materials.

The film member 421 may be a single-layer film or a multi-layer film. Preferably, the film member 421 is a multi-layer film including a low-density polyethylene resin layer and a polyamide resin layer. When the film member 421 is a multi-layer film, two film members 421 are stacked so that the two low-density polyethylene resin layers included in each of the two film members 421 are in contact with each other. Furthermore, the contact surfaces of the two low-density polyethylene resin layers are thermocompression-bonded to each other. This allows multiple joints 412 to be formed.

The film member 421 may include a substrate and a thin film disposed on the substrate. The material constituting the thin film may include, for example, at least one selected from the group consisting of aluminum and silicon dioxide. This can improve the durability and barrier properties of the film member 421.

The cooling device 4 may be provided with a temperature indicator sticker attached to the film member 421 that indicates the temperature. This makes it possible to recognize the temperature of the cooling device 4.

The cooling device 4 may have a so-called pack-in-pack structure. When the cooling device 4 has a pack-in-pack structure, the cooling device 4 includes a film that wraps the film member 421. This improves the physical strength, feel, and thermal insulation of the cooling device 4.

The cooling device 4 may be attached to a fixing jig for fixing the cooling device 4 to the object to be cooled. The fixing jig may be, for example, a supporter, towel, bandage, etc.

4.2 Manufacturing Method of the Cooling Device FIG. 11 is a diagram that schematically illustrates a manufacturing device 441 used to manufacture the cooling device 4 of the fourth embodiment.

Manufacturing device 441 is a so-called vertical pillow packaging machine, which is also used for packaging food.

As shown in Figure 11, when the cooling device 4 is manufactured, the latent heat storage material 401 stored in the constant temperature bath 451 is transported to the mixing bath 452.

The latent heat storage material 401 is then transported to the mixing tank 452 and mixed by the mixer 453.

Next, two films 454 are unwound from a film roll (not shown).

Next, both ends of the two films 454 extending in the longitudinal direction are joined together by the former section 455.

Next, both ends of the two joined films 454 are heat-pressed together by the vertical seal section 456. This forms a cylindrical object from the two films 454.

Next, the two films 454 that make up the cylindrical object are heat-pressed together by the horizontal sealing section 457 along a pressure-bonding line extending in the minor axis direction of the two films 454.

Next, the pump 459 is operated, which injects the stirred latent heat storage material 401 into the cylindrical object formed by the two films 454.

The two films 454 that make up the cylindrical object are then heat-pressed again by the horizontal seal section 457 along a pressure line extending in the minor axis direction of the two films 454. This forms the storage section 411 and the joint section 412. The formed storage section 411 contains the latent heat storage material 401.

5. Fifth embodiment 5.1 Logistics packaging container (food cooling device)
FIG. 12 is a cross-sectional view that schematically illustrates a logistics packaging container 5 according to the fifth embodiment.

The logistics packaging container 5 keeps the refrigerated item X cold. The logistics packaging container 5 is used to transport the refrigerated item X in a refrigerated state. The refrigerated item X is, for example, a frozen food that is kept cold at a temperature of -18°C or below. When the refrigerated item X is a frozen food, the logistics packaging container 5 also serves as a food cooling device that keeps the frozen food cold.

As shown in Figure 12, the logistics packaging container 5 comprises the cooling device 4 of the fourth embodiment and a logistics packaging container main body 501.

The logistics packaging container body 501 contains the cooling device 4 and the item to be cooled X.

The cooling device 4 covers the object X to be refrigerated from above. This brings at least a portion of the cooling device 4 into contact with the object X. This allows heat to be conducted from the object X to the cooling device 4 via the contact surface 4a between the object X and the cooling device 4. This allows the object X to be effectively kept cold. It also prevents heat flowing from the outside of the logistics packaging container 5 into the interior of the logistics packaging container 5 from affecting the object X. As a result, the cooling device 4 can keep the object X cold at a temperature near the melting point of the latent heat storage material 401. For this reason, the cooling device 4 is suitable for use in storing and transporting frozen foods that are kept cold at temperatures below -18°C.

The shape, number, and orientation of the cooling devices 4 during use may vary depending on the shape and properties of the item to be cooled X.

5.2 Modification FIG. 13 is a cross-sectional view that schematically illustrates a logistics packaging container 5A that is a modification of the fifth embodiment.

The logistics packaging container 5A differs from the logistics packaging container 5 in that it includes the ice pack 2 of the second embodiment in addition to the ice pack 4 of the fourth embodiment. The ice pack 2 is placed between the refrigerated item X and the bottom surface 510a of the logistics packaging container body 501. This prevents heat from flowing into the refrigerated item X via the bottom surface 510a of the logistics packaging container body 501.

As mentioned above, the cooling device 2 has the characteristic that the shape of the latent heat storage material 201 changes little when it changes from a solid to a liquid. Therefore, in the logistics packaging container 5A, the item to be refrigerated X can be stably placed on top of the cooling device 2.

6 Sixth Embodiment 6.1 Cooling Device Fig. 14 is a plan view that schematically illustrates a cooling device 6 of a sixth embodiment. Fig. 15 is a cross-sectional view that schematically illustrates a cooling device 6 of the sixth embodiment.

The ice pack 6 is a so-called blister pack type ice pack.

As shown in Figures 14 and 15, the cooling device 6 comprises a latent heat storage material 601 and a cooling device main body 602.

The latent heat storage material 601 is the latent heat storage material of the first embodiment.

As shown in Figures 14 and 15, the cooling device main body 602 has multiple storage sections 611 and multiple joint sections 612.

Each of the multiple storage sections 611 liquid-tightly stores a latent heat storage material 601. The latent heat storage material 601 is stored in an internal space 611c formed in each of the multiple storage sections 611.

Each of the multiple storage sections 611 has a rectangular planar shape and a trapezoidal cross-sectional shape. Each of the multiple storage sections 611 may have a planar shape other than a rectangular planar shape, and may have a cross-sectional shape other than a trapezoidal cross-sectional shape.

The ice pack main body 602 has six storage compartments 611. The number of storage compartments 611 provided in the ice pack main body 602 may be increased or decreased. The number of storage compartments 611 provided in the ice pack main body 602 is changed depending on the size of the object to be kept cold. This allows the size of the ice pack 602 to be changed depending on the size of the object to be kept cold.

The latent heat storage material 601 may be one type of latent heat storage material, or two or more types of latent heat storage materials with different melting points. When two or more types of latent heat storage materials with different melting points are stored in multiple storage sections 611, multiple items to be kept cold at different temperatures can be kept cold simultaneously.

If the object to be refrigerated has a can-like shape, the contact surface 611a of the storage section 611 may be a concave surface that fits the convex surface of the object to be refrigerated. If the object to be refrigerated has a tapered shape, the thickness of the storage section 611 may vary along the longitudinal direction of the storage section 611.

Each of the multiple joints 612 connects two adjacent storage sections 611 included in the multiple storage sections 611. Each of the multiple joints 612 has a joint function that allows the two storage sections 611 to move. By providing the cooling device 6 with multiple joints 612, the cooling device 6 can be given a shape that conforms to the object to be kept cold, even when the latent heat storage material 601 is solid. This allows the cooling device 6 to come into contact with the object over a wide area, even if the object has a complex shape. This allows the object to be kept cold effectively, even if the object has a complex shape.

As shown in FIG. 15, the cooling device main body 602 includes a storage member 621 and a sealing member 622. The storage member 621 and the sealing member 622 are joined to each other at multiple joints 631 to form multiple joints 612, and are not joined to each other at the remaining portions to form multiple storage sections 611.

As shown in FIG. 15, the storage member 621 has multiple recesses 641. The sealing member 622 has a flat plate shape. The multiple recesses 641, together with the sealing member 622, form multiple storage sections 611.

The housing member 621 is made of a material hard enough to maintain the shape of the recess 641. The housing member 621 and sealing member 622 are made of a material that can prevent leakage and volatilization of the latent heat storage material 601. The housing member 621 and sealing member 622 are also made of a material that can be joined to each other. The housing member 621 and sealing member 622 are also made of a flexible material that can provide joint functionality to the multiple joints 612.

The material constituting the storage member 621 includes, for example, at least one selected from the group consisting of polyethylene, polypropylene, polyamide, polyester, polycarbonate, and polyvinyl chloride. The material constituting the storage member 621 may be a single material or a combination of two or more materials.

The housing member 621 preferably has a thickness of 100 μm or more and 1000 μm or less. This allows the housing member 621 to be flexible, thereby providing joint functionality to the multiple joint portions 612.

The material constituting the sealing member 622 includes, for example, at least one selected from the group consisting of polyethylene, polypropylene, polyamide, and polyester. The material constituting the sealing member 622 may be a single material or a combination of two or more materials.

The sealing member 622 preferably has a thickness of 50 μm or more and 100 μm or less. This allows the sealing member 622 to be flexible, thereby providing joint functionality to the multiple joint portions 612.

The housing member 621 and the sealing member 622 may be single-layer or multi-layer members. The housing member 621 and the sealing member 622 are preferably multi-layer members comprising a low-density polyethylene resin layer and a polyamide resin layer. When the housing member 621 and the sealing member 622 are multi-layer members, the housing member 621 and the sealing member 622 are stacked so that the two low-density polyethylene resin layers provided in the housing member 621 and the sealing member 622 respectively come into contact with each other. Furthermore, the contact surfaces of the two low-density polyethylene resin layers are thermocompression-bonded to each other. This allows multiple joints 612 to be formed.

At least one of the housing member 621 and the sealing member 622 may include a substrate and a thin film disposed on the substrate. The material constituting the thin film may include at least one selected from the group consisting of aluminum and silicon dioxide. This can improve the durability and barrier properties of the member.

The cooling device 6 may be provided with a temperature-indicating sticker attached to at least one of the housing member 621 and the sealing member 622, which indicates the temperature. This makes it possible to determine the temperature of the cooling device 6.

The storage member 621 and the sealing member 622 may have fixing portions for maintaining the cylindrical shape of the cooling device 6. This allows the cooling device 6 to surround the object to be cooled when the cooling device 6 is brought close to or into contact with the object. The fixing portions may include, for example, hook-and-loop fasteners provided on the surface 621a of the storage member 621 and the surface 622a of the sealing member 622.

6.2 Modifications Fig. 16 is a perspective view that schematically illustrates a human body cooling apparatus 6A that is a modification of the sixth embodiment. Fig. 17 is a cross-sectional view that schematically illustrates a human body cooling apparatus 6A that is a modification of the sixth embodiment.

The cooling device 6A differs from the cooling device 6 in that it includes a cooling device support 651.

The cooling device support 651 has a cylindrical shape with a bottom. One end of the cooling device support 651 is open. An internal space 651c that houses the cooling device 6 is formed in the cooling device support 651. The cooling device 6 is deformed so that the housing member 621 is positioned radially inward and the sealing member 622 is positioned radially outward. By including the cooling device support 651, the cooling device 6A has a cylindrical shape and can stand on its own.

The cooling device support 651 is preferably made of a material that has thermal insulation properties and can prevent heat exchange between the outside of the cooling device support 651 and the inside of the cooling device support 651.

The material constituting the cooling device support 651 includes, for example, at least one selected from the group consisting of foamed polyethylene, foamed urethane, and chloroprene rubber (foamed rubber).

As shown in Figure 17, when the cooling device 6A is in use, a can- or bottle-shaped object to be kept cold X is inserted into the cylindrical space 600c surrounded by the cooling device support 651. This allows the cooling device 6A to be brought close to or into contact with the object to be kept cold X. This allows the object to be kept cold at a temperature near the melting point of the latent heat storage material 601.

The cooling device support 651 is preferably made of an elastic material. This allows the cooling device support 651 to elastically deform according to the diameter of the object to be kept cold X. This allows the cooling device support 651 to be pressed against the object to be kept cold X.

6.3 Manufacturing Method of Cooling Device FIGS. 18A to 18D are cross-sectional views that schematically illustrate intermediate products obtained when the cooling device 6 of the sixth embodiment is manufactured.

When the cooling device 6 is manufactured, as shown in Figure 18A, a hard film 671, which serves as a precursor to the storage member 621, is placed on a mold 661 in which a groove 661g having a trapezoidal cross-sectional shape is formed.

Next, as shown in Figure 18B, the shape of the groove 661g formed in the mold 661 is transferred to the hard film 671 by vacuum molding, press working, or the like. This forms the housing member 621.

Next, as shown in Figure 18C, the liquid latent heat storage material 601 is injected into the recess 641 of the housing member 621 using a pump or the like.

Next, as shown in Figure 18D, the sealing member 622 is placed on the housing member 621. The contact surfaces of the housing member 621 and the sealing member 622 are then thermocompressed together to form the housing portion 611 and the joint portion 612.

7 Seventh embodiment 7.1 Logistics packaging container (food cooling device)
FIG. 19 is a cross-sectional view that schematically illustrates a logistics packaging container 7 according to the seventh embodiment.

The logistics packaging container 7 keeps the refrigerated item X cold. The logistics packaging container 7 is used to transport the refrigerated item X in a refrigerated state. The refrigerated item X is, for example, a frozen food that is kept cold at a temperature of -18°C or below. When the refrigerated item X is a frozen food, the logistics packaging container 7 also serves as a food cooling device that keeps the frozen food cold.

As shown in Figure 19, the logistics packaging container 7 comprises the cooling device 6 of the sixth embodiment and a logistics packaging container main body 701.

The logistics packaging container body 701 contains the cooling device 6 and the item to be cooled X.

The cooling device 6 covers the object X to be refrigerated from above. This places at least a portion of the cooling device 6 in contact with the object X. This allows heat to be conducted from the object X to the cooling device 6 via the contact surface 6a between the object X and the cooling device 6. This allows the object X to be effectively kept cold. It also prevents heat flowing from the outside of the logistics packaging container 7 into the interior of the logistics packaging container 7 from affecting the object X. As a result, the cooling device 6 can keep the object X cold at a temperature near the melting point of the latent heat storage material 601. For this reason, the cooling device 6 is suitable for use in storing and transporting frozen foods that must be maintained at temperatures below -18°C.

The logistics packaging container 7 may also be equipped with an insulating member placed above the cooling device 6. This can improve the cooling performance of the logistics packaging container 7.

In the logistics packaging container 7, the surface 621a of the storage member 621 and the bottom surface 701a of the logistics packaging container body 701 may be secured to each other using a hook-and-loop fastener or the like.

The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that provides the same effects, or a configuration that can achieve the same purpose.

2. Cooling device, 3. Logistics packaging container, 4. Cooling device, 5. Logistics packaging container, 5A. Logistics packaging container, 6. Cooling device, 6A. Cooling device, 7. Logistics packaging container, 201. Phase change material, 202. Cooling device body, 301. Logistics packaging container body, 401. Phase change material, 402. Cooling device body, 411. Storage section, 412. Joint section, 501. Logistics packaging container body, 601. Phase change material, 602. Cooling device body, 611. Storage section, 612. Joint section, 621. Storage member, 622. Sealing member, 701. Logistics packaging container body

Claims (1)

The composition comprises ammonium chloride, ammonium bromide, water, and a water-insoluble supercooling inhibitor, wherein the total of 3.5 to 22.5 parts by weight of the ammonium chloride, 6.5 to 25.5 parts by weight of the ammonium bromide, and the water is 100 parts by weight ;
The composition contains 1 to 10 parts by weight of the water-insoluble supercooling inhibitor,
the water-insoluble supercooling inhibitor is any one of calcium carbonate, aluminum oxide, and activated carbon;
Has a melting temperature in the range of -18°C to -20°C
Latent heat storage material.