Latent heat storage materials, cooling devices, logistics packaging containers, and food cooling devices

Abstract

Provided is a latent heat storage material that can keep an item to be kept cold, such as a frozen food product, at a temperature of -18°C or less for a long time, and can reduce the power consumption required at the time of solidification. This latent heat storage material includes 6 parts by weight to 29 parts by weight of ammonium chloride, 6 parts by weight to 29 parts by weight of urea, and 42 parts by weight to 88 parts by weight of water, wherein the ammonium chloride, the urea, and the water total 100 parts by weight, and the main melting point is within the range -18°C to -21°C.

Description

[Technical Field]

[0001] This disclosure relates to a latent heat storage material, a cooling device, a logistics packaging container, and a food cooling device. This application claims priority to Japanese Patent Application No. 2020-202086, filed on December 4, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] When frozen foods are transported, in many cases, the frozen foods are packed in a distribution container, and the distribution container containing the frozen foods is transported.

[0003] 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.

[0004] However, in recent years, there has been a shortage of liquefied carbon dioxide, the raw material for dry ice, with the shortage particularly severe in the summer. Demand for liquefied carbon dioxide is diverse, and it is natural that priority should be given to supplying it to medical facilities where life is at stake. For this reason, in the logistics field, latent heat storage materials with a melting point of around -25°C are increasingly being used as a substitute for dry ice.

[0005] The ice pack described in Patent Document 1 contains a water-soluble compound with a freezing point depressing effect and water (paragraph 0006). The water-soluble compound with a freezing point depressing effect is used in combination with an inorganic salt of a monovalent cation and urea (paragraph 0042). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-65560 Summary of the Invention [Problem to be solved by the invention]

[0007] Phase change materials must be solidified before use. Phase change materials with a melting point around -25°C, which have been the primary alternative to dry ice, require freezers set at temperatures below -35°C to solidify. Generally, the lower the freezers' set temperature, the greater the amount of electricity consumed. Logistics requires a large amount of phase change material, which requires a huge amount of energy for solidification. However, as mentioned above, frozen foods require different temperatures, and not all foods require phase change materials with a melting point around -25°C. By selecting a phase change material with a melting point as close as possible to the required freezing temperature—i.e., by using a phase change material with a higher melting point than conventional materials—the required freezers' set temperature can be increased, thereby reducing power consumption.

[0008] Furthermore, latent heat storage materials with melting points between -25°C and -20°C are often primarily composed of water, but the latent heat of these materials is low compared to the 333 J / g latent heat required for ice melting. For example, a latent heat storage material containing sodium chloride and water and having a eutectic composition has a melting point of approximately -21°C, but the latent heat of this material is low, at approximately 210 J / g. For this reason, latent heat storage materials with melting points between -25°C and -20°C generally have a short cooling time. In particular, when the melting point of the latent heat storage material is -25°C, the difference between the temperature of the environment surrounding the latent heat storage material and the melting point of the latent heat storage material becomes large, resulting in a large amount of heat absorption per unit time by the latent heat storage material, which accelerates wear of the latent heat storage material and further shortens the cooling time of the latent heat storage material.

[0009] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a latent heat storage material that can keep an object to be refrigerated, such as a frozen food, at a temperature of −18°C or lower for a long period of time and that can reduce the power consumption required for solidification. [Means for solving the problem]

[0010] The latent heat storage material of the first embodiment of the present disclosure contains 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water, the total amount of the ammonium chloride, urea, and water being 100 parts by weight, and has a main melting point in the range of -18°C to -21°C.

[0011] A human cooling device according to a second embodiment of the present disclosure includes the latent heat storage material according to the first embodiment of the present disclosure, and a human cooling device main body that accommodates the latent heat storage material in a liquid-tight manner.

[0012] A logistics packaging container and a food cooling device according to a third embodiment of the present disclosure include the cooling device according to the second embodiment of the present disclosure.

[0013] A human cooling device according to a fourth embodiment of the present disclosure includes the latent heat storage material according to the first embodiment of the present disclosure, and a human cooling device main body including a plurality of storage sections and a plurality of joint sections.

[0014] A logistics packaging container and a food cooling device according to a fifth embodiment of the present disclosure include the cooling device according to the fourth embodiment of the present disclosure.

[0015] A human cooling device according to a sixth embodiment of the present disclosure includes the latent heat storage material according to the first embodiment of the present disclosure, and a human cooling device main body including a plurality of storage sections and a plurality of joint sections.

[0016] A logistics packaging container and a food cooling device according to a seventh embodiment of the present disclosure include the cooling device according to the sixth embodiment of the present disclosure. [Effects of the Invention]

[0017] According to the present disclosure, it is possible to provide a latent heat storage material that can keep items to be refrigerated, such as frozen foods, at temperatures of -18°C or below for long periods of time and that can reduce the power consumption required during solidification. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a table showing the composition of latent heat storage materials according to examples and comparative examples. [Figure 2]FIG. 2 is a diagram illustrating a method for measuring the melting start temperature and latent heat quantity of the latent heat storage materials according to the examples and comparative examples. [Figure 3] 1 is a diagram illustrating a method for determining the main melting point and cold insulation time of a latent heat storage material according to an example and a comparative example. FIG. [Figure 4] 1 is a diagram showing the melting behavior of latent heat storage materials according to Example 1 and Comparative Example 1. FIG. [Figure 5] 1 is a diagram showing the melting behavior of the latent heat storage materials according to Examples 1, 2, and 3. FIG. [Figure 6] 1 is a diagram showing the melting behavior of the latent heat storage materials of Example 1 and Comparative Examples 2 and 3. FIG. [Figure 7] FIG. 1 is a diagram showing the melting behavior of the latent heat storage materials of Examples 4 and 5 and Comparative Examples 2 and 3. [Figure 8] FIG. 2 is a diagram showing the solidification behavior of the latent heat storage materials according to Example 1 and Examples 6 to 9. [Figure 9] FIG. 10 is a longitudinal cross-sectional view schematically illustrating a human body cooling device according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view schematically illustrating a human body cooling device according to a second embodiment. [Figure 11A] FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. [Figure 11B] FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. [Figure 11C] FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the second embodiment. [Figure 12] FIG. 10 is a cross-sectional view schematically illustrating a logistics packaging container according to a third embodiment. [Figure 13] FIG. 10 is a perspective view schematically illustrating a human body cooling device according to a fourth embodiment. [Figure 14] FIG. 10 is a cross-sectional view schematically illustrating a human body cooling device according to a fourth embodiment. [Figure 15] FIG. 10 is a diagram schematically illustrating a manufacturing device used to manufacture the cooling device of the fourth embodiment. [Figure 16] FIG. 10 is a cross-sectional view schematically illustrating a logistics packaging container according to a fifth embodiment. [Figure 17]FIG. 13 is a cross-sectional view schematically illustrating a logistics packaging container according to a modified example of the fifth embodiment. [Figure 18] FIG. 13 is a plan view schematically illustrating a human body cooling device according to a sixth embodiment. [Figure 19] FIG. 10 is a cross-sectional view schematically illustrating a human body cooling device according to a sixth embodiment. [Figure 20] FIG. 13 is a perspective view schematically illustrating a human body cooling device according to a modified example of the sixth embodiment. [Figure 21] FIG. 13 is a cross-sectional view schematically illustrating a human body cooling device according to a modified example of the sixth embodiment. [Figure 22A] FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling apparatus of the sixth embodiment is manufactured. [Figure 22B] FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling apparatus of the sixth embodiment is manufactured. [Figure 22C] FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling apparatus of the sixth embodiment is manufactured. [Figure 22D] FIG. 13 is a cross-sectional view schematically illustrating an intermediate product obtained when the human body cooling apparatus of the sixth embodiment is manufactured. [Figure 23] FIG. 13 is a cross-sectional view schematically illustrating a logistics packaging container according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0020] 1. First embodiment 1.1 Composition of latent heat storage material The latent heat storage material of the first embodiment, when brought into close proximity to or contact with an object to be insulated in a solidified state, keeps the object cool at a temperature near its primary melting point. The latent heat storage material continues to keep the object cool at a temperature near its primary melting point until it completely melts.

[0021] The latent heat storage material of the first embodiment contains 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water. Desirably, the latent heat storage material contains 14 to 16 parts by weight of ammonium chloride, 15 to 18 parts by weight of urea, and 66 to 71 parts by weight of water. The total amount of ammonium chloride, urea, and water is 100 parts by weight.

[0022] 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 a liquid state, the latent heat storage material is composed of a mixed aqueous solution of ammonium chloride and urea, but in a solid state, it is composed mainly of a eutectic of ammonium chloride, urea, and ice. Therefore, when the latent heat storage material is solidified, a eutectic of mainly ammonium chloride, urea, 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.

[0023] The eutectic of ammonium chloride and ice has a eutectic point at approximately -15°C. The eutectic of urea and ice also has a eutectic point at approximately -12°C. On the other hand, it was found that the eutectic of ammonium chloride, urea, and ice has a eutectic point at approximately -20°C, lower than either of the eutectics. Furthermore, ammonium chloride, an ionic substance, dissociates into cations (ammonium ions) and anions (chloride ions) when dissolved in water. Therefore, if other ionic substances whose cations and anions are different from ammonium chloride are contained, different inorganic salts are formed between the other cations and anions dissociated from the other ionic substances, inhibiting the formation of a eutectic between ammonium chloride and ice. However, urea, a molecular substance, hardly dissociates into ions and is therefore unlikely to produce other substances. Therefore, by forming only a eutectic of ammonium chloride, urea, and ice, the latent heat storage material has a single eutectic point at -20°C. Therefore, the latent heat storage material of the first embodiment has a composition close to a eutectic composition, and therefore has a main melting point close to −20° C., specifically in the range of −18° C. to −21° C. Therefore, the latent heat storage material can keep an object refrigerated at a temperature of −18° C. or lower.

[0024] The latent heat storage material of the first embodiment has a primary melting point of -18°C to -21°C. Therefore, the difference between the temperature of the environment surrounding the latent heat storage material and the primary melting point of the latent heat storage material is smaller than that of a storage material having a melting point of -25°C. Therefore, the amount of heat absorbed by the latent heat storage material per unit time when it melts is small. Furthermore, the latent heat storage material has a composition close to the eutectic composition of a eutectic consisting of ammonium chloride, urea, and ice, and therefore has a large amount of latent heat. For these reasons, the latent heat storage material has a long cooling time.

[0025] However, if the latent heat storage material has a composition outside the above-mentioned range, the amount of solidification components other than the eutectic of ammonium chloride, urea, and ice formed when the latent heat storage material solidifies will be large. This makes it difficult to obtain a latent heat storage material with a primary melting point between −18°C and −21°C and a large amount of latent heat. For example, if the latent heat storage material contains less than 6 parts by weight of ammonium chloride or less than 6 parts by weight of urea, the latent heat storage material obtained will have a latent heat amount less than half that of the eutectic composition. In other words, the cooling time will be significantly shortened. Furthermore, if the latent heat storage material contains more than 29 parts by weight of ammonium chloride or more than 29 parts by weight of urea, the latent heat storage material obtained will have a small amount of latent heat and a primary melting point below −21°C. When the primary melting point is below -21°C, the difference between the temperature of the environment surrounding the latent heat storage material and the primary melting point of the latent heat storage material becomes larger, and the amount of heat absorbed per unit time becomes larger compared to latent heat storage materials having a primary melting point in the range of -18°C to -21°C. In other words, even if a latent heat storage material whose primary melting point is below -21°C and a latent heat storage material whose primary melting point is in the range of -18°C to -21°C both have the same latent heat amount, the latent heat storage material whose primary melting point is below -21°C will have a shorter cold retention time.

[0026] The latent heat storage material of the first embodiment preferably contains a supercooling inhibitor. The supercooling inhibitor is dissolved or dispersed in water. By including the supercooling inhibitor, the phenomenon in which the latent heat storage material supercools and the solidification start temperature drops when the latent heat storage material solidifies can be suppressed. When the supercooling inhibitor dissolves in water, the solubility of the supercooling inhibitor decreases and saturates during the temperature drop when the latent heat storage material solidifies, and the supercooling inhibitor solidifies, thereby exhibiting the suppression effect. Therefore, the latent heat storage material can be solidified, for example, in a widely used freezer at -25°C.

[0027] The supercooling inhibitor desirably includes at least one selected from the group consisting of ammonium aluminum sulfate dodecahydrate, calcium carbonate, aluminum oxide, and activated carbon.

[0028] The weight of the supercooling inhibitor is desirably 0.1 to 10 parts by weight per 100 parts by weight of the total of ammonium chloride, urea, and water.

[0029] The latent heat storage material of the first embodiment may contain components other than those described above. The components other than those described above include, for example, at least one selected from the group consisting of a thickener, an antibacterial agent, and a pigment.

[0030] <Examples and Comparative Examples of the First Embodiment> The latent heat storage materials according to the examples and comparative examples were prepared by mixing water, an inorganic salt (e.g., ammonium chloride, sodium chloride, etc.), a main agent containing urea, etc., and a supercooling inhibitor in the weight ratios shown in the table of Fig. 1, and dissolving the inorganic salt, urea, supercooling inhibitor, etc. in the water. The latent heat storage materials were prepared so that the total amount of the main agent was 100 parts by weight.

[0031] FIG. 1 also shows the results of properties such as latent heat value, melting start temperature, main melting point, and cooling time for the latent heat storage materials according to the examples and comparative examples.

[0032] FIG. 2 is a diagram illustrating a method for measuring the melting start temperature and the amount of latent heat of the latent heat storage material of the first embodiment.

[0033] When the melting initiation temperature and latent heat quantity of the latent heat storage material of the first embodiment are measured, a DSC curve 10 is obtained by differential scanning calorimetry (DSC) for the latent heat storage material, as shown in Fig. 2. 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 of intersection 16 between line 13, which is a linear extrapolation of low-temperature side 12 of melting peak 11 included in DSC curve 10, and line 15, which is a linear extrapolation of low-temperature side baseline 14 included in DSC curve 10. The latent heat quantity is determined as the area of ​​latent heat region 17 surrounded by melting peak 11 and line 15, divided by the weight of the latent heat storage material.

[0034] The melting characteristics of the latent heat storage materials according to the examples and comparative examples were evaluated. A thermocouple was inserted into 40 g of the latent heat storage materials according to the examples and comparative examples, and the temperature of each latent heat storage material was measured when it melted. Specifically, each latent heat storage material was solidified at -35°C, and then heated at a rate of 0.25°C / min, and the temperature change over time of each latent heat storage material was measured at 1-minute intervals using the thermocouple.

[0035] The main melting point and cooling time were obtained from the results of measuring the melting characteristics described above.

[0036] FIG. 3 is a diagram illustrating a method for determining the main melting point and cold insulation time of the latent heat storage material according to the first embodiment.

[0037] In the time-dependent change in temperature of the latent heat storage material in Figure 3, when the average value of the rate of temperature change of the latent heat storage material between the measurement point immediately before the measurement point and the measurement point in question and the rate of temperature change of the latent heat storage material between the measurement point in question and the measurement point immediately after the measurement point is calculated for each measurement point at one-minute intervals, the longest continuous section of consecutive measurement points where the average value is less than 0.15 ° C / min, which is smaller than the ambient temperature rise rate of 0.25 ° C / min, is the main melting region. The minimum temperature of the main melting region is the temperature of the latent heat storage material at the first measurement point in the main melting region. The maximum temperature of the main melting region is the temperature of the latent heat storage material at the last measurement point in the main melting region. The intermediate value between the minimum temperature and the maximum temperature in the main melting region is the main melting point.

[0038] The cold insulation time is the time during which the temperature of the latent heat storage material is in the range of -18°C to -21°C, and is the time during which cold insulation within the temperature range is possible using the latent heat storage material.

[0039] The results of the melting characteristics of the latent heat storage materials of Example 1 and Comparative Example 1 are shown in Figure 4, the results of the melting characteristics of the latent heat storage materials of Examples 1, 2 and 3 are shown in Figure 5, the results of the melting characteristics of the latent heat storage materials of Example 1 and Comparative Examples 2 and 3 are shown in Figure 6, and the results of the melting characteristics of the latent heat storage materials of Examples 4 and 5 and Comparative Examples 2 and 3 are shown in Figure 7. The horizontal axes of Figures 4 to 7 indicate the time elapsed since the temperature started to rise from -35°C.

[0040] 4, it can be seen that the latent heat storage material of Example 1 completely melted and the temperature rose sharply after about 2.9 hours, whereas the latent heat storage material of Comparative Example 1 completely melted and the temperature rose sharply after about 2.6 hours, indicating that the material melted in a short time. The cold retention time was about 1.9 hours for Example 1 and about 1.6 hours for Comparative Example 1. That is, the latent heat storage material of Example 1 contains 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water, and by having a composition in which the total of the ammonium chloride, urea, and water is 100 parts by weight, the latent heat storage material can retain cold for a longer period of time than the latent heat storage material of Comparative Example 1.

[0041] 5, it was found that the latent heat storage materials of Examples 2 and 3 have a long cold retention time equivalent to that of the latent heat storage material of Example 1. That is, if the latent heat storage material is made of 14 to 16 parts by weight of ammonium chloride, 15 to 18 parts by weight of urea, and 66 to 71 parts by weight of water, which is the desirable composition range, almost only a eutectic is formed during solidification, and a large amount of latent heat is obtained, so that it can be kept cold for a long time.

[0042] 6, the latent heat storage material of Comparative Example 2 maintained cold storage time less than half that of the latent heat storage material of Example 1. Furthermore, the latent heat storage material of Comparative Example 3 had a main melting point below -18°C to -21°C, and therefore had a short cold storage time. In other words, with a composition outside the above-mentioned range, the amount of latent heat is significantly reduced, or the amount of latent heat is reduced and the main melting point is below -18°C to -21°C, so the cold storage time is significantly reduced and it becomes difficult to keep the material cold at -18°C or below.

[0043] 7, it can be seen that the latent heat storage material of Comparative Example 2 has an extremely short cooling time compared to the latent heat storage material of Example 4. This is thought to be because the concentration of ammonium chloride becomes extremely low, which reduces the amount of eutectic formed from ammonium chloride and ice, resulting in a low latent heat value.

[0044] Furthermore, it can be seen that the latent heat storage material of Comparative Example 3 has a shorter cold retention time than the latent heat storage material of Example 5. This is thought to be because too much urea inhibits the formation of a eutectic with ammonium chloride and ice, resulting in a lower main melting point and a lower latent heat value, as shown in Figure 1. A lower main melting point means that melting components with a lower temperature than the desired temperature for cold retention are generated during solidification. However, since the temperature difference between the lower temperature melting components and the surrounding ambient temperature is greater, the amount of heat absorbed per unit time is greater, causing faster melting and resulting in a shorter cold retention time. Therefore, it is preferable that the main melting point of the latent heat storage material be -18°C to -21°C.

[0045] From the above, it is believed that the shorter cooling time in Comparative Examples 2 and 3 compared to Examples 4 and 5 is due to the influence of the concentrations of ammonium chloride and urea in the latent heat storage material. Specifically, if the concentrations deviate from the range of 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water, the cooling time at temperatures between -18°C and -21°C will be shortened. For example, it is difficult to keep objects to be cooled, such as frozen foods, at temperatures below -18°C, and sufficient cooling effect will not be achieved. Therefore, it is clear that it is preferable to adjust the concentration range of the latent heat storage material to 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water.

[0046] Furthermore, the solidification characteristics of the latent heat storage materials according to Example 1 and Examples 6 to 9 were evaluated. A thermocouple was placed in 40 g of each latent heat storage material, and the temperature change over time during solidification of each latent heat storage material was measured. Specifically, each latent heat storage material was placed in a refrigerator with an ambient temperature of -25°C, and the ambient temperature was maintained at -25°C, and the temperature change over time during solidification of the latent heat storage material was measured.

[0047] The results regarding the coagulation properties of Example 1 and Examples 6 to 9 are shown in FIG.

[0048] As can be seen from Figure 8, the latent heat storage material of Example 1 ceased supercooling after the temperature dropped below -23°C, and solidification began, and heat generation due to solidification was observed. On the other hand, the latent heat storage materials of Examples 6 to 9, to which a supercooling inhibitor was added, began solidification quickly with almost no supercooling, and heat generation due to solidification was observed. In other words, by adding a supercooling inhibitor, the latent heat storage material can be quickly solidified even when cooled to -25°C, which is in the range of its main melting point, near -18°C to -21°C. Compared to the latent heat storage material of Example 1, to which a supercooling inhibitor was not added, the latent heat storage materials of Examples 6 to 9, to which a supercooling inhibitor was added, can be provided with cold insulation performance while saving energy.

[0049] 2. Second embodiment 2.1 Cooling devices Fig. 9 is a longitudinal sectional view that schematically illustrates the human body cooling apparatus 2 of the second embodiment. Fig. 10 is a transverse sectional view that schematically illustrates the human body cooling apparatus 2 of the second embodiment.

[0050] The cooling device 2 keeps an object to be cooled. The object to be cooled is, for example, frozen food that is kept at a temperature of −18° C. or lower. The cooling device 2 is a so-called blown container type cooling device.

[0051] As shown in FIGS. 9 and 10, the human body cooling tool 2 includes a latent heat storage material 201 and a human body cooling tool main body 202.

[0052] The latent heat storage material 201 is the latent heat storage material of the first embodiment.

[0053] The ice pack body 202 liquid-tightly accommodates the latent heat storage material 201. The latent heat storage material 201 is accommodated in an internal space 201c formed in the ice pack body 202.

[0054] As shown in FIGS. 9 and 10, the cooling device main body 202 comprises a storage member 211, an injection port 212, and a sealing member 213.

[0055] The housing member 211 has a hollow structure, whereby an internal space 201c in which the latent heat storage material 201 is housed is formed in the housing member 211.

[0056] The containing member 211 is preferably made of a material having high rigidity. This makes it possible to suppress the change in shape of the containing member 211 when the latent heat storage material 201 changes from a solid to a liquid. This allows the human body cooling device 2 to have a feature in which the change in shape is small when the latent heat storage material 201 changes from a solid to a liquid.

[0057] The material constituting the storage member 211 includes, for example, at least one selected from the group consisting of a resin material, a metal material, and an inorganic material. 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 storage member 211 is preferably a resin material. This can improve the ease of manufacturing and durability of the storage member 211.

[0058] The inlet 212 is coupled to the top of the containing member 211 .

[0059] The sealing member 213 seals the injection port 212 .

[0060] The cooling device 2 is placed close to or in contact with the object to be insulated. This allows the object to be kept cold at a temperature near the main melting point of the latent heat storage material 201.

[0061] 2.2 Manufacturing method of cooling devices 11A to 11C are diagrams that schematically illustrate a manufacturing device 221 used to manufacture the human body cooling apparatus 2 of the second embodiment.

[0062] 11A to 11C, when the human body cooling device 2 is manufactured, the latent heat storage material 201, which is a liquid, is injected into the housing member 211 via the injection port 212 by a cylinder pump 231. The latent heat storage material 201 may also be injected into the housing member 211 by other methods. For example, the latent heat storage material 201 may be injected into the housing member 211 by a mono pump.

[0063] 11A, when the latent heat storage material 201 is injected into the accommodation member 211, the tip of a filling hose 241 of the cylinder pump 231 is connected to the injection port 212. In addition, the tip of a suction hose 242 of the cylinder pump 231 is inserted into the latent heat storage material 201.

[0064] 11B, 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 sucked into the inside of the cylinder 244 of the cylinder pump 231 via the suction hose 242.

[0065] 11C, the piston 243 of the cylinder pump 231 is raised. This causes the latent heat storage material 201 to be discharged from the inside of the cylinder 244 of the cylinder pump 231. The discharged latent heat storage material 201 is injected into the accommodating member 211 via the filling hose 241. The amount of the latent heat storage material 201 to be injected is not limited, but is preferably 70% or more and 90% or less of the internal volume of the accommodating member 211.

[0066] Subsequently, the injection port 212 is sealed with the sealing member 213. The sealing of the injection port 212 with the sealing member 213 is performed, for example, by welding the sealing member 213 to the injection port 212. As a result, the injection port 212 is hermetically sealed with the sealing member 213. This makes it possible to prevent the latent heat storage material 201 from leaking from the accommodating member 211. The welding of the sealing member 213 to the injection port 212 is performed by ultrasonic welding, thermal welding, or the like.

[0067] The sealing of injection port 212 with sealing member 213 may be performed by using sealing member 213 as a screw plug and screwing it onto injection port 212. This allows sealing member 213 to be a plug that can be freely opened and closed by hand.

[0068] Next, the human body cooling device 2 is left standing in an environment having a temperature equal to or lower than the solidification temperature of the latent heat storage material 201. As a result, the latent heat storage material 201 solidifies.

[0069] When the ice pack 2 is housed in a logistics packaging container, the latent heat storage material 201 is solidified before the ice pack 2 is housed in the logistics packaging container. However, if the temperature inside the logistics packaging container can be made lower than 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 housed 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.

[0070] 3 Third embodiment 3.1 Logistics packaging containers (food cold storage equipment) FIG. 12 is a cross-sectional view that schematically illustrates a logistics packaging container 3 according to the third embodiment.

[0071] The logistics packaging container 3 keeps the refrigerated object X cold. The logistics packaging container 3 is used to transport the refrigerated object X in a cold state. The refrigerated object X is, for example, a frozen food that is kept cold at a temperature of -18°C or lower. When the refrigerated object X is a frozen food, the logistics packaging container 3 also serves as a food cooling device that keeps the frozen food cold.

[0072] As shown in FIG. 12, the logistics packaging container 3 includes the cooling device 2 of the second embodiment and a logistics packaging container main body 301.

[0073] The logistics packaging container body 301 accommodates the cooling device 2 and the object X to be insulated.

[0074] The cooling device 2 sandwiches the object X to be insulated from above and below. As a result, at least a portion of the cooling device 2 comes into contact with the object X. As a result, heat is conducted from the object X to the cooling device 2 via the contact surface 2a between the object X and the cooling device 2. This allows the object X to be effectively insulated. In addition, it is possible to prevent heat flowing from the outside of the logistics packaging container 3 into the inside of the logistics packaging container 3 from affecting the object X. As a result, the cooling device 2 can insulate the object X at a temperature near the main melting point of the latent heat storage material 201. The logistics packaging container 3 is suitable for use in the storage and transportation of frozen foods that are kept cold at temperatures of -18°C or below.

[0075] The logistics packaging container 3 may include a heat insulating member disposed above the cooling device 2. This can improve the cooling performance of the logistics packaging container 3.

[0076] The shape, number, and posture of the cooling devices 2 during use may be changed depending on the shape, properties, etc. of the object X to be cooled.

[0077] 4 Fourth embodiment 4.1 Cooling devices Fig. 13 is a perspective view that schematically illustrates a human body cooling apparatus 4 of the fourth embodiment. Fig. 14 is a cross-sectional view that schematically illustrates a human body cooling apparatus 4 of the fourth embodiment. Fig. 14 illustrates a cross section at the position of cutting line XI-XI drawn in Fig. 13.

[0078] The cooling device 4 is a so-called film pack type cooling device.

[0079] As shown in FIGS. 13 and 14, the human body cooling tool 4 includes a latent heat storage material 401 and a human body cooling tool 402.

[0080] The latent heat storage material 401 is the latent heat storage material of the first embodiment.

[0081] As shown in FIGS. 13 and 14, the cooling device main body 402 comprises a plurality of storage sections 411 and a plurality of joint sections 412.

[0082] Each of the plurality of containing sections 411 liquid-tightly contains the phase change material 401. The phase change material 401 is contained in an internal space 411c formed in each of the plurality of containing sections 411.

[0083] Each of the plurality of storage sections 411 has a rectangular planar shape and an elliptical cross-sectional shape. Each of the plurality of storage sections 411 may have a planar shape other than the rectangular planar shape, and may have a cross-sectional shape other than the elliptical cross-sectional shape.

[0084] The ice pack main body 402 is provided with three storage sections 411. The number of storage sections 411 provided in the ice pack main body 402 may be increased or decreased. The number of storage sections 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.

[0085] The latent heat storage material 401 may be one type of latent heat storage material, or may be two or more types of latent heat storage materials having different melting points. When two or more types of latent heat storage materials having different melting points are stored in multiple storage sections 411, multiple objects to be kept cold at different temperatures can be kept cold simultaneously.

[0086] 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, it is possible to give the ice pack 4 a shape that conforms to the object to be kept cold, even when the latent heat storage material 401 is in a solid state. 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 kept cold effectively, even if the object has a complex shape.

[0087] 14, the cooling device main body 402 includes two film members 421. The two film members 421 are joined to each other at a plurality of joints 431 to form a plurality of joint sections 412, and are not joined to each other at the remaining sections to form a plurality of storage sections 411.

[0088] 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 each other. The film member 421 is also made of a flexible material that can impart joint functions to the multiple joint portions 412.

[0089] 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 one type of material or a combination of two or more types of materials.

[0090] The film member 421 may be a single-layer film or a multi-layer film. The film member 421 is preferably 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 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 the formation of multiple joint portions 412.

[0091] The film member 421 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 film member 421.

[0092] The cooling device 4 may be provided with a temperature indicator sticker that indicates the temperature and is attached to the film member 421. This makes it possible to recognize the temperature of the cooling device 4.

[0093] 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 is provided with a film that wraps the film member 421. This can improve the physical strength, feel, and heat insulation of the cooling device 4.

[0094] The ice pack 4 may be attached to a fixing jig for fixing the ice pack 4 to the object to be cooled, and fixed to the object to be cooled. The fixing jig is, for example, a supporter, towel, bandage, or the like.

[0095] 4.2 Manufacturing method of cooling devices FIG. 15 is a diagram schematically illustrating a manufacturing device 441 used to manufacture the human body cooling device 4 of the fourth embodiment.

[0096] The manufacturing device 441 is a so-called vertical pillow type packaging machine that is also used for packaging food.

[0097] As shown in FIG. 15, when the cooling device 4 is manufactured, the latent heat storage material 401 stored in the thermostatic bath 451 is transported to the stirring bath 452.

[0098] Subsequently, the latent heat storage material 401 transported to the stirring tank 452 is stirred by the stirrer 453 .

[0099] Next, two films 454 are unwound from a film roll (not shown).

[0100] Subsequently, both ends of the two films 454 extending in the longitudinal direction are joined together by a former section 455 .

[0101] Next, both ends of the two joined films 454 are heat-pressed together by vertical seal portion 456. As a result, the two films 454 form a cylindrical object.

[0102] Next, the two films 454 constituting the cylindrical object are heat-pressed together by horizontal sealing section 457 along a pressure-bonding line extending in the minor axis direction of the two films 454 .

[0103] Next, the pump 459 is operated. As a result, the stirred latent heat storage material 401 is poured into the inside of the cylindrical object formed by the two films 454.

[0104] Next, the two films 454 constituting the cylindrical object are again thermocompressed by the horizontal sealing section 457 along a compression line extending in the minor axis direction of the two films 454. This forms the storage section 411 and the joint section 412. The latent heat storage material 401 is stored in the formed storage section 411.

[0105] 5 Fifth embodiment 5.1 Logistics packaging containers (food cold storage equipment) FIG. 16 is a cross-sectional view that schematically illustrates a logistics packaging container 5 according to the fifth embodiment.

[0106] The logistics packaging container 5 keeps the refrigerated object X cold. The logistics packaging container 5 is used to transport the refrigerated object X in a cold state. The refrigerated object X is, for example, a frozen food that is kept cold at a temperature of -18°C or lower. When the refrigerated object X is a frozen food, the logistics packaging container 5 also serves as a food cooling device that keeps the frozen food cold.

[0107] As shown in FIG. 16, the logistics packaging container 5 includes the cooling device 4 of the fourth embodiment and a logistics packaging container main body 501.

[0108] The physical distribution packaging container body 501 accommodates the cooling device 4 and the object X to be insulated.

[0109] The cooling device 4 covers the object X to be insulated from above. As a result, at least a portion of the cooling device 4 comes into contact with the object X. As a result, heat is 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 insulated. In addition, it is possible to prevent heat flowing from the outside of the logistics packaging container 5 into the inside of the logistics packaging container 5 from affecting the object X. Therefore, the cooling device 4 can insulate the object X at a temperature near the main melting point of the latent heat storage material 401. Therefore, the cooling device 4 is suitable for use in insulating and transporting frozen foods that are kept cold at temperatures of -18°C or lower.

[0110] The shape, number, and posture of the cooling devices 4 during use may be changed depending on the shape, properties, etc. of the object X to be cooled.

[0111] 5.2 Variations FIG. 17 is a cross-sectional view that schematically illustrates a logistics packaging container 5A according to a modification of the fifth embodiment.

[0112] 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 disposed between the object to be refrigerated X and the bottom surface 510a of the logistics packaging container main body 501. This makes it possible to prevent heat from flowing into the object to be refrigerated X via the bottom surface 510a of the logistics packaging container main body 501.

[0113] As described above, the cooling device 2 has a feature that the shape change is small when the latent heat storage material 201 changes from a solid to a liquid. Therefore, in the logistics packaging container 5A, the object to be refrigerated X can be stably placed on the cooling device 2.

[0114] 6 Sixth embodiment 6.1 Cooling devices Fig. 18 is a plan view that schematically illustrates a human body cooling apparatus 6 of the sixth embodiment. Fig. 19 is a cross-sectional view that schematically illustrates a human body cooling apparatus 6 of the sixth embodiment.

[0115] The cooling device 6 is a so-called blister pack type cooling device.

[0116] As shown in FIGS. 18 and 19, the human body cooling tool 6 includes a latent heat storage material 601 and a human body cooling tool 602.

[0117] The latent heat storage material 601 is the latent heat storage material of the first embodiment.

[0118] As shown in FIGS. 18 and 19, the cooling device main body 602 comprises a plurality of storage sections 611 and a plurality of joint sections 612.

[0119] Each of the plurality of containing sections 611 liquid-tightly contains the phase change material 601. The phase change material 601 is contained in an internal space 611c formed in each of the plurality of containing sections 611.

[0120] Each of the plurality of storage sections 611 has a rectangular planar shape and a trapezoidal cross-sectional shape. Each of the plurality of storage sections 611 may have a planar shape other than a rectangular planar shape, or a cross-sectional shape other than a trapezoidal cross-sectional shape.

[0121] The ice pack main body 602 is provided with six storage sections 611. The number of storage sections 611 provided in the ice pack main body 602 may be increased or decreased. The number of storage sections 611 provided in the ice pack main body 602 is changed according to the size of the object to be kept cold. This allows the size of the ice pack 602 to be changed according to the size of the object to be kept cold.

[0122] The latent heat storage material 601 may be one type of latent heat storage material, or may be two or more types of latent heat storage materials having different melting points. When two or more types of latent heat storage materials having different melting points are stored in multiple storage sections 611, multiple objects to be kept cold at different temperatures can be kept cold simultaneously.

[0123] When the object to be kept refrigerated has a can-like shape, contact surface 611a of storage section 611 may be a concave curved surface that fits the convex curved surface of the object to be kept refrigerated. When the object to be kept refrigerated has a tapered shape, the thickness of storage section 611 may be varied along the longitudinal direction of storage section 611.

[0124] 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, it is possible to give the cooling device 6 a shape that conforms to the object to be kept cold, even when the latent heat storage material 601 is in a solid state. 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.

[0125] 19, 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 a plurality of joints 631 to form a plurality of joint sections 612, and are not joined to each other at the remaining sections to form a plurality of storage sections 611.

[0126] 18 and 19, the accommodating member 621 has a plurality of recesses 641. The sealing member 622 has a flat plate shape. The recesses 641, together with the sealing member 622, form a plurality of accommodating sections 611.

[0127] The accommodating member 621 is made of a material having a hardness that allows it to maintain the shape of the recess 641. The accommodating member 621 and the sealing member 622 are made of a material that can suppress leakage and volatilization of the latent heat storage material 601. Furthermore, the accommodating member 621 and the sealing member 622 are made of a material that can be bonded to each other. Furthermore, the accommodating member 621 and the sealing member 622 are made of a material that is flexible enough to impart joint functions to the multiple joint portions 612.

[0128] 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 one type of material or a combination of two or more types of materials.

[0129] The housing member 621 desirably has a thickness of 100 μm or more and 1000 μm or less, which makes it possible to impart flexibility to the housing member 621. This makes it possible to impart joint functions to the multiple joint portions 612.

[0130] 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 one type of material or a combination of two or more types of materials.

[0131] The sealing member 622 desirably has a thickness of 50 μm or more and 100 μm or less, which makes it possible to impart flexibility to the sealing member 622. This makes it possible to impart joint functions to the multiple joint portions 612.

[0132] 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 including 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 included in the housing member 621 and the sealing member 622 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 the formation of multiple joint portions 612.

[0133] At least one of the housing member 621 and the sealing member 622 may include a base material and a thin film disposed on the base material. 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.

[0134] The cooling equipment 6 may be provided with a temperature-indicating sticker that indicates the temperature and is attached to at least one of the containing member 621 and the sealing member 622. This makes it possible to recognize the temperature of the cooling equipment 6.

[0135] The accommodating member 621 and the sealing member 622 may have fixing parts for maintaining the cylindrical shape of the cooling device 6. This allows the cooling device 6 to surround the object to be kept cold when the cooling device 6 is brought close to or in contact with the object to be kept cold. The fixing parts include, for example, hook-and-loop fasteners provided on the surface 621a of the accommodating member 621 and the surface 622a of the sealing member 622.

[0136] 6.2 Variations Fig. 20 is a perspective view that schematically illustrates a human body cooling apparatus 6A that is a modified example of the sixth embodiment.Fig. 21 is a cross-sectional view that schematically illustrates a human body cooling apparatus 6A that is a modified example of the sixth embodiment.

[0137] The human cooling device 6A differs from the human cooling device 6 in that it includes a human cooling device support 651.

[0138] 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 accommodating member 621 is arranged radially inside and the sealing member 622 is arranged radially outside. By including the cooling device support 651, the cooling device 6A has a cylindrical shape and can stand on its own.

[0139] The cooling device support 651 is preferably made of a material that has heat insulating properties and can prevent heat exchange between the outside of the cooling device support 651 and the inside of the cooling device support 651.

[0140] The material constituting the cooling tool support 651 includes, for example, at least one selected from the group consisting of foamed polyethylene, foamed urethane, and chloroprene rubber (foamed rubber).

[0141] 21, 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 main melting point of the latent heat storage material 601.

[0142] The cooling device support 651 is preferably made of an elastic material. This allows the cooling device support 651 to be elastically deformed 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.

[0143] 6.3 Manufacturing method of cooling device 22A to 22D are cross-sectional views that schematically illustrate intermediate products obtained when manufacturing the human body cooling apparatus 6 of the sixth embodiment.

[0144] When the cooling device 6 is manufactured, as shown in FIG. 22A, a hard film 671, which is a precursor of the containing member 621, is placed on a mold 661 in which a groove portion 661g having a trapezoidal cross section is formed.

[0145] 22B, the shape of the grooves 661g formed in the mold 661 is transferred to the hard film 671 by vacuum molding, press working, etc. In this way, the containing member 621 is formed.

[0146] Next, as shown in FIG. 22C, the liquid latent heat storage material 601 is poured into the recess 641 of the containing member 621 by a pump or the like.

[0147] 22D, the sealing member 622 is placed on the accommodating member 621. The contact surfaces of the accommodating member 621 and the sealing member 622 are then thermocompressed together to form the accommodating portion 611 and the joint portion 612.

[0148] 7 Seventh embodiment 7.1 Logistics packaging containers (food cold storage equipment) FIG. 23 is a cross-sectional view that schematically illustrates a logistics packaging container 7 according to the seventh embodiment.

[0149] The logistics packaging container 7 keeps the refrigerated object X cold. The logistics packaging container 7 is used to transport the refrigerated object X in a cold state. The refrigerated object X is, for example, a frozen food that is kept cold at a temperature of -18°C or lower. When the refrigerated object X is a frozen food, the logistics packaging container 7 also serves as a food cooling device that keeps the frozen food cold.

[0150] As shown in FIG. 23, the logistics packaging container 7 comprises the cooling device 6 of the sixth embodiment and a logistics packaging container main body 701.

[0151] The physical distribution packaging container body 701 accommodates the cooling device 6 and the object X to be insulated.

[0152] The cooling device 6 covers the object X to be insulated from above. As a result, at least a portion of the cooling device 6 comes into contact with the object X. As a result, heat is 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 insulated. In addition, it is possible to prevent heat flowing from the outside of the logistics packaging container 7 into the inside of the logistics packaging container 7 from affecting the object X. Therefore, the cooling device 6 can insulate the object X at a temperature near the main melting point of the phase change material 601. Therefore, the cooling device 6 is suitable for use in insulating and transporting frozen foods that must be maintained at a temperature of -18°C or below.

[0153] The logistics packaging container 7 may include a heat insulating member disposed above the cooling device 6. This can improve the cooling performance of the logistics packaging container 7.

[0154] In the logistics packaging container 7, the surface 621a of the containing member 621 and the bottom surface 701a of the logistics packaging container main body 701 may be fixed to each other by a hook-and-loop fastener or the like.

[0155] 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 has the same effect, or a configuration that can achieve the same purpose.

Claims

1. a composition comprising 6 to 29 parts by weight of ammonium chloride, 6 to 29 parts by weight of urea, and 42 to 88 parts by weight of water, wherein the total amount of the ammonium chloride, urea, and water is 100 parts by weight, and the composition has a main melting point in the range of −18° C. to −21° C.; The latent heat storage material further comprises a supercooling inhibitor, wherein the supercooling inhibitor is ammonium aluminum sulfate dodecahydrate.

2. 14 to 16 parts by weight of ammonium chloride, 15 to 18 parts by weight of urea, and 66 to 71 parts by weight of water. The latent heat storage material according to claim 1 .

3. The latent heat storage material according to claim 1 or 2, A cooling device body that accommodates the latent heat storage material in a liquid-tight manner; A cooling device equipped with:

4. the cooling device main body comprises a plurality of storage sections and a joint section that connects two adjacent storage sections included in the plurality of storage sections to each other, Each of the plurality of storage sections stores the latent heat storage material in a liquid-tight manner. The cooling device according to claim 3.

5. A logistics packaging container comprising the cooling device according to claim 3 or 4.

6. A food cooling device comprising the cooling device according to claim 3 or 4.

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