Latent heat storage material, and cold storage device, appliance, and cold storage method using the same

Abstract

To provide a latent heat storage material which has a melting point at 2-8°C and of which the melting point can be adjusted in a temperature range of 2-8°C, a cold insulation tool using the latent heat storage material, a tool, and a cold insulation method.SOLUTION: A latent heat storage material contains tetrabutylammonium bromide, urea and water, and contains 26-55 pts.wt. tetrabutylammonium bromide and 3-23 pts.wt. urea based on 100 pts.wt. of a total amount of tetrabutylammonium bromide, urea and water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a latent heat storage material, a cold storage device, an appliance, and a cold storage method using the same.

Background Art

[0002] For latent heat storage materials, cold storage at an appropriate temperature according to the type of object to be cooled is required. For example, in order to transport pharmaceuticals such as blood, specimens, and vaccines, it is necessary to control the temperature to 2 to 8°C. More precisely, it is preferable to control the temperature of specimens and vaccines at 2 to 8°C and that of blood at 2 to 6°C.

[0003] Conventionally, as a latent heat storage material for cooling an object at a temperature exceeding 0°C, studies have been made on using a latent heat storage material mainly composed of a clathrate hydrate. For example, it is well known that a quaternary ammonium salt forms a clathrate hydrate under normal pressure. When a clathrate hydrate is formed, heat is generated, and when it dissociates, heat is absorbed. Utilizing this, it has been applied as a latent heat storage material (Patent Document 1).

[0004] Patent Document 1 discloses a heat storage agent using a (quasi) clathrate hydrate formed from an aqueous solution containing tetrabutylammonium bromide, which is a kind of quaternary ammonium salt, as a solute. Inorganic hydrates such as sodium sulfate decahydrate and sodium acetate trihydrate, which are materials used as the main component of a latent heat storage material having a melting point of 0°C or higher with materials other than the clathrate hydrate, are likely to cause a phase separation phenomenon in which an anhydride that does not act as a latent heat storage material precipitates when solidification and melting are repeated for use in cooling an object to be cooled, whereas the clathrate hydrate of tetrabutylammonium bromide is known to be less likely to cause phase separation. In addition, the clathrate hydrate of a quaternary ammonium salt is non-flammable and has a relatively high latent heat, so it is useful as a latent heat storage material.

[0005] On the other hand, when using an inclusion hydrate as a latent heat storage material, it is required to control the melting point within an appropriate temperature range for cooling the object. Generally, however, the melting point of an inclusion hydrate is uniquely determined by the type of molecules forming the inclusion hydrate. Non-Patent Document 1 shows that inclusion hydrates having different melting points can be obtained by changing the chemical structure of a quaternary ammonium salt.

[0006] In Patent Document 2, a method of adjusting the melting point by mixing a plurality of inclusion hydrates of a specific quaternary ammonium salt and forming their eutectic is adopted.

[0007] Patent Document 3 discloses a method of adjusting the melting point by adding a specific inorganic salt to an inclusion hydrate of a quaternary ammonium salt and using a crystal compound composed of a ternary system of quaternary ammonium salt - inorganic salt - water.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0009]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] In the method described in Non-Patent Document 1, although a certain correlation between the melting point and the type of inclusion hydrate can be seen by changing the chemical structure, this correlation is discontinuous and it is difficult to find a quaternary ammonium salt showing an arbitrary melting point.

[0011] In the method described in Patent Document 2, the combination of inclusion hydrates forming a eutectic is limited, and the melting point can be controlled only within the range of the melting points of the respective inclusion hydrates to be mixed. In particular, since an inclusion hydrate having a melting point near 0°C is extremely rare, it is extremely difficult to control the melting point to 2 to 8°C.

[0012] In the method described in Patent Document 3, the melting point of a crystal compound composed of a ternary system of a quaternary ammonium salt - inorganic salt - water is determined by the combination of the quaternary ammonium salt and the inorganic salt. Therefore, in order to adjust the melting point to a more precise transport temperature in the temperature range of 2 to 8°C, it is necessary to search for a new combination of a quaternary ammonium salt and an inorganic salt, and it is extremely difficult to find a combination having a melting point at an appropriate temperature.

[0013] The present invention has been made in view of the above circumstances, and an object thereof is to provide a latent heat storage material having a melting point of 2 to 8°C and capable of adjusting the melting point in the temperature range of 2 to 8°C, a cold storage device, an appliance, and a cold storage method using this latent heat storage material.

Means for Solving the Problems

[0014] As a result of intensive studies to solve the above problems, the present inventors have clarified that by adding urea to an inclusion hydrate of tetrabutylammonium bromide, a solid phase composed of a ternary system of tetrabutylammonium bromide - urea - water can be obtained during solidification, and the solid phase has a melting point in the range of 2 to 8°C, and since the melting point of the solid phase can be adjusted by changing the concentration of tetrabutylammonium bromide, this was applied to a latent heat storage material.

[0015] For example, in pharmaceutical transportation, there are more stringent transportation temperatures for each item to be transported. For specimens and vaccines, transportation at 2 - 8°C is suitable, and for blood, transportation at 2 - 6°C is preferred. If the melting point of the latent heat storage material used for cold insulation can be adjusted within the temperature range of 2 - 8°C, strict temperature control can be achieved for each type of object to be kept cold, and transportation that minimizes the deterioration of each pharmaceutical can be realized.

[0016] A latent heat storage material according to one embodiment of the present disclosure is a latent heat storage material containing tetrabutylammonium bromide, urea, and water, and is characterized by containing 26 - 55 parts by weight of tetrabutylammonium bromide and 3 - 23 parts by weight of urea with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water. Preferably, the latent heat storage material contains 26 - 40 parts by weight of tetrabutylammonium bromide with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water. Also preferably, the latent heat storage material contains 41 - 55 parts by weight of tetrabutylammonium bromide with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water. A cold insulation device according to one embodiment of the present disclosure is a cold insulation device for keeping a cold insulation target cold, and includes the latent heat storage material and a storage part for storing the latent heat storage material in a liquid-tight manner. Preferably, the cold insulation device has a plurality of the storage parts and a joint part for connecting the plurality of storage parts to each other. An implement according to one embodiment of the present disclosure includes the cold insulation device. This implement may be a logistics packaging container, a human body cooling device, a beverage cold insulation device, or a food cold insulation device. A cold insulation method according to one embodiment of the present disclosure is to bring the cold insulation device into contact with at least a part of the cold insulation target and cover the cold insulation target. Further, preferably, the upper and lower surfaces and the side surfaces of the cold insulation target are covered using the cold insulation device.

Advantages of the Invention

[0017] According to the present invention, it is possible to provide a latent heat storage material having a melting point in the temperature range of 2 to 8°C and capable of adjusting the melting point in the temperature range of 2 to 8°C, a cold storage device using this latent heat storage material, a logistics packaging container using this cold storage device, a human body cooling device, a cold storage device for beverages, a food cold storage device, and a method for transporting a cold storage object using a logistics packaging container. For example, in pharmaceutical transportation, specimens and vaccines that can be temperature-controlled at 2 to 8°C are temperature-controlled using a latent heat storage material with a melting point adjusted to 5°C so as not to deviate from the temperature range of 2 to 8°C, and blood transportation that requires strict temperature control at 2 to 6°C is temperature-controlled using a latent heat storage material with a melting point adjusted to 3°C, enabling such control.

Brief Description of the Drawings

[0018]

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Embodiments for Carrying Out the Invention

[0019] ≪First Embodiment≫ <Latent heat storage material> This embodiment is a latent heat storage material containing tetrabutylammonium bromide (hereinafter referred to as "TBAB"), urea, and water. The latent heat storage material of this embodiment contains 26 to 55 parts by weight of TBAB and 3 to 23 parts by weight of urea with respect to a total of 100 parts by weight of TBAB, urea, and water.

[0020] The latent heat storage material of this embodiment produces a solid phase composed of a ternary system of TBAB-urea-water by solidification.

[0021] The latent heat storage material of this embodiment exhibits a melting point different from that of the solid phase formed by the solidification of the binary system of TBAB-water and the binary system of urea-water. Thereby, a latent heat storage material having a melting point in the temperature range of 2 to 8°C can be provided.

[0022] In this specification, "clathrate hydrate" refers to a compound in which guest molecules are encapsulated in a cage-like inclusion lattice composed of water molecules (host molecules) and crystallize.

[0023] In this specification, "semi-clathrate hydrate" refers to a compound in which a relatively large ionic guest molecule typified by tetrabutylammonium salt is encapsulated in a cage-like inclusion lattice of water molecules (host molecules), and the hydrogen bonds in the inclusion lattice crystallize in a state where they are partially broken. In the following description, when referring to "clathrate hydrate", "semi-clathrate hydrate" is also included.

[0024] It is known that the clathrate hydrate of quaternary ammonium salt is formed under normal pressure and generates heat during formation. On the other hand, it is known to absorb heat when the clathrate hydrate dissociates. The latent heat storage material of this embodiment can utilize a large amount of latent heat by using TBAB that forms such a clathrate hydrate. In particular, among quaternary ammonium salts, TBAB has a low production cost and is easy to form a clathrate hydrate. For this reason, TBAB is preferably used as a raw material for the latent heat storage material.

[0025] TBAB is an ionic substance and dissociates into tetrabutylammonium ions and bromide ions when dissolved in water. Therefore, when an ionic substance is added to the TBAB-water system, unless it is an ionic substance composed of bromide ions, other tetrabutylammonium salts in which the bromide ions of TBAB are replaced by other anions may be generated, and a clear melting point may not be shown during solidification. On the other hand, since urea is a non-ionic substance, there is no risk of the bromide ions of TBAB being replaced.

[0026] The formation and dissociation of the clathrate hydrate are similar to the phase transition from a solid such as ice to a liquid such as water. For such reasons, in this specification, the dissociation of the clathrate hydrate may be referred to as "melting".

[0027] In the present embodiment, the concentrations of TBAB and urea are 26 to 55 parts by weight of TBAB and 3 to 23 parts by weight of urea with respect to a total of 100 parts by weight of TBAB, urea, and water.

[0028] When the TBAB concentration is extremely low, excess water that does not contribute to the formation of the clathrate hydrate during solidification is generated, and ice is generated during solidification. When the amount is less than 26 parts by weight of TBAB, the latent heat amount derived from ice exceeds the latent heat amount of the melting component at 2 to 8°C. Even if solidification is carried out at a temperature exceeding 0°C so that ice does not form, the latent heat amount is small for cold storage applications at 2 to 8°C. On the other hand, when the TBAB concentration is extremely high, TBAB that does not contribute to the formation of the clathrate hydrate remains during solidification. When it exceeds 55 parts by weight of TBAB, the ratio of TBAB that does not contribute to the formation of the clathrate hydrate exceeds the ratio of TBAB that contributes to the formation of the clathrate hydrate, resulting in an excessive TBAB content and a small latent heat amount. Therefore, the manufacturing cost relative to the latent heat amount obtained from the latent heat storage material becomes relatively high.

[0029] On the other hand, when the urea concentration is extremely low, a melting component exceeding the temperature range of 2 to 8°C, which is derived from the clathrate hydrate composed of the two components of TBAB-water, is generated during solidification. When the amount is less than 3 parts by weight of urea, the latent heat amount of the melting component exceeding the temperature range of 2 to 8°C exceeds the latent heat amount of the melting component at 2 to 8°C. Therefore, the latent heat amount is small for cold storage applications at 2 to 8°C. On the other hand, when the urea concentration is extremely high, urea that does not contribute to the generation of the melting component at 2 to 8°C remains during solidification. When it exceeds 23 parts by weight of urea, the ratio of urea that does not contribute to the generation of the melting component at 2 to 8°C exceeds the ratio of urea that contributes to the generation of the melting component at 2 to 8°C, resulting in an excessive urea content and a small latent heat amount. Therefore, the manufacturing cost relative to the latent heat amount obtained from the latent heat storage material becomes relatively high.

[0030] In particular, it is more preferable that the concentrations of TBAB and urea are 37 to 44 parts by weight of TBAB and 4 to 13 parts by weight of urea. In this concentration range, a high latent heat amount is retained for the melting component at 2 to 8 °C.

[0031] <Method for manufacturing latent heat storage material> The latent heat storage material of the present embodiment is obtained by mixing TBAB, urea, and water at a predetermined ratio. After adding water to the container, TBAB and urea are added and stirred well to make it uniform, thereby obtaining the latent heat storage material.

[0032] Other components that may be included in the latent heat storage material of the present embodiment include thickeners such as xanthan gum, guar gum, carboxymethyl cellulose, sodium polyacrylate, and dyes. Further, when the latent heat storage material of the present embodiment shows supercooling, that is, the solidification temperature is lower than the melting point, it may contain a supercooling inhibitor. Note that the material of the present invention is not limited to the materials exemplified above.

[0033] <Examples and Comparative Examples> The melting characteristics of the latent heat storage materials according to the examples and comparative examples were evaluated. A thermocouple was installed inside 40 g of the latent heat storage materials according to the examples and comparative examples, and the temperature during melting of each latent heat storage material was measured. Specifically, after each latent heat storage material was solidified at -20 °C, the temperature was raised at a rate of 0.25 °C / min, and the change in temperature of each latent heat storage material over time was measured with a thermocouple.

[0034] In the above melting characteristic evaluation, the start of melting was defined as the time when the temperature of the latent heat storage material deviated from the temperature rise rate and the temperature rise began to decrease, and the end of melting was defined as the time when the temperature rise began to increase again.

[0035] FIG. 1 is a graph of the melting characteristics of 40 g of a latent heat storage material (Example 1) composed of 37 parts by weight of TBAB, 13 parts by weight of urea, and 50 parts by weight of water, 40 g of a latent heat storage material (Example 2) composed of 40 parts by weight of TBAB, 13 parts by weight of urea, and 47 parts by weight of water, and 40 g of a latent heat storage material (Example 3) composed of 43 parts by weight of TBAB, 13 parts by weight of urea, and 44 parts by weight of water, which are examples of the present embodiment.

[0036] Example 1 showed a behavior where melting started around 3°C, deviated from the heating rate, and the temperature increase became small, and melting ended around 5°C and then the temperature increase became large again. Example 2 showed a behavior where melting started around 3°C and ended around 6°C. Example 3 showed a behavior where melting started around 5°C and ended around 7°C. That is, in Examples 1 to 3, melting started and heat was absorbed in the temperature range of 2 to 8°C, and melting ended at 8°C or lower. Therefore, by using the latent heat storage material of the present invention for the cold storage of pharmaceuticals, when the temperatures of the latent heat storage material and the pharmaceuticals are in the range of 2 to 8°C, the latent heat storage material absorbs heat, so that the temperature of the pharmaceuticals can be maintained within an appropriate range of 2 to 8°C.

[0037] Also, in Examples 1 to 3, the urea concentrations were equal and the TBAB concentrations were different. In Example 1 with a low TBAB concentration, melting started around 3°C and ended around 5°C, while in Example 3 with a high TBAB concentration, melting started around 5°C and ended around 7°C. That is, the melting point of the latent heat storage material of the present invention can be adjusted in the temperature range of 2 to 8°C by adjusting the TBAB concentration. Therefore, in the transportation of pharmaceuticals, the latent heat storage material of Example 1 that melts around 3°C can be used for the transportation of blood that requires temperature control at 2 to 6°C, and the latent heat storage material of Example 2 that melts around 5°C can be used for the transportation of specimens and vaccines that require temperature control at 2 to 8°C. It is possible to change the control temperature for each type of cold storage object and minimize the deterioration of each pharmaceutical.

[0038] On the other hand, Example 2 had a TBAB concentration intermediate between those of Example 1 and Example 3. In Example 2, melting started around 3°C, but the end of melting was around 6°C. That is, the TBAB concentration of 40 parts by weight in Example 2 is the upper limit of the TBAB concentration of the latent heat storage material that can be used for the transportation of blood that requires temperature control at 2 to 6°C.

[0039] The latent heat of the latent heat storage material is the value obtained by differential scanning calorimetry (DSC). Specifically, first, about 4 mg of the latent heat storage material in the liquid phase state is sealed in an aluminum pan for DSC measurement, cooled at a rate of 5 °C / min, phase-changed from the liquid phase state to the solid phase state, and then heated at a rate of 5 °C / min. At this time, an endothermic peak is obtained. The area of the endothermic peak is taken as the latent heat.

[0040] Table 1 shows the concentrations of TBAB, urea, and water in the latent heat storage materials of Examples 1 to 6 and Comparative Examples 1 to 4, and the latent heat of the melting component at 2 to 8 °C obtained by DSC, and the melting start temperature. Examples 4 to 6 and Comparative Examples 1 to 4 are examples prepared by changing the concentrations of TBAB and urea.

[0041]

Table 1

[0042] Examples 1 to 6 generally showed a high latent heat of 160 J / g or more. Therefore, in the latent heat storage material in this embodiment, with respect to a total of 100 parts by weight of TBAB, urea, and water, 37 to 44 parts by weight of TBAB and 4 to 13 parts by weight of urea are more preferable. In the above more preferable concentration range, while maintaining a high latent heat, the melting point can be adjusted by changing the TBAB concentration as described above. In particular, for the cold storage of an object that requires temperature control at 2 to 6 °C, 37 to 40 parts by weight of TBAB that can obtain a latent heat storage material that starts melting at around 3 °C is more preferable, and for the cold storage of an object that requires temperature control at 2 to 8 °C, 41 to 43 parts by weight of TBAB that can obtain a latent heat storage material that starts melting at around 5 °C is more preferable in terms of the cold storage time.

[0043] Compared with Examples 1 to 6, Comparative Examples 1 to 4 showed a low latent heat. Therefore, in Comparative Examples 1 to 4, the cold storage time is shortened.

[0044] In Comparative Example 1, the TBAB concentration was significantly low at 25 parts by weight and was below the temperature range of 2 to 8 °C in the DSC measurement.

[0045] In Comparative Example 2, the TBAB concentration was remarkably high at 56 parts by weight, and since TBAB which does not contribute to the formation of the clathrate hydrate remained during solidification, the latent heat amount was a low value of 93 J / g.

[0046] In Comparative Example 3, the urea concentration was remarkably low at 2 parts by weight and exceeded the temperature range of 2 to 8°C in the DSC measurement.

[0047] In Comparative Example 4, the urea concentration was remarkably high at 24 parts by weight, and since urea which does not contribute to the generation of the melting component at 2 to 8°C remained during solidification, the latent heat amount was a relatively low value of 89 J / g.

[0048] Also, in Comparative Example 2, when the TBAB remaining after melting in the evaluation of the melting characteristics described above was filtered and weighed, it was 30 parts by weight with respect to a total of 100 parts by weight of TBAB, urea, and water. Since 30 parts by weight, which exceeds half of 56 parts by weight of TBAB, remains, the raw materials are in excess, and the manufacturing cost with respect to the latent heat amount obtained from the latent heat storage material is relatively high.

[0049] Also, in Comparative Example 4, when the urea remaining after melting in the evaluation of the melting characteristics described above was filtered and weighed, it was 13 parts by weight with respect to a total of 100 parts by weight of TBAB, urea, and water. Since 13 parts by weight, which exceeds half of 24 parts by weight of urea, remains, the raw materials are in excess, and the manufacturing cost with respect to the latent heat amount obtained from the latent heat storage material is relatively high.

[0050] From the above, the concentrations of TBAB and urea in the latent heat storage material of the present embodiment are 26 to 55 parts by weight of TBAB and 3 to 23 parts by weight of urea with respect to a total of 100 parts by weight of TBAB, urea, and water.

[0051] In particular, for the cold storage of an object that requires temperature control at 2 to 6°C, 26 to 40 parts by weight of TBAB that can obtain a latent heat storage material that starts to melt at around 3°C is preferable, and for the cold storage of an object that requires temperature control at 2 to 8°C, 41 to 55 parts by weight of TBAB that can obtain a latent heat storage material that starts to melt at around 5°C is preferable in terms of the cold storage time.

[0052] ≪Second Embodiment≫ <Cold storage device> Hereinafter, the cold storage device using the above latent heat storage material will be described with reference to FIGS. 2 and 3. Note that the drawings used in the following description may show the characteristic parts enlarged for the purpose of emphasizing the characteristic parts, and the dimensional ratios of the respective components are not necessarily the same as the actual ones. Also, for the same purpose, parts that are not characteristic may be omitted from the illustration.

[0053] The cold storage device of this embodiment cools the object to be cooled. Examples of the object to be cooled include foods, pharmaceuticals, etc. Examples of foods include fresh produce such as vegetables and fruits, dairy products such as milk, processed foods such as ham, and beverages such as wine and champagne. Also, the cold storage device of this embodiment can also be used as a cooling device for maintaining the body temperature of the human body at a low temperature. Note that the cold storage device of this embodiment may cool a sealed space such as inside a refrigerator or a packaging container, or a space opened for purposes such as air conditioning.

[0054] In the case of fresh produce, it is said that the storage temperature is over 0°C and 15°C or lower. On the other hand, in the case of refrigerated products including dairy products such as milk and processed foods such as ham, it is said that the storage temperature is over 0°C and 10°C or lower. In the case of pharmaceuticals, it is said that the storage temperature is 2 - 8°C.

[0055] FIG. 2 is a plan view of the cold storage device 100 of the second embodiment. FIG. 3 is a cross-sectional view of FIG. 2. As shown in FIGS. 2 and 3, the cold storage device 100 includes a cold storage device main body 110 and a latent heat storage material 150. The cold storage device 100 of this embodiment is a so-called blow container type cold storage device obtained by a method of injecting the latent heat storage material using a cylinder pump described later.

[0056] The cold storage device main body 110 liquid-tightly accommodates the latent heat storage material 150 in the internal space 110c.

[0057] The cold storage device main body 110 includes a housing member 120, an injection port 170, and a sealing member 190.

[0058] The housing member 120 is a member having a hollow structure. The housing member 120 is preferably formed of a material with high rigidity. Thereby, when the latent heat storage material 150 undergoes a phase transition from a solid phase to a liquid phase, the shape of the housing member 120 is less likely to change. Such materials include resin materials such as polyethylene, polypropylene, polyester, polyurethane, polycarbonate, polyvinyl chloride, polyamide, etc., metals such as aluminum, stainless steel, copper, silver, etc., and inorganic materials such as glass, ceramics, and ceramics. From the viewpoints of ease of manufacture and durability of the housing member 120, the housing member 120 is preferably formed of a resin material.

[0059] The housing member 120 may be encapsulated by a film such as polyethylene, polypropylene, polyester, polyurethane, polycarbonate, polyvinyl chloride, polyamide, etc. For the purpose of enhancing the durability and barrier properties of the film, it is preferable that a thin film of aluminum or silicon dioxide is formed on the film. Further, it is preferable to attach a seal of a temperature indicating material indicating temperature to the housing member 120, since the temperature of the cold storage device can be determined.

[0060] The inlet 170 in FIG. 2 is provided at the upper part of the housing member 120. In the method described later, the latent heat storage material 150 is injected into the housing member 120 from the inlet 170.

[0061] The inlet 170 is sealed by a sealing member 190.

[0062] By bringing the cold storage device 100 of the present embodiment close to or in contact with an article (object to be cooled), it is possible to adjust the temperature and keep the cold of the article near the melting start temperature of the latent heat storage material of the present invention.

[0063] <Method for manufacturing a cold storage device> An example of the method for manufacturing the cold storage device 100 of the present embodiment will be described. FIG. 4 is a conceptual diagram showing the manufacturing process of the cold storage device 100 of the second embodiment.

[0064] As shown in FIG. 4, the latent heat storage material 150 is injected into the storage member 120 through the injection port 170 using the cylinder pump CP. Note that the injection method of the latent heat storage material 150 is not limited to this, and an injection method using a mono pump may also be used.

[0065] Specifically, first, the filling hose H1 of the cylinder pump CP is set to the injection port 170 of the storage member 120, and the suction hose H2 is set to the container containing the latent heat storage material 150.

[0066] Next, the piston P of the cylinder pump CP is lowered to suck up the latent heat storage material 150. Next, after filling the piston P with the latent heat storage material 150, the piston P is raised to inject the latent heat storage material 150 into the storage member 120.

[0067] The injection amount of the latent heat storage material 150 is not particularly limited, but it is preferably 70% or more and 90% or less with respect to the internal volume of the storage member 120.

[0068] Then, the injection port 170 is sealed with the sealing member 190. As a sealing method using the sealing member 190, there are a method of hermetically sealing with an existing technique such as ultrasonic welding or thermal welding, and a method of using the sealing member 190 as a screw cap and making it a cap that can be freely opened and closed by hand. When hermetically sealing by ultrasonic welding or thermal welding, etc., it is preferable because there is no risk of leakage of the latent heat storage material 150 or the like.

[0069] Finally, the cold storage device 100 is left standing in a temperature environment below the solidification temperature of the latent heat storage material 150 to solidify the latent heat storage material 150. Through such steps, the cold storage device 100 of the present embodiment is manufactured.

[0070] Note that, as described here, the latent heat storage material 150 may be solidified before placing the cold storage device 100 on the logistics packaging container described later. However, if the logistics packaging container can be placed in a temperature environment below the solidification temperature of the latent heat storage material 150 at the first stage of the logistics process, the latent heat storage material 150 in the cold storage device 100 can be used even in the liquid phase state.1

[0071] <Logistics Packaging Container> Hereinafter, a logistics packaging container using the cold storage device 100 of the second embodiment will be described with reference to FIG. 5. FIG. 5 is a cross-sectional view of a logistics packaging container 200 according to the second embodiment. The logistics packaging container 200 includes a logistics packaging container body 210 and a cold storage device 100.

[0072] The logistics packaging container body 210 is a container sized for a person to carry. The logistics packaging container body 210 is composed of a wall portion 240 and a lid portion 250.

[0073] The wall portion 240 is open for inserting and removing articles and the cold storage device 100. The wall portion 240 has a cold storage device holding portion 220 for holding the cold storage device 100. The cold storage device holding portion 220 is formed by notching the upper end of the wall portion 240 that constitutes the side surface of the logistics packaging container body 210. The cold storage device holding portions 220 are formed at the upper ends of the wall portions 240 facing each other. Note that cold storage device holding portions may be formed at the upper ends of the wall portion 240 over the entire circumference of the wall portion 240.

[0074] The cold storage device holding portion 220 is provided inside the logistics packaging container body 210. The logistics packaging container 200 is used by placing the cold storage device 100 on the cold storage device holding portion 220. Thereby, the inside of the logistics packaging container body 210 is maintained near the melting point of the latent heat storage material of the cold storage device 100. The cold storage device holding portion 220 may have a structure capable of fixing the cold storage device 100.

[0075] The wall portion 240 is preferably formed of a heat-insulating material such as expanded polystyrene, urethane foam, or vacuum insulation material. A heat-insulating layer formed of a heat-insulating material may be provided inside or outside the main body formed of a material that does not consider heat insulation.

[0076] The lid portion 250 closes the open wall portion 240. The lid portion 250 is formed of the material shown as the forming material of the wall portion 240. The lid portion 250 may be formed of the same material as the wall portion 240 or a different material.

[0077] The wall portion 240 and the lid portion 250 may be connected or separated. In order to reduce the heat transfer between the inside of the logistics packaging container 200 and the outside, it is preferable that the lid portion 250 is in close contact with the wall portion 240.

[0078] The logistics packaging container body 210 has an internal space 210c capable of accommodating articles. The internal space 210c is a region surrounded by the wall portion 240 and the lid portion 250.

[0079] When the article is accommodated in the internal space 210c of the logistics packaging container body 210, the article is held near the melting temperature of the latent heat storage material.

[0080] <Modification Example> FIG. 6 is a cross-sectional view showing a modification 200A of the logistics packaging container according to the second embodiment. As shown in FIG. 6, the logistics packaging container 200A includes two cold storage devices 100. In the logistics packaging container 200A, the two cold storage devices 100 face each other. One cold storage device 100A is held by the cold storage device holding portion 220. That is, in the logistics packaging container 200A, a part of the wall portion 240 functions as a holding member in the claims. The other cold storage device 100B is disposed on the inner bottom surface of the logistics packaging container body 210. Thereby, the heat inflow from the bottom surface 210a to the object to be cooled can be suppressed.

[0081] Further, the cold storage device 100 has little shape change when the latent heat storage material undergoes a phase transition from a solid phase to a liquid phase. Therefore, in the logistics packaging container 200A, the object to be cooled can be stably installed.

[0082] Here, there are three methods of heat transfer from one substance to another: convection, heat conduction, and heat radiation. Among them, heat conduction is considered to have the least heat loss.

[0083] In the logistics packaging container 200A, since the cold storage device 100B is arranged at such a position, the object to be cooled can be brought into contact with the cold storage device 100B inside the logistics packaging container body 210. By bringing the object to be cooled into contact with the cold storage device 100B, heat conduction occurs between the object to be cooled and the cold storage device 100B, and it is considered that the object to be cooled is cooled. In this case, it is less likely to be affected by the heat inflow from the outside into the logistics packaging container 200A.

[0084] On the other hand, when the cold storage device 100 and the object to be cooled are separated as in the logistics packaging container 200 of FIG. 5, it is considered that heat convection occurs between the cold storage device 100 and the object to be cooled, and the object to be cooled is cooled. In this case, it is easily affected by the heat inflow from the outside into the logistics packaging container 200, and it is difficult to keep the temperature near the melting temperature of the latent heat storage material.

[0085] Therefore, compared with the logistics packaging container 200, the logistics packaging container 200A is less affected by heat inflow, so it is easier to control the temperature of the object to be cooled near the melting temperature of the latent heat storage material.

[0086] When the object to be cooled is a blue fruit product, if the storage temperature is too low, so-called low-temperature damage such as black discoloration may occur. On the contrary, in the logistics packaging container 200A, since the melting start temperature of the latent heat storage material provided in the cold storage device 100B exceeds 2°C, low-temperature damage is less likely to occur.

[0087] Note that the cold storage devices 100A and 100B may have the same or different types of latent heat storage materials.

[0088] FIG. 7 is a cross-sectional view showing a modification 200B of the logistics packaging container according to the second embodiment. The difference between the logistics packaging container 200B and the logistics packaging container 200A of FIG. 6 is that it includes a cold storage device holding member 221 provided on the inner side surface of the logistics packaging container body 210. One cold storage device 100A is held by the cold storage device holding member 221. The other cold storage device 100B is arranged on the inner bottom surface of the logistics packaging container body 210.

[0089] Similar to the logistics packaging container 200A in FIG. 6, the logistics packaging container 200B is easier to control the temperature of the object to be kept cold than the logistics packaging container 200.

[0090] The logistics packaging container body according to one aspect of the present invention may be a huge container such as a container. Also, the logistics packaging container according to one aspect of the present invention may be a container equipped with a cooling device like a reefer container.

[0091] FIG. 8 is a cross-sectional view showing a modified example 200C of the logistics packaging container of the second embodiment. The difference from the logistics packaging container 200A in FIG. 6 is that the cold insulation tool holding part 220 of the logistics packaging container 200C is formed by cutting notches at the upper and lower ends of the wall part constituting the side surface of the logistics packaging container body. Thereby, even when the logistics packaging container 200C of the present embodiment is used in an inclined posture, the positions of the two cold insulation tools 100 are stable.

[0092] Similar to the logistics packaging container 200A in FIG. 6, the logistics packaging container 200C is easier to control the temperature of the object to be kept cold than the logistics packaging container 200.

[0093] The number of cold insulation tools provided in the logistics packaging container according to one aspect of the present invention is not particularly limited, and may be 3 or more.

[0094] In the logistics packaging container according to one aspect of the present invention, the cold insulation tool may be built into the logistics packaging container body. Also, the cold insulation tool itself may be the logistics packaging container.

[0095] In the logistics packaging container according to one aspect of the present invention, the lid part may have a cold insulation tool holding part.

[0096] Since the logistics packaging container 200 of the second embodiment is provided with the above-described cold insulation tool 100, it can be used for keeping cold of blue fruits and refrigerated products as well as for keeping cold of pharmaceuticals.

[0097] ≪Third Embodiment≫ <Cold Insulation Tool> Hereinafter, the cold insulation tool using the above-described latent heat storage material will be described with reference to FIGS. 9 and 10. FIG. 9 is a plan view showing the cold storage device 300 of the third embodiment. FIG. 10 is a cross-sectional view of FIG. 9. As shown in FIGS. 9 and 10, the cold storage device 300 of the present embodiment includes a latent heat storage material 150 and a cold storage device main body 310. The cold storage device 300 is a so-called blister pack type cold storage device. Therefore, components common to the second embodiment in the present embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0098] The cold storage device main body 310 has a plurality of storage portions 330 and a plurality of joint portions 340.

[0099] The storage member 320 hermetically stores the latent heat storage material 150 in the internal space 330c.

[0100] The storage member 320 is formed in a strip shape. In FIG. 10, the contour shape of the cross section of the storage portion 330 is trapezoidal, but other shapes may also be used.

[0101] In FIGS. 9 and 10, the number of the storage portions 330 is six, but it is not limited thereto. By changing the number of the storage portions 330 according to the size of the object to be cooled, the size of the cold storage device 300 can be changed.

[0102] Also, one type of latent heat storage material 150 may be stored in the plurality of storage portions 330, or two or more types of latent heat storage materials having different melting temperatures may be stored as the latent heat storage material 150. By using such a cold storage device 300, a plurality of objects to be cooled having different storage temperatures can be cooled at once.

[0103] In order to increase the contact area with the beverage can, the contact surface 330a of the storage portion 330 may be formed into a concave curved surface. Also, in order to fit the cold storage device 300 to a wine bottle or the like, the thickness t of the storage portion 330 may be changed in the longitudinal direction of the storage portion 330.

[0104] The joint part 340 connects the two accommodating parts 330 to each other and has a joint function. By having a plurality of joint parts 340, the cold storage device 300 can be brought into contact with the object to be cooled in a posture along the shape of the object to be cooled even when the latent heat storage material 150 is in a solid state. Therefore, even if the object to be cooled has a complex shape, the cold storage device 300 can effectively cool the object to be cooled.

[0105] As shown in FIG. 10, the cold storage device main body 310 is composed of an accommodating member 320 and a sealing member 390. The accommodating member 320 and the sealing member 390 are joined at a plurality of joining parts 341. The region that overlaps with the joining part 341 of the accommodating member 320 and the sealing member 390 in plan view functions as the joint part 340. The regions other than the regions that overlap with the plurality of joining parts 341 of the accommodating member 320 and the sealing member 390 in plan view function as the accommodating parts 330.

[0106] The accommodating member 320 has a plurality of recesses 321. The plurality of recesses 321 and the sealing member 390 constitute a plurality of accommodating parts 330. The accommodating member 320 is preferably formed of a material having a hardness capable of maintaining the shape of the recess 321.

[0107] The sealing member 390 is formed in a planar shape.

[0108] The accommodating member 320 and the sealing member 390 are preferably formed of a material capable of suppressing leakage and volatilization of the latent heat storage material 150. Further, the accommodating member 320 and the sealing member 390 are preferably formed of a material having flexibility to impart a joint function to the joint part 340. Further, the accommodating member 320 and the sealing member 390 are preferably formed of materials that can be joined to each other in the manufacturing method described later.

[0109] As the forming material of the accommodating member 320, for example, polyethylene, polypropylene, polyamide, polyester, polycarbonate, or polyvinyl chloride is preferable. The thickness of the accommodating member 320 is preferably, for example, 100 μm or more and 1000 μm or less. When the thickness of the accommodating member 320 is within the above range, the accommodating member 320 has flexibility. As a result, a joint function can be imparted to the joint portion 340.

[0110] The forming material of the sealing member 390 is preferably, for example, polyethylene, polypropylene, polyamide, or polyester. The thickness of the sealing member 390 is preferably 50 μm or more and 100 μm or less. When the thickness of the sealing member 390 is within the above range, the sealing member 390 has flexibility. As a result, a joint function can be imparted to the joint portion 340.

[0111] The forming materials of the accommodating member 320 and the sealing member 390 may be one type, or may be arbitrarily combined of two or more types. Further, the accommodating member 320 and the sealing member 390 may be composed of a single layer, or may be composed of a plurality of layers.

[0112] It is preferable that the accommodating member 320 and the sealing member 390 are composed of a multilayer film of a linear low-density polyethylene resin layer and a polyamide resin layer. In this case, two multilayer films are overlapped so that the linear low-density polyethylene resin layers face each other, and the joint portion 340 can be formed by thermocompression bonding the contact surfaces of the linear low-density polyethylene resin layers.

[0113] At least one of the accommodating member 320 and the sealing member 290 preferably contains a thin film of aluminum or silicon dioxide for the purpose of enhancing durability and barrier properties. Further, it is preferable to attach a seal of a temperature indicating material indicating temperature to at least one of the accommodating member 320 and the sealing member 390 because the temperature of the cold storage device 300 can be determined.

[0114] The housing member 320 and the sealing member 390 may have a fixing portion. Thereby, when the cold storage device 300 is arranged on the object to be cold-stored, it can be configured to surround the object to be cold-stored. As the fixing portion, for example, a surface fastener composed of the surface 320a of the housing member 320 and the surface 390a of the sealing member 390 can be used.

[0115] <Modification Example> FIG. 11 is a perspective view showing a modification 300A of the cold storage device according to the third embodiment. The difference between the cold storage device 300A and the cold storage device 300 in FIG. 9 is that the cold storage device support 350 is provided.

[0116] The cold storage device support 350 is substantially cylindrical, and one end of the cylinder is open. The cold storage device support 350 has a space for accommodating the latent heat storage material 150 and the cold storage device main body 310 inside. The cold storage device main body 310 is deformed into a substantially cylindrical shape with the housing member 320 on the inner side and the sealing member 390 on the outer side. By providing the cold storage device support 350, the cold storage device 300 can be substantially cylindrical and self-standing.

[0117] The cold storage device support 350 preferably has heat insulation properties and is formed of a material that prevents heat exchange with the outside air. Examples of such materials include foamed polyethylene, foamed urethane, and chloroprene rubber (foamed rubber).

[0118] <Cold Storage Method> FIG. 12 is a conceptual diagram showing a method of using the cold storage device 300A according to the third embodiment. As shown in FIG. 12, in the cold storage method using the cold storage device 300A of the third embodiment, an object X to be cold-stored, such as a beverage can or a beverage bottle, is placed in the substantially cylindrical space 300c of the cold storage device 300A. Thereby, the object X to be cold-stored and the cold storage device 300A are brought close to or into contact with each other. As a result, the object X to be cold-stored can be held near the melting start temperature of the latent heat storage material 150 of the cold storage device 300A. For example, it can be held near 5 to 8°C, which is the appropriate temperature for white wine, champagne, and sparkling wine.

[0119] In this case, in order to give the diameter of the object X to be cooled a certain range, it is preferable that at least a part of the cooler support 350 is formed of an elastic material. Due to the elastic force of the cooler support 350, the object X to be cooled and the cooler 300A are in contact with each other.

[0120] <Method of manufacturing a cooler> An example of the method of manufacturing the cooler 300 of the present embodiment will be described. FIG. 13 is a conceptual diagram showing the manufacturing process of the cooler 300 of the third embodiment. Note that the number of the accommodating portions 330 is different between FIG. 10 and FIG. 13.

[0121] First, a hard film 32, which is a raw material of the accommodating member 320, is placed in a mold MP having a groove portion with a trapezoidal cross-sectional contour shape, and the accommodating member 320 is molded by vacuum forming or pressing. Next, a certain amount of the latent heat storage material 150 in a liquid phase state is injected into the concave portion 321 of the accommodating member 320 using a pump or the like. Next, the sealing member 390 is disposed on the accommodating member 320, and the contact surfaces between the accommodating member 320 and the sealing member 390 are thermocompression bonded to form the accommodating portion 330 and the joint portion 340.

[0122] <Logistics packaging container> Hereinafter, a logistics packaging container using the cooler 300 of the third embodiment will be described with reference to FIG. 14. FIG. 14 is a cross-sectional view of a logistics packaging container 500 of the third embodiment. The logistics packaging container 500 includes a logistics packaging container main body 210 and a cooler 300. Therefore, components common to the second embodiment in the present embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0123] The logistics packaging container 500 covers the object X to be cooled from above using the cooler 300. Thereby, the logistics packaging container 500 can bring at least a part of the cooler 300 into contact with the object X to be cooled inside the logistics packaging container main body 210. It is considered that heat conduction occurs at the contact surface 300a between the object X to be cooled and the cooler 300, and the object X to be cooled is cooled. In this case, it is hardly affected by the heat inflow from the outside to the logistics packaging container 500. Therefore, the logistics packaging container 500 can efficiently cool the object X to be cooled.

[0124] In addition, the logistics packaging container 500 of the present embodiment can keep the object X to be cooled at a temperature near the melting temperature of the latent heat storage material of the cold insulator 300. Therefore, it is suitable for the cold insulation and transportation of pharmaceuticals that require strict temperature control, and the cold insulation and transportation of blue fruits that are prone to low-temperature damage.

[0125] In the logistics packaging container 500 of the present embodiment, the surface 320a of the housing member 320 and the bottom surface 210a of the logistics packaging container body 210 may be fixed by a hook-and-loop fastener or the like.

[0126] Note that the logistics packaging container 500 may be provided with a heat insulating member above the cold insulator 300 in order to enhance the cold insulation performance of the object X to be cooled.

[0127] Since the logistics packaging container 500 of the third embodiment includes the above-described cold insulator 300, it can be used for the cold insulation of blue fruits and refrigerated products as well as for the cold insulation of pharmaceuticals.

[0128] ≪Fourth Embodiment≫ <Cold Insulator> Hereinafter, the cold insulator using the above-described latent heat storage material will be described with reference to FIGS. 15 and 16. FIG. 15 is a perspective view showing the cold insulator 400 of the fourth embodiment. FIG. 16 is a cross-sectional view taken along line XI-XI of FIG. 15. As shown in FIGS. 15 and 16, the cold insulator 400 of the present embodiment includes a latent heat storage material 150 and a cold insulator body 410. The cold insulator 400 is a so-called film pack type cold insulator. Therefore, the same reference numerals are given to the components common to the second embodiment in the present embodiment, and detailed description thereof is omitted.

[0129] The cold insulator body 410 has a plurality of accommodating portions 430 and a plurality of joint portions 440.

[0130] The accommodating portion 430 hermetically accommodates the latent heat storage material 150 in the internal space 430c.

[0131] The accommodating portion 430 is formed in a strip shape. In FIG. 16, the contour shape of the cross-section of the accommodating portion 430 is elliptical, but other shapes may also be used.

[0132] Note that in FIG. 15, the number of accommodating portions 430 is three, but it is not limited to this. By changing the number of accommodating portions 430 according to the size of the object to be kept cold, the size of the cold insulation device 400 can be changed.

[0133] The joint portion 440 connects two accommodating portions 430 to each other and has a joint function. Since the cold insulation device 400 has a plurality of joint portions 440, even when the latent heat storage material 150 is in a solid state, it can be brought into contact with the object to be kept cold in a posture along the shape of the object to be kept cold. Therefore, even if the object to be kept cold has a complicated shape, the cold insulation device 400 can effectively keep the object to be kept cold.

[0134] As shown in FIG. 16, the cold insulation device main body 410 is composed of film members 420. The film members 420 are joined together at a plurality of joining portions 441. The region that overlaps with the joining portion 441 of the film member 420 in a plan view functions as the joint portion 440. The region other than the region that overlaps with the plurality of joining portions 441 of the film member 420 in a plan view functions as the accommodating portion 430.

[0135] The film member 420 is preferably formed of a material that can suppress the leakage and volatilization of the latent heat storage material 150. Further, the film member 420 is preferably formed of a material that can join the film members 420 together in the manufacturing method described later. Furthermore, the film member 420 is preferably formed of a material having flexibility that gives the joint portion 440 a joint function.

[0136] From such a viewpoint, the forming material of the film member 420 is preferably, for example, polyethylene, polypropylene, polyamide, or polyester. The forming material of the film member 420 may be one type, or may be arbitrarily combined of two or more types. Further, the film member 420 may be composed of a single layer or a plurality of layers.

[0137] The film member 420 is preferably composed of a multilayer film of a low-density polyethylene resin layer and a polyamide resin layer. In this case, two multilayer films are stacked so that the low-density polyethylene resin layers face each other, and the joint portion 440 can be formed by thermocompression bonding the contact surfaces of the low-density polyethylene resin layers.

[0138] For the purpose of enhancing the durability and barrier properties of the film member 420, it is preferable that the film member 420 includes a thin film of aluminum or silicon dioxide. Furthermore, it is preferable to attach a seal of a temperature indicating material indicating temperature to the film member 420, since the temperature of the cold storage device 400 can be determined.

[0139] Also, for the purpose of improving the physical strength, the feel, and the heat insulation property of the cold storage device 400, the outside of the film member 420 may be further packaged with a film, that is, a so-called pack-in-pack structure.

[0140] The cold storage device 400 may be attached to a fixing jig for fixing to the human body and used by fixing the cold storage device 400 to the human body as an application for cooling the human body. Examples of the fixing jig include a supporter, a towel, and a bandage.

[0141] The cold storage device 400 of the fourth embodiment can be used for cold storage of blue fruits and refrigerated products as well as for cold storage of pharmaceuticals, similarly to the cold storage device 100 of the second embodiment.

[0142] <Method for manufacturing a cold storage device> An example of the method for manufacturing the cold storage device 400 of the present embodiment will be described. FIG. 17 is a diagram showing a schematic configuration of an apparatus used for manufacturing the cold storage device 400 of the fourth embodiment. The manufacturing apparatus shown in FIG. 17 is a so-called vertical pillow type packaging machine used for packaging food.

[0143] First, the latent heat storage material 150 stored in the constant temperature bath T is transported to the stirring tank ST and stirred using the stirrer M. Next, a roll-shaped film (not shown) is fed out, and both ends in the major axis direction of the film 42 are joined together at the former part F of the packaging machine PM. Next, the both ends are bonded together to form a cylindrical shape by thermocompression bonding with the longitudinal seal part S1. Next, the minor axis direction of the cylindrical film 42 is thermocompression bonded by the transverse seal part S2. Next, the pump PU is operated, and after the latent heat storage material 150 is injected into the cylindrical film 42 through the nozzle N, the minor axis direction of the cylindrical film 42 is thermocompression bonded again by the transverse seal part S2 to form the joint part 440 and the accommodation part 430. Thereby, the cold storage device 400 can be manufactured.

[0144] <Logistics packaging container> Hereinafter, a logistics packaging container using the cold storage device 400 of the fourth embodiment will be described with reference to FIG. 18.

[0145] FIG. 18 is a cross-sectional view showing a logistics packaging container 600 of the fourth embodiment. As shown in FIG. 18, the logistics packaging container 600 includes a logistics packaging container body 210 and a cold storage device 400. Therefore, components common to the second embodiment in this embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0146] The logistics packaging container 600 covers the object to be cooled X from above using the cold storage device 400. Thereby, the logistics packaging container 600 can bring at least a part of the cold storage device 400 into contact with the object to be cooled X inside the logistics packaging container body 210. At this time, heat conduction occurs at the contact surface 400a between the object to be cooled X and the cold storage device 400, and it is considered that the object to be cooled X is cooled. In this case, it is less affected by the heat inflow from the outside into the logistics packaging container 600. Therefore, the logistics packaging container 600 can efficiently cool the object to be cooled X.

[0147] On the other hand, when cooling the object to be cooled with the coolant and the object to be cooled separated from each other as in the logistics packaging container 200 (see Fig. 5) of the second embodiment, the cooling temperature of the object to be cooled becomes higher than the melting start temperature of the latent heat storage material provided in the coolant due to heat exchange with the air existing in the internal space of the logistics packaging container body. Therefore, a material having a melting start temperature lower than the lower limit of the temperature range to be maintained by the object to be cooled is used for the latent heat storage material. However, if such a latent heat storage material is applied to the coolant 400, the temperature of the object to be cooled may fall below the lower limit of the temperature range to be maintained.

[0148] In contrast, the logistics packaging container 600 of the present embodiment can cool the object to be cooled X at a temperature near the melting temperature of the latent heat storage material of the coolant 400. Therefore, it is suitable for cooling and transporting pharmaceuticals that require strict temperature control, and for cooling and transporting blue fruits that are prone to low-temperature damage.

[0149] Note that the logistics packaging container 600 may be provided with a heat insulating member above the coolant 400 in order to enhance the cooling performance of the object to be cooled X.

[0150] The shape, number, posture during use, etc. of the coolant 400 may be appropriately adjusted according to the shape and properties of the object to be cooled X.

[0151] <Modification> Fig. 19 is a cross-sectional view showing a modified example 600A of the logistics packaging container according to the fourth embodiment. The difference between the logistics packaging container 600A and the logistics packaging container 600 of Fig. 18 is that it is provided with the coolant 100 of the second embodiment (see Fig. 3) together with the coolant 400. In the logistics packaging container 600A, the coolant 100 is disposed between the object to be cooled X and the inner bottom surface 210a of the logistics packaging container body 210. Thereby, heat inflow from the bottom surface 210a to the object to be cooled X can be suppressed.

[0152] Also, as described above, the coolant 100 has little shape change when the latent heat storage material undergoes a phase transition from a solid phase to a liquid phase. Therefore, in the logistics packaging container 600A, the object to be cooled X can be stably installed.

[0153] Since the logistics packaging container 600 of the fourth embodiment includes the above-described cold insulator 400, it can be used for cold storage of blue fruits and refrigerated products as well as for cold storage of pharmaceuticals.

[0154] <Cold storage method> With reference to FIGS. 20 to 24, the usage method of the logistics packaging container 600 of the fourth embodiment will be described.

[0155] FIG. 20 is a conceptual diagram showing the usage method of the logistics packaging container 600 of the fourth embodiment. Here, an axis A1 passing through the object X to be cooled is assumed. In the logistics packaging container 600, the object X to be cooled may be surrounded by the cold insulator 400 along the circumferential direction of the axis A1. Thereby, the object X to be cooled can be cooled also from the bottom side and the side surface side inside the logistics packaging container main body 210.

[0156] FIG. 21 is a conceptual diagram showing the usage method of the logistics packaging container 600 of the fourth embodiment. FIG. 21 shows the logistics packaging container 600 including the cold insulator 400 having two accommodating portions 430 and one joint portion 440. Inside the logistics packaging container main body 210, the object X to be cooled may be sandwiched between the two accommodating portions 430 from above and below. For example, when storing a specimen such as cells, it may be placed in a container having a small thickness such as a petri dish. It can be said that the logistics packaging container 600 shown in FIG. 21 is suitable for cooling an object to be cooled having such a shape.

[0157] FIG. 22 is a conceptual diagram showing the usage method of the logistics packaging container 600 when cooling a cylindrical article such as a pharmaceutical product or a beverage can such as a specimen or a vaccine as the object X to be cooled. FIG. 23 is a top view in the field of view seen from the upper surface 250a side of the lid portion 250 of FIG. 22. However, FIG. 23 is shown with the lid portion 250 omitted.

[0158] In FIG. 22, a logistics packaging container 600 equipped with four cold storage devices 400 is shown. Here, it is assumed that axes A11 to A14 penetrate four objects to be cooled X1 to X4 respectively. In the logistics packaging container 600, the four objects to be cooled X1 to X4 may be respectively surrounded by the four cold storage devices 400 along the circumferential direction of the axes A11 to A14. Thereby, the object to be cooled X can be cooled also from the side surface side inside the logistics packaging container main body 210.

[0159] FIG. 24 is a conceptual diagram showing a method of using the logistics packaging container 600 of the fourth embodiment. In FIG. 24, a logistics packaging container 600 equipped with two cold storage devices 400 is shown. Here, it is assumed that an axis A1 and an axis A2 penetrate the object to be cooled X. The axis A1 and the axis A2 intersect. In the logistics packaging container 600, the object to be cooled X may be respectively surrounded by the two cold storage devices 400 along the circumferential direction of the axes A1 and A2. Specifically, it is surrounded by one cold storage device 400A along the circumferential direction of the axis A1, and surrounded by the other cold storage device 400B along the circumferential direction of the axis A2. Thereby, the heat inflow from the air around the object to be cooled X can be suppressed. Therefore, the usage method shown in FIG. 24 has higher cold storage performance than the method of surrounding the object to be cooled X with the cold storage device 400 along only the circumferential direction of the axis A1. Also, the object to be cooled X can be held at a temperature extremely close to the melting temperature of the latent heat storage material of the cold storage device 400.

[0160] ≪Fifth Embodiment≫ <Food Cold Storage Utensil> Hereinafter, a food cold storage utensil using the above-mentioned latent heat storage material will be described with reference to FIG. 25. FIG. 25 is a conceptual diagram showing a method of using the food cold storage utensil 700 of the fifth embodiment. The food cold storage utensil 700 includes a logistics packaging container main body 210, a cold storage device 100, and an inner container 710. Therefore, components common to the second embodiment in this embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0161] The inner container 710 holds food. The food cold storage appliance 700 can prevent the fresh food such as meat and fish and the fresh agricultural products such as vegetables and fruits, which are stored inside the main body 210 of the logistics packaging container by the inner container 710, from directly contacting each other. Thereby, secondary contamination by food poisoning bacteria and the like can be suppressed. The surface 710a of the inner container 710 is preferably coated with an antibacterial agent or the like.

[0162] Since the food cold storage appliance 700 of the fifth embodiment includes the above-described cold storage appliance 100, it can be used for cold storage of fresh agricultural products and refrigerated products as well as for cold storage of pharmaceuticals.

[0163] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such examples. The various shapes, combinations, etc. of the constituent members shown in the above examples are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

[0164] For example, the logistics packaging container 200 of the second embodiment may use the cold storage appliance 300 of the third embodiment or the cold storage appliance 400 of the fourth embodiment in combination.

[0165] The food cold storage appliance 700 of the fifth embodiment may include the cold storage appliance 300 of the third embodiment or the cold storage appliance 400 of the fourth embodiment as the cold storage appliance.

[0166] The cold storage appliance 400 of the fourth embodiment may include a cold storage appliance support.

Explanation of Reference Numerals

[0167] 100, 100A, 100B, 300, 300A, 400, 400A, 400B... Cold storage appliances, 150... Latent heat storage material, 200, 200A, 200B, 200C, 500, 600, 600A... Logistics packaging containers, 330, 430... Accommodating portions, 340, 440... Joint portions, 700... Food cold storage appliance, A1, A2, A11, A12, A13, A14... Axes, X, X1, X2, X3, X4... Objects to be cooled

Claims

1. A latent heat storage material containing tetrabutylammonium bromide, urea, and water, with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water, a latent heat storage material characterized by containing 37 to 44 parts by weight of tetrabutylammonium bromide and 4 to 13 parts by weight of urea.

2. The latent heat storage material according to Claim 1, containing 37 to 40 parts by weight of tetrabutylammonium bromide with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water.

3. The latent heat storage material according to Claim 1, containing 41 to 44 parts by weight of tetrabutylammonium bromide with respect to a total of 100 parts by weight of tetrabutylammonium bromide, urea, and water.

4. A cold storage device for cold-storing an object to be cold-stored, comprising the latent heat storage material according to any one of Claims 1 to 3 and a housing portion for hermetically housing the latent heat storage material.

5. having a plurality of the housing portions, and a joint portion for connecting the plurality of housing portions. The cold storage device according to Claim 4.

6. An appliance comprising the cold storage device according to Claim 4 or 5.

7. The appliance according to Claim 6, wherein the appliance is any one of a logistics packaging container, a human body cooling device, a beverage cold storage appliance, and a food cold storage appliance.

8. A cold storage method of bringing the cold storage device according to Claim 4 or 5 into contact with at least a part of an object to be cold-stored and covering the object to be cold-stored.

9. Using the cold storage device according to Claim 4 or 5 to cover the upper and lower surfaces and the side surfaces of the object to be cold-stored The cold storage method according to Claim 8.

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