Cold storage material

Abstract

To provide a cold storage material suitable for storage and refrigeration of liquid medicines and food products.SOLUTION: A cold storage material comprises: tetrahydrofuran; water; and at least one silver oxide selected from the group consisting of silver phosphate represented by the chemical formula Ag3 PO4, silver carbonate represented by the chemical formula Ag2CO3, and silver oxide represented by the chemical formula AgO. This cold storage material has a melting point of 2 degrees Celsius or higher and 8 degrees Celsius or lower and a crystallization temperature of 0 degrees Celsius or higher and the melting point or lower.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a heat storage material. [Background technology]

[0002] Patent Document 1 discloses a cold storage material in which clathrate hydrate is formed by cooling. The cold storage material of Sample C-6 disclosed in Patent Document 1 is composed of 0.05 mmol of AgI and 19 wt % tetrahydrofuran aqueous solution. The cold storage material of Sample C-6 has a melting point of 4.6 degrees Celsius and a crystallization temperature of minus 7 degrees Celsius. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-059676 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a cold storage material suitable for preserving and refrigerating liquid medicines or foods. [Means for solving the problem]

[0005] The cold storage material according to the present disclosure is By containing tetrahydrofuran and water, it has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less, The present invention relates to a silver phosphate solution containing at least one silver compound selected from the group consisting of silver phosphate represented by the chemical formula Ag3PO4, silver carbonate represented by the chemical formula Ag2CO3, and silver oxide represented by the chemical formula AgO, and the molar ratio of the silver compound to the water is 2.64×10 -8 More than 3.70 x 10 -4 By: The regenerator material has a crystallization temperature equal to or higher than 0 degrees Celsius and equal to or lower than the melting point. Effect of the Invention

[0006] The present disclosure provides a cooling material suitable for preserving and refrigerating liquid medicines or foods. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a graph showing the characteristics of the cold storage material during cold storage. [Diagram 2] FIG. 2 is a graph showing the characteristics of the cold storage material when it is cooled. [Diagram 3] FIG. 3 shows a schematic diagram of a cooler box 100 according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] (First embodiment) Fig. 1 is a graph showing the characteristics of the regenerator material during cooling, in which the horizontal and vertical axes indicate time and temperature, respectively.

[0010] The cold storage material according to the first embodiment is cooled. See section A in FIG. 1. Unlike a typical liquid, as is well known in the technical field of cold storage materials, even if the cold storage material is cooled to reach its melting point, the cold storage material does not solidify but enters a supercooled state. See section B in FIG. 1. In the supercooled state, the cold storage material is liquid.

[0011] Then, the regenerator material starts to spontaneously crystallize. As the regenerator material crystallizes, it releases heat of crystallization that is approximately equal to the latent heat. As a result, the temperature of the regenerator material starts to rise. See section C in FIG. 1. In this specification, the temperature at which the regenerator material starts to spontaneously crystallize is referred to as the "crystallization temperature."

[0012] ΔT represents the difference between the melting point and the crystallization temperature of the cold storage material. ΔT may also be called the "degree of supercooling." When the cold storage material crystallizes in a supercooled state, the cold storage material becomes a semi-clathrate hydrate (see, for example, Patent Document 2). Here, the term "clathrate hydrate" refers to a crystal formed when water molecules form a cage-like crystal by hydrogen bonding and a substance other than water is enclosed in the cage. Also, the term "semi-clathrate hydrate" refers to a crystal formed when guest molecules participate in the hydrogen bond network of water molecules. The concentration at which water molecules and guest molecules form a hydrate with just the right amount is called the harmonic concentration. Generally, hydrates are often used near the harmonic concentration.

[0013] After the crystallization is completed and the heat of crystallization of the regenerator material is released, the temperature of the regenerator material gradually decreases to be equal to the ambient temperature. See section D in FIG. 1.

[0014] The crystallization temperature is lower than the melting point of the regenerator material, which can be measured using a differential scanning calorimeter (also called "DSC"), as is well known in the regenerator material art.

[0015] Fig. 2 is a graph showing the characteristics of the cold storage material during heating. In Fig. 2, the horizontal and vertical axes indicate time and temperature, respectively. During section E, the temperature of the cold storage material is maintained at a temperature below the crystallization temperature. For example, while the lid of the cooler box is closed, the temperature inside the cooler box is set to a temperature below the crystallization temperature so that the temperature of the cold storage material placed in the cooler box is maintained below the crystallization temperature.

[0016] Next, the cold storage material is gradually heated. See section F in Figure 2. For example, when the lid of the cooler box is opened (or the lid is opened and food is placed inside) at the end of section E (i.e., the beginning of section F), the temperature inside the cooler box gradually increases.

[0017] When the temperature of the cold storage material reaches its melting point, the temperature of the cold storage material is maintained near the melting point of the cold storage material. See section G in FIG. 2. If there is no cold storage material, the temperature inside the cooler box will rise continuously as shown in section Z in FIG. 2. On the other hand, if there is a cold storage material, the temperature inside the cooler box will be maintained near the melting point of the cold storage material for a certain period of section G. In this way, the cold storage material exerts its cold storage effect. At the end of section G, the crystals of the cold storage material melt and disappear. As a result, the cold storage material liquefies.

[0018] The temperature of the liquefied regenerator then rises to be equal to the ambient temperature. See section H in Figure 2.

[0019] The regenerator material can be cooled and reused.

[0020] In order for a cooling material to be suitably used for a cooler box capable of holding liquid medicines or food therein, the following conditions (I) and (II) must be satisfied. Condition (I) The cold storage material has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less. As an example, the cold storage material has a melting point of 3 degrees Celsius or more and 7 degrees Celsius or less. Condition (II) The regenerator material has a crystallization temperature of 0 degrees Celsius or higher and lower than the melting point.

[0021] The reason for condition (I) is that in order to preserve liquid medicines and food, the inside of the cooler box should be maintained at approximately 2 degrees Celsius or higher and 8 degrees Celsius or lower. If the temperature inside the cooler box is maintained below 0 degrees Celsius, the water contained inside the liquid medicines and food will turn to ice, causing the liquid medicines and food to deteriorate. On the other hand, if the temperature inside the cooler box is maintained at a temperature above 8 degrees Celsius, the cooler box will not function.

[0022] The reason for condition (II) is to increase the efficiency in the section where the cold storage material is cooled in order to obtain the function of the cold storage material (i.e., section B shown in FIG. 1). Hereinafter, this efficiency is called "crystallization efficiency". As the crystallization temperature decreases, the crystallization efficiency decreases. As is clear from FIG. 1 (particularly section B in FIG. 1), for example, in order to cool a cold storage material having a crystallization temperature of minus 18 degrees Celsius (hereinafter referred to as "minus 18 cold storage material") in order to obtain the function of the cold storage material, it is necessary to cool the cold storage material in a freezer maintained at a temperature lower than minus 18 degrees Celsius (for example, minus 20 degrees Celsius). On the other hand, for example, in order to cool a cold storage material having a crystallization temperature of minus 1 degree Celsius (hereinafter referred to as "minus 1 cold storage material") in order to obtain the function of the cold storage material, the cold storage material is cooled in a freezer maintained at a temperature lower than minus 1 degree Celsius. The energy required to cool the minus 1 cold storage material is smaller than the energy required to cool the minus 18 cold storage material. Therefore, the higher the crystallization temperature, the higher the crystallization efficiency.

[0023] In the art, the heat of fusion is also called the latent heat.

[0024] To prevent confusion, in this specification, "Kelvin" is used for the degree of supercooling ΔT. For example, the inventors write "the degree of supercooling ΔT is n Kelvin or less." Needless to say, n is a real number. The explanation "degree of supercooling ΔT≦5 Kelvin" means that the difference between the crystallization temperature and the melting point of the regenerator material is 5 Kelvin or less. On the other hand, in this specification, "Celsius" is used for temperature. For example, the inventors write "the crystallization temperature is 5 degrees Celsius (i.e., 5°C)."

[0025] The cold storage material according to the first embodiment is tetrahydrofuran, Water, and It contains at least one silver compound selected from the group consisting of silver phosphate represented by the chemical formula Ag3PO4, silver carbonate represented by the chemical formula Ag2CO3, and silver oxide represented by the chemical formula AgO.

[0026] As demonstrated in the examples described later, the cold storage material according to the first embodiment has a melting point of 2° C. or more and 8° C. or less. Therefore, the cold storage material according to the first embodiment is suitable for preserving liquid medicines and foods.

[0027] As demonstrated in the examples described later, the cold storage material according to the first embodiment has a crystallization temperature of 0 degrees Celsius or higher. On the other hand, as explained in the section on the prior art, the cold storage material according to sample C-6 of Patent Document 1 has a crystallization temperature of minus 7 degrees Celsius. Therefore, the cold storage material according to the first embodiment has high crystallization efficiency. In other words, the energy required in section B where the cold storage material according to the first embodiment is cooled is smaller than that of the cold storage material according to sample C-6 of Patent Document 1.

[0028] As is apparent from FIG. 1, the crystallization temperature is lower than the melting point.

[0029] The cold storage material according to the first embodiment contains at least one silver compound selected from the group consisting of silver phosphate represented by the chemical formula Ag3PO4, silver carbonate represented by the chemical formula Ag2CO3, and silver oxide represented by the chemical formula AgO. As demonstrated in the comparative example described later, when other silver compounds (e.g., silver iodide, silver bromide, or silver chloride) are used instead of these three silver compounds, the crystallization temperature is significantly lowered. Similarly, as demonstrated in the comparative example described later, when other metal salts (e.g., titanium oxide, vanadium oxide, iron oxide, nickel oxide, manganese oxide, or zinc oxide) are used instead of these three silver compounds, the crystallization temperature is also significantly lowered.

[0030] As long as the cold storage material according to the first embodiment has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less, and a crystallization temperature of 0 degrees Celsius or more and the melting point or less, the molar ratio of tetrahydrofuran to water in the cold storage material in the first embodiment is not limited. As an example, the molar ratio is 5% or more and 7% or less. It is known that when a cold storage material having a molar ratio of tetrahydrofuran to water of 1 / 17 is cooled, crystals of water and tetrahydrofuran are formed without excess or deficiency of water or tetrahydrofuran.

[0031] As demonstrated by Examples 1A to 3D, in the cold storage material of the first embodiment, the molar ratio of the silver compound to water is not limited. As an example, the molar ratio is 2.64×10 -8 More than 3.70 x 10 -4 The following is the result.

[0032] The cold storage material according to the first embodiment may contain additives other than tetrahydrofuran, water, and the silver compound, so long as it has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less, and a crystallization temperature of 0 degrees Celsius or more and less than the melting point.

[0033] Examples of additives are supercooling inhibitors, thickeners, and preservatives.

[0034] The cold storage material according to the first embodiment may not contain any additives. In other words, the cold storage material according to the first embodiment may be composed of tetrahydrofuran, water, and the silver compound.

[0035] The cold storage material according to the first embodiment can be produced by mixing tetrahydrofuran, water, and the silver compound.

[0036] Second embodiment A cooler box according to the second embodiment will be described below.

[0037] FIG. 3 shows a schematic diagram of a cooler box 100 according to a second embodiment.

[0038] Cooler box 100 comprises an insulated box 101 consisting of a bottom (not shown) and sides, and an insulated lid 102 .

[0039] The cold storage material according to the first embodiment is provided inside at least one selected from the group consisting of the inside bottom surface of the insulating box 101, the inside side surface of the insulating box 101, and the inside surface (i.e., the lower surface) of the insulating lid 102. In Fig. 3, cold storage material packs 110 containing the cold storage material according to the first embodiment are provided so as to contact each of the four inside side surfaces of the insulating box 101 having a rectangular parallelepiped shape.

[0040] The cold storage material according to the first embodiment may be provided in at least one selected from the group consisting of the inside of the bottom of the insulated box 101, the inside of the side of the insulated box 101, and the inside of the insulated lid 102. The cold storage material according to the first embodiment may be contained in the space inside the cooler box 100 (i.e., the space formed by the inside bottom surface of the insulated box 101, the inside side surface of the insulated box 101, and the inside surface of the insulated lid 102) so that the cold storage material according to the first embodiment is placed in the form of a cold storage material pack 110.

[0041] The cold storage material according to the first embodiment may be provided inside at least one selected from the group consisting of the side surface of the insulating box, the insulating lid of the insulating box, and the insulating box itself. In this case, the cold storage material according to the first embodiment may be provided in the form of a cold storage material pack 110.

[0042] It is desirable that at least one selected from the group consisting of medicines and food is placed inside the heat-insulating box 101. In FIG. 3, medicine 120 is placed inside the heat-insulating box 101. An example of the medicine is a liquid medicine. An example of the liquid medicine is a vaccine. When the vaccine is carried, it is required to store the vaccine at a temperature of 2 degrees Celsius or more and 8 degrees Celsius or less in order to maintain its quality. The cooler box according to the second embodiment is suitable for carrying vaccines because the cold storage material according to the first embodiment has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less.

[0043] (Example) The invention will now be described in more detail with reference to the following examples.

[0044] In this embodiment, silver phosphate is represented by the chemical formula Ag3PO4. Silver phosphate was purchased from Mitsuwa Chemical Co., Ltd. In this embodiment, silver carbonate is represented by the chemical formula Ag2CO3. Silver carbonate was purchased from Fujifilm Wako Pure Chemical Co., Ltd. In this embodiment, silver oxide is represented by the chemical formula AgO. In other words, in this specification, silver oxide is silver oxide (II) rather than silver oxide (I) represented by the chemical formula Ag2O. Silver oxide was purchased from Fujifilm Wako Pure Chemical Co., Ltd. In this embodiment, tetrahydrofuran is abbreviated as "THF". THF was purchased from Tokyo Chemical Industry Co., Ltd.

[0045] Example 1A (Method of manufacturing cold storage material) First, the reagents shown in Table 1 below were added to a screw tube having a capacity of 60 milliliters to obtain a mixture. The mixture was thoroughly stirred in the screw tube to obtain the cooling material according to Example 1A. (Table 1) Silver phosphate 0.0419 g (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles)

[0046] The screw cap was a glass tube with a threaded cap.

[0047] (Melt point and crystallization temperature measurements) The screw tube containing the cold storage material (about 6 grams) according to Example 1A was placed inside a thermostatic chamber (manufactured by Espec Corporation, product name: SU-241). A thermocouple was attached to the screw tube to monitor the temperature inside the screw tube. The thermostatic chamber was maintained at 20 degrees Celsius for 2 hours. The temperature of the thermostatic chamber was then decreased at a rate of 1 degree Celsius per minute. After the temperature of the thermostatic chamber reached 4 degrees Celsius, the thermostatic chamber was maintained at 4 degrees Celsius for 30 minutes.

[0048] The temperature of the thermostatic chamber was then decreased from 4 degrees Celsius to minus 20 degrees Celsius at a rate of 1 degree Celsius per 24 hours. The temperature of the cold storage material according to Example 1A placed in the thermostatic chamber was recorded using a thermocouple and a data logger (manufactured by Keyence Corporation, product name: NR-600). The crystallization temperature of the cold storage material according to Example 1A was calculated from the temperature of the cold storage material after the temperature of the cold storage material was rapidly increased (see section C in FIG. 1) and the melting point (described in the next paragraph).

[0049] The cold storage material according to Example 1A placed in a thermostatic chamber was maintained at minus 20 degrees Celsius for 3 hours. The temperature of the thermostatic chamber was then increased at a rate of 1 degree Celsius per minute. The melting point of the cold storage material according to Example 1A was measured using a differential scanning calorimeter (also called "DSC"). As a result, the melting point of the cold storage material according to Example 1A was 4.5 degrees Celsius.

[0050] Example 1B In Example 1B, an experiment similar to that of Example 1A was conducted, except that the reagents shown in Table 2 below were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 2) Silver phosphate 0.010 g (2.39 x 10 -5 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0051] Example 1C In Example 1C, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 3 below were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 3) Silver phosphate 0.001 g (2.39 x 10 -6 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0052] Example 1D In Example 1D, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 4 below were mixed instead of those shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of a screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 4) 5.00 grams of cooling material according to Example 1C 18.117 grams of THF (equivalent to approximately 0.251 moles) 76.883 grams of pure water (equivalent to approximately 4.27 moles)

[0053] Example 2A In Example 2A, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 5 below were used instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 5) Silver carbonate 0.0276 grams (1.00 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles)

[0054] Example 2B In Example 2B, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 6 below were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 6) Silver carbonate 0.01 g (3.63 x 10 -5 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0055] Example 2C In Example 2C, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 7 below were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 7) Silver carbonate 0.001 g (3.63 x 10 -6 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0056] Example 2D In Example 2D, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 8 below were mixed instead of those shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of a screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 8) 20.00 grams of cooling material according to Example 2C 15.257 grams of THF (equivalent to approximately 0.212 moles) 64.743 grams of pure water (equivalent to approximately 3.60 moles)

[0057] Example 3A In Example 3A, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 9 below were used instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 9) Silver oxide 0.0124 grams (1.00 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles)

[0058] Example 3B In Example 3B, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 10 were used instead of those shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 10) Silver oxide 0.01 g (8.07 x 10 -5 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0059] Example 3C In Example 3C, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 11 below were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 11) Silver oxide 0.001 g (8.07 x 10 -6 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0060] Example 3D In Example 3D, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 1 were mixed with those shown in Table 12 below instead of those shown in Table 1, and a screw tube with a capacity of 110 milliliters was used instead of a screw tube with a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 12) 20.0 grams of cooling material according to Example 3C 15.257 grams of THF (equivalent to approximately 0.212 moles) 64.743 grams of pure water (equivalent to approximately 3.60 moles)

[0061] (Reference Example 1A) In Reference Example 1A, an experiment was carried out similarly to Example 1A, except that the reagents shown in Table 13 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 13) Silver fluoride 0.0127 grams (1.00 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles)

[0062] (Reference example 1B) In Reference Example 1B, an experiment was carried out similarly to Example 1A, except that the reagents shown in Table 14 were used instead of those shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 14) Silver fluoride 0.01 g (7.88 x 10 -5 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0063] (Reference example 1C) In Reference Example 1C, an experiment was carried out similarly to Example 1A, except that the reagents shown in Table 15 were used instead of the reagents shown in Table 1, and a screw tube having a capacity of 110 milliliters was used instead of the screw tube having a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 15) Silver fluoride 0.001 g (7.88 x 10 -6 (equivalent to moles) 19.071 grams of THF (equivalent to approximately 0.264 moles) 80.929 grams of pure water (equivalent to approximately 4.50 moles)

[0064] (Reference Example 1D) In Reference Example 1D, an experiment was carried out similarly to Example 1A, except that the reagents shown in Table 1 were mixed with those shown in Table 16 below instead of those shown in Table 1, and a screw tube with a capacity of 110 milliliters was used instead of a screw tube with a capacity of 60 milliliters. The results of the experiment are shown in Table 27. (Table 16) 50.0 grams of cooling material according to Reference Example 1C 9.535 grams of THF (equivalent to approximately 0.132 moles) 40.465 grams of pure water (equivalent to approximately 2.25 moles)

[0065] (Reference example 2) In Reference Example 2, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 17 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 17) Silver phosphate 0.0419 g (1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 5.407 grams of heavy water (equivalent to approximately 0.270 moles) Note that in Reference Example 2, the water was deuterium oxide.

[0066] Comparative Example 1 In Comparative Example 1, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 18 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 18) Silver iodide 0.0235 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Silver iodide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0067] Comparative Example 2 In Comparative Example 2, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 19 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 19) Silver bromide 0.0188 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Silver bromide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0068] Comparative Example 3 In Comparative Example 3, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 20 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 20) Silver chloride 0.0143 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Silver chloride was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0069] Comparative Example 4 In Comparative Example 4, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 21 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 21) Titanium dioxide 0.008 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Titanium oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0070] Comparative Example 5 In Comparative Example 5, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 22 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 22) Vanadium oxide 0.0182 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Vanadium oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0071] Comparative Example 6 In Comparative Example 6, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 23 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 23) Iron oxide 0.0160 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Iron oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0072] Comparative Example 7 In Comparative Example 7, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 24 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 24) Nickel oxide 0.0074 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Nickel oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0073] Comparative Example 8 In Comparative Example 8, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 25 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 25) Manganese oxide 0.0071 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Manganese oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0074] Comparative Example 9 In Comparative Example 9, an experiment similar to that of Example 1A was carried out, except that the reagents shown in Table 26 below were mixed instead of the reagents shown in Table 1. The results of the experiment are shown in Table 27. (Table 26) Zinc oxide 0.0081 grams (0.1 x 10 -4 (equivalent to moles) 1.144 grams of THF (equivalent to approximately 0.0159 moles) 4.856 grams of pure water (equivalent to approximately 0.270 moles) Zinc oxide was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0075] The cold storage materials according to Examples 1A, 2A, and 3A, Reference Example 1A, Reference Example 2, and Comparative Examples 1 to 9 had a volume of approximately 6 milliliters. The cold storage materials according to Examples 1B to 1D, Examples 2B to 2D, Examples 3B to 3D, and Reference Examples 1B to 1D had a volume of approximately 100 milliliters.

[0076] [Table 27]

[0077] As is clear from Examples 1A to 3D, a cold storage material containing THF, water, and at least one silver compound selected from the group consisting of silver phosphate, silver carbonate, and silver oxide has a melting point of 4.5 degrees Celsius and a crystallization temperature of 1 degree Celsius or more and 2 degrees Celsius or less.

[0078] On the other hand, as is clear from Comparative Examples 1 to 3, the cold storage material containing THF, water, and silver halide (excluding silver fluoride) has a melting point of 4.5 degrees Celsius, but a crystallization temperature of minus 7 degrees Celsius or lower.

[0079] As is clear from Comparative Examples 4 to 9, the heat storage material containing THF, water, and metal oxides (excluding silver oxide) has a melting point of 4.5 degrees Celsius, but a crystallization temperature of minus 8 degrees Celsius or lower.

[0080] As described above, the heat storage materials according to Examples 1A to 3D have a higher crystallization temperature than the heat storage materials according to Comparative Examples 1 to 4, and therefore the heat storage materials according to Examples 1A to 3D have a higher crystallization efficiency than the heat storage materials according to Comparative Examples 1 to 4.

[0081] As is clear from a comparison between Examples 1A to 3D, the content of the silver compound in the heat accumulating material does not affect the crystallization temperature. [Industrial Applicability]

[0082] The cold storage material according to the present disclosure may be used for a cooler box suitable for storing and refrigerating liquid medicines or food. [Explanation of symbols]

[0083] 100 Cooler Box 101 Insulation Box 102 Insulated lid 110 Cooling pack 120 Pharmaceuticals

Claims

[Claim 1] A cold storage material, By containing tetrahydrofuran and water, it has a melting point of 2 degrees Celsius or more and 8 degrees Celsius or less, The molar ratio of the tetrahydrofuran to the water is adjusted so that the melting point is 2 degrees Celsius or more and 8 degrees Celsius or less, Chemical formula Ag 3 P.O. 4 Silver phosphate, represented by the chemical formula Ag 2 CO 3 and silver oxide represented by the chemical formula AgO, and the molar ratio of the silver compound to the water is 2.64×10 -8 Above 3.70 x 10 -4 The heat exchanger material has a crystallization temperature of 0 degrees Celsius or more and less than the melting point. Cold storage material.

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