Cold storage material and method for manufacturing the same

Abstract

To provide a cool storage material advantageous in view of an increased latent heat amount and a lower melting point.SOLUTION: The cool storage material includes tetra-n-butylammonium carboxylate, water, and 1-propanol. The tetra-n-butylammonium carboxylate is at least one selected from a group consisting of tetra-n-butylammonium-2-methylpropanoate, tetra-n-butylammonium-2-ethylbutanoate and tetra-n-butylammonium-2-propylpentanoate. The ratio of the content of the 1-propanol to the content of the tetra-n-butylammonium carboxylate is 0.2 to 1.8, inclusive, by molar basis.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a cold storage material and a cold storage method. [Background technology]

[0002] Patent Document 1 relates to a heat storage material in which a semiclathrate hydrate is formed by a host substance and a guest substance. This heat storage material contains water as a host substance and a guest substance. The guest substance consists of a cation that is a tetrabutylammonium ion and an anion that is a specific carboxylate ion. Patent Document 1 also describes a cold storage device equipped with this cold storage material.

[0003] Non-Patent Document 1 relates to clathrate hydrates of quaternary ammonium salts and their analogues. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-44095 [Non-patent literature]

[0005] [Non-Patent Document 1] Journal of Structural Chemistry 28 (1987), 394-432 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides a regenerator material that includes tetra-n-butylammonium carboxylate and is advantageous in terms of increasing the amount of latent heat and lowering the melting point. [Means for solving the problem]

[0007] The cold storage material in the present disclosure is at least one tetra-n-butylammonium carboxylate selected from the group consisting of tetra-n-butylammonium-2-methylpropanoate, tetra-n-butylammonium-2-ethylbutanoate, and tetra-n-butylammonium-2-propylpentanoate; Water and 1-propanol, The ratio of the content of the 1-propanol to the content of the tetra-n-butylammonium carboxylate is 0.2 or more and 1.8 or less on a molar basis. [Effects of the Invention]

[0008] According to the cold storage material of the present disclosure, the decomposition temperature of the semiclathrate hydrate is reduced due to the intermolecular interaction between 1-propanol and water molecules, but the crystal structure of the semiclathrate hydrate is stabilized, so the latent heat of the cold storage material increases slightly. Therefore, the cold storage material of the present disclosure is advantageous from the viewpoint of increasing the latent heat and lowering the melting point while including tetra-n-butylammonium carboxylate. [Brief explanation of the drawings]

[0009] [Figure 1] Graph showing characteristics of the cold storage material when it is cooled in the first embodiment [Figure 2] Diagram showing an example of the structure of tetra-n-butylammonium carboxylate [Figure 3] Another example of the structure of tetra-n-butylammonium carboxylate. [Figure 4] A diagram showing yet another example of the structure of tetra-n-butylammonium carboxylate. [Figure 5] A diagram of a cooler box in the second embodiment DETAILED DESCRIPTION OF THE INVENTION

[0010] (Findings that formed the basis of this disclosure) At the time the inventors arrived at the idea of ​​the present disclosure, there was a problem in that adding an additive such as a melting point depressant to adjust the decomposition temperature of semiclathrate hydrate in a cold storage material would reduce the latent heat of the cold storage material. Therefore, the industry first searched for a semiclathrate hydrate with a decomposition temperature suitable for the application. When a suitable semiclathrate hydrate could not be found, it was common to adjust the decomposition temperature of a semiclathrate hydrate with a melting point depressant, thereby allowing for the loss of latent heat.

[0011] Under these circumstances, the inventors searched for suitable additives to increase the latent heat of a regenerator material in which semiclathrate hydrate is formed. In the process, they discovered that adding 1-propanol to a specific regenerator material can lower the melting point of the regenerator material while increasing the latent heat of the regenerator material, which constitutes the subject of the present disclosure. Therefore, the present disclosure provides a regenerator material that contains tetra-n-butylammonium carboxylate and is advantageous in terms of increasing the latent heat and lowering the melting point.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0014] [1-1.Configuration] The cold storage material in the first embodiment includes tetra-n-butylammonium carboxylate, water, and 1-propanol. The tetra-n-butylammonium carboxylate includes at least one selected from the group consisting of tetra-n-butylammonium 2-methylpropanoate, tetra-n-butylammonium 2-ethylbutanoate, and tetra-n-butylammonium 2-propylpentanoate. In the cold storage material, the ratio of the 1-propanol content to the tetra-n-butylammonium carboxylate content is 0.2 or more and 1.8 or less on a molar basis.

[0015] Semiclathrate hydrate is formed during the crystallization of a cold storage material. In this specification, clathrate hydrate refers to a crystal formed when water molecules, which are host molecules, form cage-like crystals through hydrogen bonds, and a guest substance, which is a substance other than water, is enclosed within the cage-like crystal. In addition, semiclathrate hydrate is a crystal formed when a guest substance participates in the hydrogen bond network of water molecules. The concentration at which water molecules and guest substance form a hydrate in just the right amount is called the congruent concentration. In cold storage materials in which clathrate hydrate and semiclathrate hydrate are formed, the concentration of the guest substance in the cold storage material can be adjusted to the congruent concentration or close to the congruent concentration.

[0016] The regenerator material has a predetermined melting point, which can be measured using a differential scanning calorimeter (DSC), as is well known in the regenerator material art.

[0017] Fig. 1 is a graph showing the characteristics of a pre-crystallized cold storage material when it is released to cool. In Fig. 1, the horizontal and vertical axes represent time t and temperature T, respectively. In section E of Fig. 1, 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 at a temperature below the crystallization temperature.

[0018] Next, the cooling material is gradually heated. See section F in Figure 1. For example, if the lid of the cooler box is opened at the end of section E, i.e., the beginning of section F, or if the lid is opened and food or other items are placed in the cooler box, the temperature inside the cooler box will gradually increase.

[0019] When the temperature of the cold storage material reaches its melting point Tm, it is maintained near the melting point Tm. See section G in Figure 1. If there is no cold storage material inside the cooler box, the temperature inside the cooler box will continuously rise as shown in section Z in Figure 1. On the other hand, if there is cold storage material inside the cooler box, the temperature inside the cooler box will be maintained near the melting point Tm of the cold storage material in section G. In this way, the cold storage material exerts its cold storage effect. At the end of section G, the crystals in the cold storage material melt and disappear. As a result, the cold storage material liquefies. It can be understood that the longer the time in section G during which the temperature of the cold storage material is maintained near the melting point Tm, the better the cold storage performance of the cold storage material.

[0020] The temperature of the liquefied regenerator material then rises to equalize with the ambient temperature (see section H in Figure 1).

[0021] The regenerator material can be cooled and reused.

[0022] The cold storage material satisfies, for example, the following conditions (I) and (II): When the cold storage material satisfies these conditions, the cold storage material can be advantageously used in a cooler box for keeping items such as fresh produce and food cool. Condition (I): The melting point of the cold storage material is equal to the appropriate temperature for fresh produce and food, or is several degrees Celsius lower than the appropriate temperature. Condition (II): The latent heat of the regenerator material is 175 kJ / liter (L) or more.

[0023] If the melting point of the ice pack material is higher than or significantly lower than the appropriate temperature for fresh produce and food, the appropriate temperature cannot be maintained for a long period of time when the internal temperature of the cooler box rises in response to the ambient temperature. On the other hand, if the ice pack material satisfies condition (I), and the melting point of the ice pack material is the same as or several degrees lower than the appropriate temperature for fresh produce and food, the appropriate temperature can be maintained for a long period of time.

[0024] When the cold storage material in the first embodiment satisfies the condition (II), the latent heat quantity of the cold storage material in the first embodiment is likely to be equal to or greater than that of other types of cold storage materials, and competitiveness with other types of cold storage materials is likely to be ensured. For example, the latent heat quantity of n-tetradecane, which has a melting point of 5.9°C, is 175 kJ / L, the latent heat quantity of n-pentadecane, which has a melting point of 9.9°C, is 175 kJ / L, and the latent heat quantity of n-hexadecane, which has a melting point of 18.2°C, is 177 kJ / L.

[0025] In the art, the heat of fusion is also called the latent heat.

[0026] An example of tetra-n-butylammonium carboxylate is tetra-n-butylammonium-2-ethylbutanoate, as shown in Figure 2. "Butanoate" is also called butanoate or butanoate. Tetra-n-butylammonium carboxylate may be tetra-n-butylammonium-2-methylpropanoate, as shown in Figure 3. "Propanoate" is also called propanoate or propanoate. Tetra-n-butylammonium carboxylate may be tetra-n-butylammonium-2-n-propylpentanoate, as shown in Figure 4. "Pentanoate" is also called pentanoate or pentanoate.

[0027] In the regenerator material, the ratio of the content of 1-propanol to the content of tetra-n-butylammonium carboxylate is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.7 or more, on a molar basis. The ratio is preferably 1.7 or less, more preferably 1.6 or less, and even more preferably 1.5 or less.

[0028] The melting point of the cold storage material is not limited to a specific value. For example, the melting point of the cold storage material is less than 8.0° C. For example, the melting point of the cold storage material is 2° C. or higher.

[0029] The latent heat capacity of the cold storage material is not limited to a specific value. For example, the latent heat capacity of the cold storage material is greater than the latent heat capacity of a cold storage material containing tetra-n-butylammonium carboxylate and water but not containing 1-propanol. The latent heat capacity of the cold storage material is, for example, greater than 182 kJ / L, preferably 184 kJ / L or more, more preferably 186 kJ / L or more, and even more preferably 188 kJ / L or more. The latent heat capacity of the cold storage material can be adjusted to 200 kJ / L or more.

[0030] In the regenerator material, the ratio of the content of tetra-n-butylammonium carboxylate to the content of water is not limited to a specific value, and the ratio is, for example, 0.02 or more and 0.04 or less on a molar basis.

[0031] The content of 1-propanol in the heat accumulator is not limited to a specific value, as long as the ratio of the content of 1-propanol to the content of tetra-n-butylammonium carboxylate is 0.2 or more and 1.8 or less on a molar basis. For example, the content of 1-propanol in the heat accumulator is 5% or less on a molar basis.

[0032] The heat-storing material may further contain additives other than tetra-n-butylammonium carboxylate, water, and 1-propanol. Examples of the additives include a supercooling inhibitor, a thickener, and a preservative.

[0033] The regenerator material may not contain any additives, that is, the regenerator material may consist only of tetra-n-butylammonium carboxylate, water, and 1-propanol.

[0034] The regenerator material can be made by mixing tetra-n-butylammonium carboxylate, water, and 1-propanol.

[0035] [1-2. Operation] The operation and function of the cold storage material in the first embodiment will be described.

[0036] When using a cold storage material, it is repeatedly cooled and then released. During cold storage, for example, tetra-n-butylammonium carboxylate is surrounded by water molecules, forming a semiclathrate hydrate with a cage structure. In semiclathrate hydrate, not all of the cage structures made of water molecules are filled; some empty cage structures exist. When a certain amount of 1-propanol is present in the cold storage material, the 1-propanol fits into the empty cage structures, stabilizing the crystal structure of the semiclathrate hydrate. In this case, it is thought that the hydroxyl groups of 1-propanol replace the water molecules, and the alkyl chains of 1-propanol enter the cage structure, but the detailed structure is unknown.

[0037] The cage structure of semiclathrate hydrate may include cage structures in which tetra-n-butylammonium carboxylate is not located. It is thought that tetra-n-butylammonium carboxylate causes distortion in the semiclathrate hydrate. In response to this distortion, 1-propanol is placed in the cage structures in which tetra-n-butylammonium carboxylate is not located, which is thought to facilitate stabilization of the crystal structure of the semiclathrate hydrate.

[0038] [1-3. Effects, etc.] As described above, in this embodiment, the cold storage material includes tetra-n-butylammonium carboxylate, water, and 1-propanol. The tetra-n-butylammonium carboxylate includes at least one selected from the group consisting of tetra-n-butylammonium 2-methylpropanoate, tetra-n-butylammonium 2-ethylbutanoate, and tetra-n-butylammonium 2-propylpentanoate. In the cold storage material, the ratio of the 1-propanol content to the tetra-n-butylammonium carboxylate content is 0.2 or more and 1.8 or less on a molar basis.

[0039] This facilitates stabilization of the crystal structure of the semiclathrate hydrate formed during the cold storage of the cold storage material, and facilitates increasing the latent heat while lowering the melting point of the cold storage material. For example, the melting point of the cold storage material can be lowered to less than 8.0°C while increasing the latent heat to more than 182 kJ / L. As a result, for example, the cold storage material can be used to keep things cold at temperatures below 8.0°C for long periods of time.

[0040] As in this embodiment, the tetra-n-butylammonium carboxylate may be tetra-n-butylammonium-2-ethylbutanoate, in which case the crystal structure of the semiclathrate hydrate formed during the cold storage of the cold storage material is more likely to be stabilized, and the melting point of the cold storage material is more likely to be lowered and the amount of latent heat is more likely to be increased.

[0041] In this embodiment, a cold storage method is provided, which includes forming a semiclathrate hydrate having tetra-n-butylammonium carboxylate as a guest substance and water as a host substance. In this cold storage method, the tetra-n-butylammonium carboxylate includes at least one selected from the group consisting of tetra-n-butylammonium 2-methylpropanoate, tetra-n-butylammonium 2-ethylbutanoate, and tetra-n-butylammonium 2-propylpentanoate. In addition, the ratio of the 1-propanol content to the tetra-n-butylammonium carboxylate content is 0.2 to 1.8 on a molar basis.

[0042] (Embodiment 2) Hereinafter, the second embodiment will be described with reference to FIG.

[0043] FIG. 5 shows a cooler box 100 according to the second embodiment.

[0044] Cooler box 100 comprises an insulated box 101 having a bottom (not shown) and sides, and an insulated lid 102 .

[0045] For example, the cold storage material of the first embodiment is arranged along 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 of the insulating lid 102. In Fig. 5, cold storage material packs 110 containing the cold storage material of 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.

[0046] The cold storage material in the first embodiment may be placed 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 in the first embodiment may be placed in the internal space of the cooler box 100 while being contained in a cold storage material pack 110. The internal space of the cooler box 100 is, for example, a 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.

[0047] The cold storage material of the first embodiment may be provided inside at least one selected from the group consisting of the side of the heat-insulating box, the heat-insulating lid of the heat-insulating box, and the heat-insulating box itself. In this case, the cold storage material of the first embodiment may be disposed in a state where it is enclosed in the cold storage material pack 110.

[0048] An object 120, which is at least one selected from the group consisting of fresh produce and food, is placed inside the insulated box 101. For example, an alcoholic beverage is placed inside the insulated box 101 shown in FIG. 5 as the object 120. An example of the alcoholic beverage is sake. An example of the sake is junmai sake or junmai ginjo sake. In order to enjoy the gorgeous aroma and flavor of sake, it is necessary to keep the sake cold at 25°C or below. The cooler box in embodiment 2 is suitable for keeping sake cold because the ice storage material in embodiment 1 can have a melting point of 25°C or below. Fresh produce includes items that require freshness to be maintained, such as medicines, biological tissues, cells, or flowers. [Example]

[0049] The present disclosure will now be described in more detail with reference to the following examples.

[0050] In this example, tetra-n-butylammonium-2-ethylbutanoate is abbreviated as "TBA-2-EB." TBA-2-EB was synthesized by the neutralization reaction of tetrabutylammonium hydroxide and 2-ethylbutyric acid. Tetrabutylammonium hydroxide and 2-ethylbutyric acid were purchased from Tokyo Chemical Industry Co., Ltd.

[0051] Example 1A As shown in Table 1, 1.047 g (approximately 0.0029 mol) of TBA-2-EB, 1.953 g (approximately 0.1085 mol) of pure water, and 0.264 g (approximately 0.0044 mol) of 1-propanol were placed in a 9-milliliter screw tube to obtain a mixture. The screw tube was a glass tube with a screw cap. The mixture was thoroughly stirred inside the screw tube to obtain the heat accumulator material of Example 1A. The ratio of the 1-propanol content to the TBA-2-EB content in the heat accumulator material of Example 1A was 1.5 on a molar basis.

[0052] (Melt point and latent heat measurement) Differential scanning calorimetry (DSC) was performed on approximately 10 milligrams of the ice accumulator of Example 1A using a PerkinElmer DSC-8500 differential scanning calorimeter. The temperature was adjusted as programmed. First, the temperature of the reference material was maintained at 30°C for 10 minutes. Then, the temperature of the reference material was reduced at a rate of 1°C / minute. During the cooling process, a temperature increase associated with crystallization of the ice accumulator material was observed as an exothermic peak. The temperature of the ice accumulator then converged to the programmed temperature. This confirmed the completion of crystallization of the ice accumulator material. After the temperature of the reference material reached minus 20°C, the temperature of the reference material was maintained at minus 20°C for 10 minutes. The temperature of the reference material was then increased from minus 20°C to 30°C at a rate of 1°C / minute. When the crystallized ice accumulator began to melt, the temperature increase stagnated due to the absorption of latent heat. When melting was completed, the temperature returned to the original program temperature rise line. The temperature of the endothermic peak at this time was determined to be the melting point of the cold storage material, and the amount of endothermic heat was determined to be the latent heat of the cold storage material. In this way, the melting point and latent heat of the cold storage material according to Example 1A were measured using the DSC-8500. As a result, the melting point of the cold storage material according to Example 1A was 7.0 degrees Celsius, and the latent heat of the cold storage material according to Example 1A was 191 kJ / L. The results are shown in Table 1.

[0053] Example 1B A cold accumulator according to Example 1B was obtained in the same manner as in Example 1A, except that the amount of 1-propanol added was changed to 0.176 g (approximately 0.0029 mol). The ratio of the 1-propanol content to the TBA-2-EB content in the cold accumulator according to Example 1B was 1.0 on a molar basis. The melting point and latent heat of the cold accumulator according to Example 1B were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0054] Example 1C A cold accumulator according to Example 1C was obtained in the same manner as in Example 1A, except that the amount of 1-propanol added was changed to 0.0352 g (approximately 0.00059 moles). The ratio of the 1-propanol content to the TBA-2-EB content in the cold accumulator according to Example 1B was 0.2 on a molar basis. The melting point and latent heat of the cold accumulator according to Example 1C were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0055] Example 1D A cold accumulator according to Example 1D was obtained in the same manner as in Example 1A, except that the amount of 1-propanol added was changed to 0.317 g (approximately 0.0053 mol). The ratio of the 1-propanol content to the TBA-2-EB content in the cold accumulator according to Example 1D was 1.8 on a molar basis. The melting point and latent heat of the cold accumulator according to Example 1D were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0056] (Comparative Example 1) A cold storage material according to Comparative Example 1 was obtained in the same manner as in Example 1A, except that 1-propanol was not added. The melting point and latent heat of the cold storage material according to Comparative Example 1 were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0057] (Comparative Example 2) A cold accumulator according to Comparative Example 2 was obtained in the same manner as in Example 1A, except that the amount of 1-propanol added was changed to 0.352 g (approximately 0.0059 mol). The ratio of the 1-propanol content to the TBA-2-EB content in the cold accumulator according to Comparative Example 2 was 2.0 on a molar basis. The melting point and latent heat of the cold accumulator according to Comparative Example 2 were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0058] (Comparative Example 3) A cold accumulator according to Comparative Example 3 was obtained in the same manner as in Example 1A, except that the amount of 1-propanol added was changed to 0.529 g (approximately 0.0088 mol). The ratio of the 1-propanol content to the TBA-2-EB content in the cold accumulator according to Comparative Example 3 was 3.0 on a molar basis. The melting point and latent heat of the cold accumulator according to Comparative Example 3 were measured in the same manner as in Example 1A. The results are shown in Table 1.

[0059] Comparative Example 4 A cold accumulator according to Comparative Example 4 was obtained in the same manner as in Example 1A, except that 0.176 g (approximately 0.0029 mol) of 2-propanol was added instead of 1-propanol. The melting point and latent heat of the cold accumulator according to Comparative Example 4 were measured in the same manner as in Example 1A. The results are shown in Table 2.

[0060] (Comparative Example 5) A cold accumulator according to Comparative Example 5 was obtained in the same manner as in Example 1A, except that 0.217 g (approximately 0.0029 mol) of 1-butanol was added instead of 1-propanol. The melting point and latent heat of the cold accumulator according to Comparative Example 5 were measured in the same manner as in Example 1A. The results are shown in Table 2.

[0061] (Comparative Example 6) A cold accumulator according to Comparative Example 6 was obtained in the same manner as in Example 1A, except that 0.217 g (approximately 0.0029 mol) of 2-butanol was added instead of 1-propanol. The melting point and latent heat of the cold accumulator according to Comparative Example 6 were measured in the same manner as in Example 1A. The results are shown in Table 2.

[0062] (Comparative Example 7) A cold accumulator according to Comparative Example 7 was obtained in the same manner as in Example 1A, except that 0.217 g (approximately 0.0029 mol) of isobutyl alcohol was added instead of 1-propanol. The melting point and latent heat of the cold accumulator according to Comparative Example 7 were measured in the same manner as in Example 1A. The results are shown in Table 2.

[0063] (Comparative Example 8) A cold accumulator according to Comparative Example 8 was obtained in the same manner as in Example 1A, except that 0.217 g (approximately 0.0029 mol) of tert-butyl alcohol was added instead of 1-propanol. The melting point and latent heat of the cold accumulator according to Comparative Example 8 were measured in the same manner as in Example 1A. The results are shown in Table 2.

[0064] The melting points and latent heat amounts of the cold storage materials according to each Example and Comparative Examples 2 and 3, to which 1-propanol was added, were compared with the melting point and latent heat amount of the cold storage material according to Comparative Example 1, to which 1-propanol was not added. In addition, the melting points and latent heat amounts of the cold storage materials according to Comparative Examples 4 to 8, to which alcohols other than 1-propanol were added, were compared with the melting point and latent heat amount of the cold storage material according to Comparative Example 1.

[0065] The cold storage materials having a melting point lower than that of the cold storage material according to Comparative Example 1 (8.0°C) and a latent heat amount higher than that of the cold storage material according to Comparative Example 1 (182 kJ / L) were evaluated as "A", and the other cold storage materials were evaluated as "C". The evaluation results are shown in Table 1.

[0066] [Table 1]

[0067] [Table 2]

[0068] As shown in Table 1, the melting points of the examples are lower than that of the cold storage material of Comparative Example 1. In addition, the latent heat of the cold storage material of each example is greater than that of the cold storage material of Comparative Example 1. Therefore, it is understood that in the cold storage material, the ratio of the 1-propanol content to the TBA-2-EB content is 0.2 or more and 1.8 or less on a molar basis, which is advantageous from the viewpoint of increasing the latent heat of the cold storage material and lowering the melting point.

[0069] According to Comparative Examples 2 and 3, when the ratio of the 1-propanol content to the TBA-2-EB content in the cold storage material is 2.0 or more on a molar basis, the melting point of the cold storage material tends to be low. However, in this case, the latent heat amount of the cold storage material is smaller than that of the cold storage material according to Comparative Example 1.

[0070] As shown in Table 2, the latent heat quantities of the cold storage materials according to Comparative Examples 4 to 8 were 140 kJ / L or less, which were lower than the latent heat quantity of the cold storage material according to Comparative Example 1. It can be seen that it is difficult to increase the latent heat quantity of the cold storage material even if 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, or tert-butyl alcohol is added instead of 1-propanol.

[0071] As described above, the cold storage materials according to the examples are advantageous in terms of increasing the amount of latent heat and lowering the melting point compared to the cold storage materials according to the comparative examples, and therefore can provide cold storage materials that are advantageous in keeping a desired temperature for a long period of time. [Industrial Applicability]

[0072] The cold storage material according to the present disclosure can be used for storing, preserving, or transporting objects that require freshness preservation, such as medicines, biological tissues, cells, food, and flowers. [Explanation of symbols]

[0073] 100 Cooler Box 101 Insulation Box 102 Insulated lid 110 Ice pack 120 Objects

Claims

1. tetra-n-butylammonium carboxylates including at least one of tetra-n-butylammonium-2-methylpropanoate, tetra-n-butylammonium-2-ethylbutanoate, and tetra-n-butylammonium-2-propylpentanoate; Water and 1-propanol, the ratio of the content of the 1-propanol to the content of the tetra-n-butylammonium carboxylate is 0.2 or more and 1.8 or less on a molar basis; Cold storage material.

2. 2. The regenerator material according to claim 1, wherein the tetra-n-butylammonium carboxylate is tetra-n-butylammonium 2-ethylbutanoate.

3. A method for producing a cold storage material comprising tetra-n-butylammonium carboxylate, water, and 1-propanol, comprising: mixing the tetra-n-butylammonium carboxylate, the water, and the 1-propanol; the tetra-n-butylammonium carboxylate comprises at least one of tetra-n-butylammonium-2-methylpropanoate, tetra-n-butylammonium-2-ethylbutanoate, and tetra-n-butylammonium-2-propylpentanoate; the ratio of the content of the 1-propanol to the content of the tetra-n-butylammonium carboxylate is 0.2 or more and 1.8 or less on a molar basis; Manufacturing method of cold storage material.

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