Cold storage material

Abstract

To provide a cold storage material advantageous from a viewpoint to enable long-term cold insulation by cold storage in a limited period while enabling cold storage with a small power consumption.SOLUTION: A cold storage material includes: at least one salt selected from a group comprising a carboxylic acid tetra-n-butylammonium salt and a carboxylic acid tetra-n-butyl phosphonium salt; water; a porous material; a silver compound; and an alcohol. The salt contains an anionic atom group having at least two oxygen atoms. The alcohol contains at least one selected from a group comprising a 3-5C monohydric alcohol and a 3-6C dihydric alcohol. The molar ratio of an alcohol content to a salt content is 0.1-0.9%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a cold storage material.

Background Art

[0002] Patent Document 1 relates to a supercooling release device such as an ice thermal storage device used for air conditioning of buildings or production or processing of foods cooled or refrigerated at ice temperature.

[0003] Patent Document 2 relates to a heat storage agent used for air conditioning equipment such as air conditioning or cooling devices for foods and a method for preparing the heat storage agent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides an advantageous cold storage material from the viewpoint of enabling cold storage with low power consumption and enabling long-term cold preservation by cold storage within a limited time.

Means for Solving the Problems

[0006] The cold storage material in the present disclosure comprises at least one salt selected from the group consisting of tetra-n-butylammonium carboxylate salts and tetra-n-butylphosphonium carboxylate salts, water, a porous substance, a silver compound, and an alcohol, the salt contains an anionic atomic group having two or more oxygen atoms, The alcohol includes at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms. The molar ratio of the alcohol content to the salt content is 0.1 to 0.9%.

Advantages of the Invention

[0007] According to the cold storage material in the present disclosure, rapid cold storage at a small degree of supercooling is possible, and a large cold storage capacity can be ensured at a predetermined cold storage time. As a result, the cold storage material in the present disclosure is advantageous from the viewpoint of enabling cold storage with low power consumption and enabling long-term cold preservation by cold storage within a limited time.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] (Findings and the like that form the basis of the present disclosure) When the present inventor arrived at the present disclosure, certain matters were required for cold storage under narrow operating temperature ranges in the processes of food production or processing and applications such as air conditioning for cooling. Examples of narrow operating temperature range conditions include cold storage at about 5°C and heat release at about 11°C. For example, when applying a semi-clathrate hydrate-based cold storage material to such cold storage, it may be required that supercooling is released at a small degree of supercooling and crystallization is completed. However, in a large-scale cold storage system, heat exchange takes time. For this reason, for cold storage in a large amount of cold storage material, there is a problem that the crystal growth rate is insufficient at a small degree of supercooling and cold storage cannot be completed within a predetermined time. Therefore, in the industry, it has been considered difficult to use a large amount of semi-clathrate hydrate-based cold storage materials for applications that require cold storage under the above narrow operating temperature range conditions.

[0010] Under such circumstances, the inventor of the present invention has repeatedly studied day and night about an additive component that can promote crystal growth in a predetermined cold storage material in which cold storage is performed by crystal growth of semi-class rate hydrate. In the process of such study, the inventor newly discovered that a combination of a porous substance, a silver compound, and a predetermined alcohol can promote crystal growth, and thus came to constitute the subject matter of the present disclosure.

[0011] Therefore, the present disclosure provides an advantageous cold storage material from the viewpoint of enabling cold storage with less power consumption and enabling long-term cold preservation by cold storage within a limited time, comprising at least one salt selected from the group consisting of tetra-n-butylammonium carboxylate and tetra-n-butylphosphonium carboxylate.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters or a redundant description of substantially the same configuration may be omitted. Note that the accompanying drawings and the following description are provided for 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, Embodiment 1 will be described with reference to FIG. 1.

[0014] [1-1. Configuration] The cold storage material in Embodiment 1 includes at least one salt selected from the group consisting of tetra-n-butylammonium carboxylate and tetra-n-butylphosphonium carboxylate, water, a porous substance, a silver compound, and an alcohol. The salt contains an anionic atomic group having two or more oxygen atoms. The alcohol includes at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms. In the cold storage material, the molar ratio of the alcohol content to the salt content is 0.1 to 0.9%.

[0015] In the cold storage of the cold storage material, semi-clathrate hydrates are formed. In this specification, a clathrate hydrate means a crystal formed by host water molecules forming a cage-like crystal through hydrogen bonds and enclosing a guest substance, which is a substance other than water, therein. In addition, a semi-clathrate hydrate is a crystal formed by a guest substance participating in the hydrogen bond network of water molecules. The concentration at which water molecules and guest substances form hydrates without excess or deficiency is called the congruent concentration. In the cold storage material in which clathrate hydrates and semi-clathrate hydrates are formed, the concentration of the guest substance in the cold storage material can be adjusted to the congruent concentration or near the congruent concentration.

[0016] The cold storage material has a predetermined melting point. The melting point of the cold storage material can be measured using a differential scanning calorimeter (DSC), as is well known in the technical field of cold storage materials.

[0017] FIG. 1 is a graph showing the characteristics of a pre-crystallized cold storage material during heat release. In FIG. 1, the horizontal axis and the vertical axis 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, the cold storage material is disposed inside a cold storage tank, and a refrigerant is stored around the cold storage material inside the cold storage tank. The temperature of the refrigerant stored around the cold storage material is adjusted to a temperature below the crystallization temperature so that the temperature of the cold storage material is maintained at a temperature below the crystallization temperature. The refrigerant is, for example, water.

[0018] Next, a high-temperature refrigerant is supplied into the cold storage tank, and the cold storage material is gradually warmed. Refer to section F in FIG. 1. For example, when a high-temperature refrigerant is supplied into the cold storage tank at the end of section E, that is, at the beginning of section F, the temperature around the cold storage material gradually increases.

[0019] When the temperature of the cold storage material reaches the melting point Tm of the cold storage material, the temperature of the cold storage material is maintained near the melting point Tm of the cold storage material. Refer to section G in Figure 1. In the unlikely event that there is no cold storage material inside the cold storage tank, the temperature of the refrigerant stored inside the cold storage tank will rise continuously as shown in section Z in Figure 1. On the other hand, when there is cold storage material inside the cold storage tank, in section G, the temperature of the refrigerant stored inside the cold storage tank is maintained near the melting point Tm of the cold storage material. In this way, the cold storage material exerts a 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 is understood that the longer the time of section G during which the temperature of the cold storage material is maintained near the melting point Tm, the higher the heat release performance of the cold storage material.

[0020] After that, the temperature of the liquefied cold storage material rises so as to be equal to the temperature of the high-temperature refrigerant supplied into the cold storage tank. Refer to section H in Figure 1.

[0021] The cold storage 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 the process of food production or food processing, or in air conditioning for cooling. Condition (I): The cold storage material can store cold at a temperature of about 5°C or higher. Condition (II): The cold storage material can release heat using latent heat at about 11°C and has a latent heat amount of 165 kJ / kg or more.

[0023] Regarding condition (I), for example, in the process of food production or processing, or in air conditioning for cooling, the temperature at which the refrigerant cooled by a refrigerator using late-night power is supplied to the cold storage tank to crystallize the cold storage material for cold storage is about 5°C. If the set temperature of the refrigerator is less than 5°C, there is a possibility that the refrigerant will freeze due to variations in the operating conditions of the refrigerator. It is desirable that condition (I) is satisfied from the viewpoint of preventing the freezing of the refrigerant.

[0024] Regarding condition (II), in the process of food production or processing or in air conditioning for refrigeration, cooling should be carried out at about 11°C. For example, the refrigerant that stores cold using late-night electricity returns to the cold storage tank at a temperature of about 11°C or higher through the circulation path between the cold storage tank and the object to be cooled during the day. It is important that the cold storage material can be cooled and can release heat using latent heat at about 11°C. For example, the melting point of n-pentadecane is 9.9°C, and the latent heat of fusion of n-pentadecane is 164 kJ / kg. Therefore, when condition (II) is satisfied, the cold storage material is likely to be superior in terms of cold storage performance to the cold storage material containing n-pentadecane.

[0025] Thus, according to the cold storage material of the present disclosure, the difference between the cold storage temperature and the heat release temperature can be adjusted to about 6°C. Considering the inevitable supercooling for the cold storage material, the melting point of the cold storage material can be set at a temperature 1°C lower than the heat release temperature according to the usage conditions. Also, it is important that the cold storage temperature is 5°C or more lower than the melting point of the cold storage material. If the cold storage temperature needs to be adjusted to be more than 5°C lower than the melting point of the cold storage material, the power consumption of the refrigerator increases, and it is difficult to say that it is advantageous from the perspective of energy saving.

[0026] In this technical field, the heat of fusion is also called the latent heat.

[0027] In the salt of the cold storage material, the anionic atomic group is not limited to a specific atomic group as long as it has two or more oxygen atoms. The anionic atomic group is, for example, a carboxylic acid (carboxylate ion) having 6 or fewer carbon atoms. The anionic atomic group may contain 2-ethylbutanoate. In this case, the cold storage material is likely to satisfy the above conditions (I) and (II).

[0028] In the cold storage material, the ratio of the content of the above salt to the water content is not limited to a specific value. The ratio is, on a molar basis, for example, 2% or more and 4% or less. In the cold storage material, when water and tetra-n-butylammonium carboxylate salt, or water and tetra-n-butylphosphonium carboxylate salt form a semi-clathrate hydrate without excess or deficiency, the melting point and latent heat of the cold storage material can be maximized. The concentration of the salt when this water and salt form a semi-clathrate hydrate without excess or deficiency is also called the harmonic concentration. When the ratio of the content of the above salt to the water content is 2% or more and 4% or less on a molar basis, the concentration of the salt in the cold storage material is easily adjusted to the harmonic concentration or near the harmonic concentration.

[0029] The porous material is not limited to a specific porous material. In the pores of the porous material, clusters in which water molecules are regularly arranged, derived from the semi-clathrate hydrate generated in cold storage, are likely to exist even after the cold storage material releases heat. In cold storage after heat release, a semi-clathrate hydrate is likely to be generated starting from this cluster.

[0030] The porous material includes, for example, activated carbon. Activated carbon can be obtained relatively inexpensively and can reduce the manufacturing cost of the cold storage material.

[0031] Activated carbon has, for example, a basic surface. For example, after washing the activated carbon taken out from the cold storage material and dispersing it in pure water, if the pH of the dispersion shows basicity, it can be determined that the activated carbon has a basic surface.

[0032] Activated carbon may elute at least one selected from the group consisting of Na and K into the water of the cold storage material, for example. Activated carbon may be one that elutes at least one selected from the group consisting of Na and K into pure water when dispersed in pure water, for example.

[0033] The porous material may be a carbon-based porous material such as mesoporous carbon other than activated carbon.

[0034] The cold storage material may contain dissolved Na. The concentration of Na dissolved in the cold storage material is not limited to a specific value. The concentration is, for example, 3 mg / L or more. At least a part of the Na dissolved in the cold storage material may be derived from activated carbon, which is a porous material.

[0035] The cold storage material may contain dissolved K. The concentration of K dissolved in the cold storage material is not limited to a specific value. The concentration is, for example, 20 mg / L or more. At least a part of the K dissolved in the cold storage material may be derived from activated carbon, which is a porous material.

[0036] The content of the porous material in the cold storage material is not limited to a specific value. The content is, for example, 2 mass% or less. In this case, the condition of (II) is more easily satisfied.

[0037] In the cold storage material, the size of the porous material is not limited to a specific value. The porous material may include, for example, particles having a maximum diameter of 1 mm or more. The porous material may include particles having a maximum diameter of less than 1 mm.

[0038] The porous material is, for example, submerged in the cold storage material in a liquid state. A part of the porous material may be floating in the cold storage material in a liquid state.

[0039] In the cold storage material, the silver compound is not limited to a specific compound. The silver compound is, for example, Ag 2 O, AgO, Ag 2 CO 3 、Ag 3 PO 4 、AgF, Ag 2 SO 4 、Ag 2 CrO 4 、Ag 2 WO 4 、and includes at least one selected from the group consisting of silver carboxylates having 5 or fewer carbon atoms.

[0040] The content of the silver compound in the cold storage material is not limited to a specific value. The ratio of the content of the silver compound to the content of the above salt is, for example, 0.05% or more and 0.10% or less on a molar basis.

[0041] The alcohol in the cold storage material is not limited to a specific alcohol as long as it contains at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms. The number of carbon atoms of the monohydric alcohol may be 3 to 4, and the number of carbon atoms of the dihydric alcohol may be 3 to 4. The alcohol preferably contains at least one selected from the group consisting of 1-propanol, iso-propanol, 1,3-propanediol, 1-butanol, 2-butanol, 1,4-butanediol, 1-pentanol, and 1,6-hexanediol.

[0042] The molar ratio of the content of alcohol to the content of salt in the cold storage material may be 0.1 to 0.8%, may be 0.1 to 0.7%, or may be 0.1 to 0.6%.

[0043] The cold storage material may further contain an additive which is a component other than the above salt, water, porous substance, silver compound, and alcohol. Examples of the additive are a supercooling inhibitor, a thickener, and a preservative.

[0044] The cold storage material may not contain an additive. In other words, the cold storage material may be composed only of the above salt, water, porous substance, silver compound, and the above alcohol.

[0045] The cold storage material can be produced by mixing the above salt, water, porous substance, silver compound, and the above alcohol.

[0046] [1-2. Operation] Regarding the cold storage material in Embodiment 1, its operation and action will be described.

[0047] In the use of the cold storage material, cold storage and cold release are repeated. In cold storage, crystals of the semi-class rate hydrate of the above salt can be generated at a small degree of supercooling. Crystallization can be quickly completed at a temperature slightly below the melting point of the semi-class rate hydrate of the above salt.

[0048] In cold release, decomposition of the semi-class rate hydrate of the above salt occurs. For this reason, in cold release, most of the semi-class rate hydrate of the above salt having a low melting point is likely to decompose at a temperature slightly above the melting point of the semi-class rate hydrate of the above salt. For example, 85% or more of the semi-class rate hydrate of the above salt can decompose at a temperature 1°C or higher than the melting point of the semi-class rate hydrate of the above salt.

[0049] [1-3. Effects, etc.] As described above, in the present embodiment, the cold storage material includes at least one salt selected from the group consisting of tetra-n-butylammonium carboxylate and tetra-n-butylphosphonium carboxylate, water, a porous substance, a silver compound, and an alcohol. The salt contains an anionic atomic group having two or more oxygen atoms. The alcohol contains at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms. In the cold storage material, the molar ratio of the alcohol content to the salt content is 0.1 to 0.9%.

[0050] According to the cold storage material in the present disclosure, rapid cold storage at a small degree of supercooling is possible, and a large cold storage amount can be ensured at a predetermined cold storage time. As a result, the cold storage material in the present disclosure is advantageous from the viewpoint of enabling cold storage with low power consumption and enabling long-term cold preservation by cold storage in a limited time.

[0051] As in this embodiment, the alcohol may contain at least one selected from the group consisting of 1-propanol, iso-propanol, 1,3-propanediol, 1-butanol, 2-butanol, 1,4-butanediol, 1-pentanol, and 1,6-hexanediol. In this case, rapid cold storage at a small degree of supercooling can be more easily achieved, and a large amount of cold storage can be more easily ensured within a predetermined cold storage time.

[0052] As in this embodiment, the porous material may contain activated carbon. In this case, since activated carbon can be obtained at low cost, the manufacturing cost of the cold storage material is likely to be low.

[0053] As in this embodiment, the activated carbon may have a basic surface. In this case, the semi-clathrate hydrate crystals of the above salts are more likely to be formed even at a small degree of supercooling.

[0054] As in this embodiment, for example, at least one selected from the group consisting of Na and K may be eluted into the water of the cold storage material by the activated carbon. In this case, the semi-clathrate hydrate crystals of the above salts are more likely to be formed even at a small degree of supercooling.

[0055] As in this embodiment, Na of 3 mg / L or more may be dissolved in the cold storage material. In this case, the semi-clathrate hydrate crystals of the above salts are more likely to be formed even at a small degree of supercooling.

[0056] As in this embodiment, K of 20 mg / L or more may be dissolved in the cold storage material. In this case, the semi-clathrate hydrate crystals of the above salts are more likely to be formed even at a small degree of supercooling.

[0057] As in this embodiment, the anionic atomic group may be a carboxylic acid (carboxylate ion) having 6 or fewer carbon atoms. In this case, the melting point of the crystal of the semi-class rate hydrate of tetra-n-butylammonium salt or tetra-n-butylphosphonium salt is easily adjusted to about 10°C or lower. In this case, the crystal of the semi-class rate hydrate is more easily generated at a small degree of supercooling. For this reason, rapid cold storage at a small degree of supercooling is possible, and a large amount of cold storage is more easily ensured at a predetermined cold storage time. This is more advantageous from the viewpoint of enabling cold storage with less power consumption and enabling long-term cold preservation by cold storage for a limited time.

[0058] As in this embodiment, the anionic atomic group may be 2-ethylbutanoate. In this case, the decomposition temperatures of the semi-class rate hydrates of tetra-n-butylammonium carboxylate and tetra-n-butylphosphonium carboxylate are about 9.9°C and about 8.3°C, respectively. In addition, the latent heat amounts of the semi-class rate hydrates of tetra-n-butylammonium carboxylate and tetra-n-butylphosphonium carboxylate are about 200 kJ / kg and about 195 kJ / kg, respectively. In this case, the crystal of the semi-class rate hydrate is more easily generated at a small degree of supercooling. In addition, the latent heat amount that can be stored as cold heat in the cold storage material tends to be large. This is more advantageous from the viewpoint of enabling cold storage with less power consumption and enabling long-term cold preservation by cold storage for a limited time.

[0059] As in this embodiment, the silver compound is Ag 2 O, AgO, Ag 2 CO 3 、Ag 3 PO 4 、AgF, Ag 2 SO 4 、Ag 2 CrO 4 、Ag 2 WO 4and may contain at least one selected from the group consisting of silver carboxylates having 5 or fewer carbon atoms. In this case, crystals of the semi-clathrate hydrate of the above salt are more likely to be formed at a small degree of supercooling. Therefore, rapid cold storage at a small degree of supercooling is possible, and a large amount of cold storage is more likely to be ensured at a predetermined cold storage time. This is more advantageous from the viewpoint of enabling cold storage with less power consumption and enabling long-term cold preservation by cold storage in a limited time.

[0060] (Embodiment 2) Hereinafter, Embodiment 2 will be described with reference to FIG. 2.

[0061] FIG. 2 shows a cold storage system 1a in Embodiment 2.

[0062] The cold storage system 1a includes a cold storage tank 10, a refrigerator 20, a cooling target 30, a first circulation path 22, and a second circulation path 32. A refrigerant 11 is stored inside the cold storage tank 10. The refrigerant 11 is, for example, water. The cold storage tank 10 can be disposed, for example, underground in a food factory or a building. A plurality of cold storage modules 12 are disposed inside the cold storage tank 10. The plurality of cold storage modules 12 are immersed in the refrigerant 11. The cold storage module 12 includes, for example, a resin container having a rectangular parallelepiped outer shape and the above-described cold storage material housed inside the container. The thickness of the plate material forming the container is, for example, 3 mm or less. The cold storage material housed inside the container of the cold storage module 12 has a thickness of, for example, 20 mm or less in a solid state.

[0063] As shown in FIG. 2, a plurality of cases 14 are disposed inside the cold storage tank 10. Inside the case 14, a plurality of cold storage modules 12 are disposed at predetermined intervals.

[0064] The first circulation path 22 is arranged between the refrigerator 20 and the cold storage tank 10. For example, a pump (not shown) is arranged in the first circulation path 22. In the cold storage operation of the cold storage system 1a, due to the operation of this pump, the refrigerant 11 circulates between the refrigerator 20 and the cold storage tank 10 through the first circulation path 22 as shown by the solid-line arrow in FIG. 2. Through the heat exchange between the refrigerant 11 cooled by the refrigerator 20 and the cold storage module 12, the cold storage material inside the cold storage module 12 crystallizes, and the latent heat is stored as cold heat. In the cold storage operation of the cold storage system 1a, the refrigerator 20 is operated using, for example, late-night power.

[0065] The second circulation path 32 is arranged between the object to be cooled 30 and the cold storage tank 10. For example, a pump (not shown) is arranged in the second circulation path 32. In the cold release operation of the cold storage system 1a, due to the operation of this pump, the refrigerant 11 circulates between the object to be cooled 30 and the cold storage tank 10 through the second circulation path 32 as shown by the dashed-line arrow in FIG. 2. Through the heat exchange between the refrigerant 11 heated in the object to be cooled 30 and the cold storage module 12, the cold heat stored as latent heat in the cold storage material inside the cold storage module 12 is released to the refrigerant 11, and cold release is performed. The cold release operation of the cold storage system 1a can be performed, for example, during the day when the temperature is likely to rise. The object to be cooled 30 is arranged, for example, at the manufacturing site inside a food factory or indoors in a building. In the cold storage system 1a, not only the sensible heat of the refrigerant 11 but also the latent heat of the cold storage material can be utilized, so the amount of cold heat that can be stored in the cold storage tank 10 is likely to increase.

[0066] The number of cold storage modules 12 arranged inside the cold storage tank 10 is not limited to a specific value. The shape of the cold storage module 12 is not limited to a rectangular parallelepiped shape, and other shapes may be used. The size of the cold storage module 12 is not limited to a specific size. In the cold storage system 1a, the dimensions and shape of the case 14 are not limited to a specific form. In the cold storage system 1a, the case 14 may be omitted, and a plurality of cold storage modules 12 may be directly arranged inside the cold storage tank 10. In order to increase the amount of cold heat that can be stored in the cold storage tank 10, it is advantageous that the volume of the cold storage material existing inside the cold storage tank 10 is large. Considering the balance between the amount of cold heat and the manufacturing cost, the volume of the cold storage material existing inside the cold storage tank 10 can be determined.

[0067] For example, when the cold storage tank 10 is arranged underground in a food factory or a building, it is important that heat exchange is quickly performed between the refrigerant and the cold storage material from the viewpoints of quick cold storage at night and quick cold release during the day. For this reason, it is advantageous that the surface area of the cold storage module 12 is large. For example, it is desirable that the cold storage module 12 is thin and has a small dimension in a specific direction and has a large surface area. For this reason, it is advantageous that the cold storage material housed inside the container of the cold storage module 12 has a small thickness in a solid state. In addition, it is advantageous that the thickness of the plate material forming the container of the cold storage module 12 is small.

[0068] (Appendix) From the above description, the following technologies are disclosed. (Technology 1) At least one salt selected from the group consisting of tetra-n-butylammonium carboxylate salt and tetra-n-butylphosphonium carboxylate salt, water, a porous substance, a silver compound, an alcohol, and the salt contains an anionic atomic group having two or more oxygen atoms, The alcohol contains at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms. The molar ratio of the alcohol content to the salt content is 0.1 to 0.9%. Cold storage material. (Technology 2) The alcohol contains at least one selected from the group consisting of 1-propanol, iso-propanol, 1,3-propanediol, 1-butanol, 2-butanol, 1,4-butanediol, 1-pentanol, and 1,6-hexanediol. The cold storage material according to Technology 1. (Technology 3) The porous material contains activated carbon. The cold storage material according to Technology 1 or 2. (Technology 4) The activated carbon has a basic surface. The cold storage material according to Technology 3. (Technology 5) The activated carbon elutes at least one selected from the group consisting of Na and K into the water. The cold storage material according to Technology 3 or 4. (Technology 6) Na of 3 mg / L or more is dissolved. The cold storage material according to any one of Technologies 1 to 5. (Technology 7) K of 20 mg / L or more is dissolved. The cold storage material according to any one of Technologies 1 to 6. (Technology 8) The atomic group is a carboxylic acid having 6 or fewer carbon atoms. The cold storage material according to any one of Technologies 1 to 7. (Technology 9) The atomic group is 2-ethylbutanoate. The cold storage material according to Technology 8. (Technology 10) The silver compound is Ag 2 O, AgO, Ag 2 CO 3 、Ag3 PO 4 、 AgF, Ag 2 SO 4 、 Ag 2 CrO 4 、 Ag 2 WO 4 、 and at least one selected from the group consisting of silver carboxylates having 5 or fewer carbon atoms, The cold storage material according to any one of Technologies 1 to 9.

Example

[0069] The present disclosure will be described in more detail with reference to the following examples. Note that the present disclosure is not limited to the following examples.

[0070] In this example, tetra-n-butylammonium iodide was purchased from Tokyo Chemical Industry Co., Ltd. Silver nitrate was purchased from Fujifilm Wako Pure Chemical Corporation. Tetra-n-butylammonium 2-ethylbutanoate is abbreviated as "TBA-2-EB". TBA-2-EB was synthesized from the reaction of silver 2-ethylbutanoate and tetra-n-butylammonium iodide. Silver 2-ethylbutanoate was synthesized from the reaction of 2-ethylbutyric acid and silver nitrate. Tetra-n-butylammonium iodide and 2-ethylbutyric acid were purchased from Tokyo Chemical Industry Co., Ltd. Activated carbon A is activated carbon having a basic surface and was Kuraray Coal Activated Carbon for removing harmful gases or malodorous gases purchased from Kuraray Co., Ltd. Ag 2 O was purchased from Fujifilm Wako Pure Chemical Corporation. AgO was purchased from Fujifilm Wako Pure Chemical Corporation. Silver acetate was purchased from Fujifilm Wako Pure Chemical Corporation. AgF was purchased from Sigma-Aldrich Japan K.K. Ag 2 CO 3 was purchased from Fujifilm Wako Pure Chemical Corporation. Silver acetate was purchased from Fujifilm Wako Pure Chemical Corporation. Ag 3 PO 4 was purchased from Sigma-Aldrich Japan K.K. Ag 2 CrO 4 was purchased from Fujifilm Wako Pure Chemical Corporation. Ag 2 WO 4It was purchased from FUJIFILM Wako Pure Chemical Corporation.

[0071] (Example 1) As shown in Table 1, TBA-2-EB, pure water, Ag 2 O, activated carbon A, and 1-propanol were added to a screw tube having a capacity of 9 milliliters to obtain a mixture. The mixture was sufficiently stirred inside the screw tube to obtain the cold storage material according to Example 1. The screw tube was a glass tube having a screw cap. When this cold storage material was in a liquid state, activated carbon A was sinking to the bottom of the glass tube. Activated carbon A contained particles having a maximum diameter of 1 mm or more.

[0072] (Examples 2 to 4) Cold storage materials according to Examples 2, 3, and 4 were obtained in the same manner as in Example 1, except that 1-butanol was added in the amounts shown in Table 1 instead of 1-propanol. When these cold storage materials were in a liquid state, activated carbon A was sinking to the bottom of the glass tube.

[0073] (Example 5) A cold storage material according to Example 5 was obtained in the same manner as in Example 1, except that 1-pentanol was added in the amount shown in Table 1 instead of 1-propanol. When this cold storage material was in a liquid state, activated carbon A was sinking to the bottom of the glass tube.

[0074] (Example 6) A cold storage material according to Example 6 was obtained in the same manner as in Example 1, except that iso-propanol was added in the amount shown in Table 1 instead of 1-propanol. When this cold storage material was in a liquid state, activated carbon A was sinking to the bottom of the glass tube.

[0075] (Example 7) A cold storage material according to Example 7 was obtained in the same manner as in Example 1, except that 2-butanol was added in the amount shown in Table 1 instead of 1-propanol. When these cold storage materials were in a liquid state, activated carbon A was sinking to the bottom of the glass tube.

[0076] (Examples 8 and 9) Except that 1,3 - propanediol was added in the amounts shown in Table 1 instead of 1 - propanol, the cold storage materials according to Examples 8 and 9 were obtained in the same manner as in Example 1. When these cold storage materials were in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0077] (Examples 10 and 11) Except that 1,4 - butanediol was added in the amounts shown in Table 1 instead of 1 - propanol, the cold storage materials according to Examples 10 and 11 were obtained in the same manner as in Example 1. When these cold storage materials were in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0078] (Example 12) Except that 1,6 - hexanediol was added in the amounts shown in Table 1 instead of 1 - propanol, the cold storage material according to Example 12 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0079] (Example 13) Ag 2 Except that AgO was used instead of Ag 2 O and 1 - butanol was used instead of 1 - propanol, and they were added in the amounts shown in Table 1, the cold storage material according to Example 13 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0080] (Example 14) Ag 2 Except that AgO was used instead of Ag 2 O and 1,3 - propanediol was used instead of 1 - propanol, and they were added in the amounts shown in Table 1, the cold storage material according to Example 14 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0081] (Example 15) Ag 2 Except that AgO was used instead of Ag 2 O and 1,4 - butanediol was used instead of 1 - propanol, and they were added in the amounts shown in Table 1, the cold storage material according to Example 15 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0082] (Example 16) Ag 2 Instead of O, Ag 2 CO 3 was added in the amounts shown in Table 1, using 1-butanol instead of 1-propanol, and the cold storage material according to Example 16 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0083] (Example 17) Ag 2 Instead of O, Ag 2 CO 3 was added in the amounts shown in Table 1, using 1,3-propanediol instead of 1-propanol, and the cold storage material according to Example 17 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0084] (Example 18) Ag 2 Instead of O, Ag 2 CO 3 was added in the amounts shown in Table 1, using 1,4-butanediol instead of 1-propanol, and the cold storage material according to Example 18 was obtained in the same manner as in Example 1. When this cold storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0085] (Example 19) Ag 2 Instead of O, silver acetate was used, and 1-butanol was used instead of 1-propanol. The cold storage material according to Example 19 was obtained in the same manner as in Example 1, with the amounts added as shown in Table 1. When this cold storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0086] (Example 20) Ag 2 Instead of O, silver acetate was used, and 1,3-propanediol was used instead of 1-propanol. The cold storage material according to Example 20 was obtained in the same manner as in Example 1, with the amounts added as shown in Table 1. When this cold storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0087] (Example 21) Ag 2 An ice storage material according to Example 21 was obtained in the same manner as in Example 1, except that silver acetate was added in the amounts shown in Table 1 instead of AgO, and 1,4-butanediol was added instead of 1-propanol. When this ice storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0088] (Example 22) Ag 2 Instead of AgO, 3 AgPO 4 was added, and 1,4-butanediol was added instead of 1-propanol in the amounts shown in Table 1. An ice storage material according to Example 22 was obtained in the same manner as in Example 1. When this ice storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0089] (Example 23) Ag 2 Instead of AgO, 2 AgSO 4 was added, and 1,4-butanediol was added instead of 1-propanol in the amounts shown in Table 1. An ice storage material according to Example 23 was obtained in the same manner as in Example 1. When this ice storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0090] (Example 24) Ag 2 An ice storage material according to Example 24 was obtained in the same manner as in Example 1, except that silver fluoride was added instead of AgO, and 1,4-butanediol was added instead of 1-propanol in the amounts shown in Table 1. When this ice storage material was in the liquid state, activated carbon A sank to the bottom of the glass tube.

[0091] (Example 25) Ag 2 Instead of AgO, 2 AgCrO 4A cold storage material according to Example 25 was obtained in the same manner as in Example 1, except that 1,4-butanediol was added in the amounts shown in Table 1 instead of 1-propanol. When this cold storage material was in a liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0092] (Example 26) Ag 2 Instead of O, Ag 2 WO 4 A cold storage material according to Example 26 was obtained in the same manner as in Example 1, except that 1,4-butanediol was added in the amounts shown in Table 1 instead of 1-propanol. When this cold storage material was in a liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0093] (Comparative Example 1) TBA-2-EB, pure water, Ag 2 O, and activated carbon A were added in the amounts shown in Table 3 in the same manner as in Example 1 to obtain a cold storage material according to Comparative Example 1. No alcohol was added to the cold storage material according to Comparative Example 1.

[0094] (Comparative Example 2) TBA-2-EB, pure water, Ag 2 O, and 1,4-butanediol were added in the amounts shown in Table 3 in the same manner as in Example 1 to obtain a cold storage material according to Comparative Example 2. Activated carbon A was not added to the cold storage material according to Comparative Example 2.

[0095] (Comparative Example 3) TBA-2-EB, pure water, activated carbon A, and 1,4-butanediol were added in the amounts shown in Table 3 in the same manner as in Example 1 to obtain a cold storage material according to Comparative Example 3. Ag 2 O was not added.

[0096] (Comparative Example 4) A cold storage material according to Comparative Example 4 was obtained in the same manner as in Example 1, except that ethanol was added in the amounts shown in Table 3 instead of 1-propanol. When this cold storage material was in a liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0097] (Comparative Example 5) A cold storage material according to Comparative Example 5 was obtained in the same manner as in Example 1, except that 1-heptanol was added in the amounts shown in Table 3 instead of 1-propanol. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0098] (Comparative Example 6) A cold storage material according to Comparative Example 6 was obtained in the same manner as in Example 1, except that 1-octanol was added in the amounts shown in Table 3 instead of 1-propanol. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0099] (Comparative Example 7) A cold storage material according to Comparative Example 7 was obtained in the same manner as in Example 1, except that 1,2-ethanediol was added in the amounts shown in Table 3 instead of 1-propanol. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0100] (Comparative Example 8) A cold storage material according to Comparative Example 8 was obtained in the same manner as in Example 1, except that 1,7-heptanediol was added in the amounts shown in Table 3 instead of 1-propanol. When this cold storage material was in the liquid state, activated carbon A had sunk to the bottom of the glass tube.

[0101] (Measurement of melting point and latent heat) Using a differential scanning calorimeter DSC-8500 manufactured by PerkinElmer Japan, differential scanning calorimetry (DSC) was performed on each of about 10 milligram samples obtained from the cold storage materials according to each example and each comparative example. This measurement was carried out with temperature adjustment as programmed in advance. First, the temperature of the reference substance was maintained at 30 degrees Celsius for 10 minutes. Next, the temperature of the reference substance was decreased at a rate of 1 degree Celsius per minute. In this cooling process, the temperature rise associated with the crystallization of the cold storage material was observed as an exothermic peak, and thereafter, the temperature of the cold storage material converged to the programmed temperature. Thereby, it was confirmed that the crystallization of the cold storage material was completed. After the temperature of the reference substance reached -20 degrees Celsius, the temperature of the reference substance was maintained at -20 degrees Celsius for 10 minutes. Thereafter, the temperature of the reference substance was increased from -20 degrees Celsius to 30 degrees Celsius at a rate of 1 degree Celsius per minute. When the melting of the crystallized cold storage material started, heat was absorbed by the latent heat portion, so the temperature rise stagnated. When the melting was completed, it converged to the original programmed temperature rise line. The temperature of the endothermic peak at this time was determined as the melting point of the cold storage material, and the endothermic amount was determined as the latent heat amount of the cold storage material. In this way, using the DSC-8500, the melting point and latent heat amount of the cold storage materials according to each example and each comparative example were measured. The results are shown in Table 3.

[0102] (Performance Evaluation) The cold storage materials according to each example and each comparative example were first heated at 20°C for 1 hour. Next, they were cooled at a temperature 5°C lower than the melting point for 10 hours. Then, they were heated at a temperature 1°C higher than the melting point for 14 hours, and subsequently cooled at a temperature 5°C lower than the melting point for 10 hours. A cycle of a total of 24 hours was repeated 10 times. In the first 1 hour of cooling at a temperature 5°C lower than the melting point in the 24-hour cycle, when the transparent liquid phase completely disappeared in the cold storage material and the entire cold storage material became white or crystallized, this case was visually confirmed 7 times or more during the 10 cycles. When the entire cold storage material was completely crystallized at the 10th hour, the crystallization characteristics were evaluated as "A". When this case was visually confirmed less than 7 times during the 10 cycles and the entire cold storage material was completely crystallized at the 10th hour, the crystallization characteristics were evaluated as "B". Also, when the entire cold storage material did not crystallize during the 10 hours at a temperature 5°C lower than the melting point in the 24-hour cycle, the crystallization characteristics were evaluated as "C".

[0103] (Elution test) Activated carbon A was dispersed in pure water at 20°C at a concentration of 40 g / L to obtain a dispersion. This dispersion was filtered through a syringe filter having a pore size of 0.45 μm to obtain a liquid sample. A small amount of nitric acid was added to this liquid sample, and it was further diluted 100-fold with pure water to obtain an analytical sample α.

[0104] An aqueous solution of ammonium carboxylate was obtained in the same manner as in Example 4 except that activated carbon A and a silver compound were not added. This aqueous solution was filtered through a syringe filter having a pore size of 0.45 μm to obtain a liquid sample. A small amount of nitric acid was added to this liquid sample, and it was further diluted 100-fold with pure water to obtain an analytical sample β.

[0105] An aqueous solution of ammonium carboxylate to which activated carbon A was added was obtained in the same manner as in Example 4 except that a silver compound was not added. This aqueous solution was filtered through a syringe filter having a pore size of 0.45 μm to obtain a liquid sample. A small amount of nitric acid was added to this liquid sample, and it was further diluted 100-fold with pure water to obtain an analytical sample γ.

[0106] Using an inductively coupled plasma mass spectrometer (ICP-MS) Agilent 7700 manufactured by Agilent Technologies, ICP-MS was performed on the above-described analytical samples α, β, and γ, and semi-quantitative analysis was performed for 69 elements from Li to U. As a result, in the analytical sample α, Na was detected at a concentration of 5 mg / L, and K was detected at a concentration of 30 mg / L. In the analytical sample β, the detected concentration of Na was less than 1 mg / L, and Na was not substantially detected. In the analytical sample γ, Na was detected at a concentration of 6 mg / L, and K was detected at a concentration of 40 mg / L. From these results, it was suggested that activated carbon A elutes Na and K into the water of the cold storage material.

[0107] It was shown that the cold storage materials according to the respective examples can rapidly store cold with a small degree of supercooling and can store a large amount of latent heat as cold heat at a predetermined cold storage time. On the other hand, in the cold storage materials according to the respective comparative examples, rapid cold storage with a small degree of supercooling could not be expected, and it was shown that the amount of latent heat that could be stored as cold heat was also unlikely to increase at a predetermined cold storage time.

[0108] As described above, the cold storage materials according to the respective examples can rapidly store cold with a smaller degree of supercooling than the cold storage materials according to the respective comparative examples and can store a large amount of latent heat as cold heat at a predetermined cold storage time. Therefore, the cold storage materials according to the respective examples are advantageous from the viewpoint of enabling cold storage with less power consumption and enabling long-term cold preservation by cold storage in a limited time.

[0109] [Table 1]

[0110] [Table 2]

[0111] [Table 3] [Industrial Applicability]

[0112] The cold storage material of the present disclosure can be used in applications that require cooling or cold preservation, such as food factories and buildings.

Description of Symbols

[0113] 1a Cold storage system 10 Cold storage tank 11 Refrigerant 12 Cold storage module 14 Case 20 Refrigerator 22 First circulation path 30 Object to be cooled 32 Second circulation path

Claims

1. At least one salt selected from the group consisting of tetra-n-butylammonium carboxylate salts and tetra-n-butylphosphonium carboxylate salts, water, a porous material, a silver compound, and an alcohol, wherein the salt contains an anionic atomic group having two or more oxygen atoms, the alcohol contains at least one selected from the group consisting of monohydric alcohols having 3 to 5 carbon atoms and dihydric alcohols having 3 to 6 carbon atoms, the molar ratio of the content of the alcohol to the content of the salt is 0.1 to 0.9%, a cold storage material.

2. The alcohol contains at least one selected from the group consisting of 1-propanol, iso-propanol, 1,3-propanediol, 1-butanol, 2-butanol, 1,4-butanediol, 1-pentanol, and 1,6-hexanediol, The cold storage material according to Claim 1.

3. The porous material contains activated carbon, The cold storage material according to Claim 1.

4. The activated carbon has a basic surface, The cold storage material according to Claim 3.

5. The activated carbon elutes at least one selected from the group consisting of Na and K into the water, The cold storage material according to Claim 3.

6. Na of 3 mg / L or more is dissolved, The cold storage material according to Claim 1.

7. K of 20 mg / L or more is dissolved, The cold storage material according to Claim 1.

8. The atomic group is a carboxylic acid having 6 or fewer carbon atoms, The cold storage material according to Claim 1.

9. The atomic group is 2-ethylbutanoate, The cold storage material according to Claim 1.

10. The silver compound is Ag 2 O, AgO, Ag 2 CO 3 、Ag 3 PO 4 、AgF, Ag 2 SO 4 、Ag 2 CrO 4 、Ag 2 WO 4 and includes at least one selected from the group consisting of silver carboxylates having 5 or fewer carbon atoms The cold storage material according to Claim 1.

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