Latent heat storage material composition

Abstract

To provide a latent heat storage material composition comprising an alum hydrate as a main component, which can exhibit an overcooling inhibition effect more surely at a solidification temperature with a less temperature difference from a melting temperature.SOLUTION: A latent heat storage material composition 1 is obtained by using a latent heat storage material 10 as a main component, which performs heat storage or heat release using input and output of latent heat accompanying a phase change, and mixing it with an additive 20 for adjusting physical properties of the latent heat storage material 10, where the latent heat storage material 10 is an alum hydrate, the additive as a first additive is an overcooling inhibitor 20 which induces crystallization to an alum hydrate in a molten state, and the overcooling inhibitor 20 is a first overcooling inhibitor 21 containing a substance corresponding to calcium silicate or is a second overcooling inhibitor 22 containing a phosphate compound containing calcium ion (Ca2+).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a latent heat storage material composition that stores or releases heat by utilizing the latent heat that is generated during a phase change, and that contains an additive that suppresses the supercooling phenomenon of the latent heat storage material. [Background technology]

[0002] Phase change materials (PCMs) have the physical property of storing or releasing heat by utilizing the latent heat released or absorbed during a phase change. By storing waste heat and other heat in advance and extracting it as needed, energy can be utilized efficiently without waste. Many substances can be used as latent heat storage materials. Among them, alum-based latent heat storage materials, such as ammonium alum dodecahydrate (AlNH4(SO4)2·12H2O) (hereinafter sometimes referred to as "ammonium alum") and potassium alum dodecahydrate (AlK(SO4)2·12H2O) (hereinafter sometimes referred to as "potassium alum"), are particularly promising due to their excellent heat storage performance. Ammonium alum has a melting point of 93.5°C and is solid at room temperature. Above its melting point, it becomes a colorless, transparent liquid. The physical properties of potassium alum are that it has a melting point of 92.5°C and is a white solid at room temperature, but when heated above its melting point it becomes a colorless, transparent liquid.

[0003] On the other hand, latent heat storage materials can sometimes suffer from a supercooling phenomenon, whereby they do not crystallize even when cooled from a molten state to below their freezing point. When this phenomenon occurs, ammonium alum or potassium alum, once melted, remains in the molten state without solidifying and is unable to release latent heat. This makes it impossible to utilize the latent heat stored in ammonium alum or the like over time unless a supercooling prevention measure, such as applying an impact to the melt, is implemented. To prevent this supercooling phenomenon, a supercooling inhibitor is generally blended with the latent heat storage material, as exemplified in Patent Document 1. The supercooling inhibitor is an additive that induces crystallization of the latent heat storage material in the molten state.

[0004] Patent Document 1 is a document related to a patent application filed by the present applicant, and describes a latent heat storage material composition obtained by adding calcium sulfate (CaSO4) as a supercooling inhibitor to a latent heat storage material whose main component is alum hydrate, such as ammonium alum. In Patent Document 1, the latent heat storage material composition more reliably suppresses the occurrence of the supercooling phenomenon in the latent heat storage material during the cooling process from a molten state, and is able to release latent heat. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-020497 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, calcium sulfate certainly has the function of inducing crystallization of a latent heat storage material (alum hydrate) in a molten state. However, even after filing the patent application for Patent Document 1, the applicant has continued to diligently research supercooling prevention agents suitable for latent heat storage materials containing alum hydrate as the main component, and has newly discovered the following problems with the technology of Patent Document 1.

[0007] For example, when latent heat stored in a phase change material is released and utilized in heat demand equipment such as hot water supply equipment or air conditioning equipment for heating and cooling, the equipment requires latent heat in a temperature range from around 80°C to the upper 70°C range, as an example. In addition, there is a particular need for such heat demand equipment to use a phase change material whose main component is potassium alum, which is easy to use.

[0008] However, when a latent heat storage material composition in which calcium sulfate is added as a supercooling inhibitor to a latent heat storage material whose main component is potassium alum is used in such heat demanding equipment, when the latent heat storage material composition is cooled from a molten state to a temperature below the melting point of potassium alum and crystallized, the freezing point of potassium alum falls within a temperature range from around 70°C to the upper 60°C range. Therefore, the temperature difference between the freezing temperature and the melting point (92.5°C) is significantly greater than 20°C.

[0009] In this way, when the temperature difference between the freezing temperature and the melting point exceeds 20°C, the latent heat released from the latent heat storage material composition in the solidified state may be about 10°C lower than the temperature of the latent heat required, depending on the equipment that demands the heat, and a sufficient amount of latent heat may not be supplied to the equipment that demands the heat. Therefore, in order to ensure that the latent heat released from the latent heat storage material composition in the solidified state can be supplied to the equipment that demands the heat in a sufficient amount of heat, it has been necessary to limit the temperature difference between the melting point and the freezing temperature of potassium alum to, for example, at most about 10°C.

[0010] The present invention has been made to solve the above problems, and aims to provide a latent heat storage material composition that can more reliably exert a supercooling suppression effect at a solidification temperature that is smaller in temperature difference from the melting temperature than a latent heat storage material whose main component is alum hydrate. [Means for solving the problem]

[0011] In order to achieve the above object, the latent heat storage material composition according to the present invention has the following configuration. (1) A latent heat storage material composition containing a latent heat storage material as a main component, which stores or releases heat by utilizing the transfer of latent heat accompanying a phase change, and an additive compound for adjusting the physical properties of the latent heat storage material, wherein the latent heat storage material is alum hydrate, and the additive compound is a supercooling inhibitor that induces crystallization of the alum hydrate in a molten state as a first additive, and the supercooling inhibitor is a silicic acid compound that is a substance corresponding to calcium silicate, or calcium ions (Ca 2+) is a phosphate compound containing. (2) In the latent heat storage material composition described in (1), the silicate compound is at least one of calcium metasilicate (CaSiO3), tricalcium silicate (Ca3SiO5), and calcium silicate hydrate. (3) The latent heat storage material composition according to (2) is characterized in that the silicate compound is calcium metasilicate. (4) In the latent heat storage material composition described in (2), the silicate compound is a calcium silicate hydrate classified into the wollastonite group or the tobermorite group. (5) In the latent heat storage material composition described in (4), the calcium silicate hydrate is xonotlite (Ca(SiO 17 )(OH)2), or tobermorite (Ca5(SiO 18 H2·nH2O) (n=4, 8). (6) In the latent heat storage material composition described in (1), the phosphate compound contains the calcium ions (Ca 2+ ) and the anion that binds to it, phosphate ion (PO4 3- ), or hydrogen phosphate ion (HPO4 2- ) is a substance characterized by: (7) In the latent heat storage material composition described in (6), the phosphate compound is at least one of tricalcium phosphate (also known as tricalcium phosphate) (Ca3(PO4)2), calcium pyrophosphate (also known as dicalcium phosphate) (Ca2O7P2), and calcium hydrogen phosphate (also known as dicalcium phosphate) (CaHPO4). (8) In the latent heat storage material composition described in (6), the phosphate compound is calcium glycerophosphate (molecular formula: C3H7CaO6P). (9) The latent heat storage material composition according to (1) is characterized in that a second additive other than the first additive is blended as the additive, and the second additive is a melting point adjuster that adjusts the melting point of the alum hydrate to any temperature as needed. (10) In the latent heat storage material composition described in (9), the melting point adjuster is a substance having the physical property of generating a negative heat of solution when dissolved in the alum hydrate. (11) In the latent heat storage material composition described in (10), the melting point adjuster is erythritol (CH 10 O4), xylitol (C5H 12 O5), or mannitol (C6H 14 O6), and is a substance belonging to the sugar alcohol family. (12) In the latent heat storage material composition described in (10), the melting point adjuster contains at least one of potassium chloride (KCl), calcium chloride hexahydrate (CaCl2·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), and sodium chloride (NaCl). (13) In the latent heat storage material composition according to any one of (1) to (12), the alum hydrate contains at least one of ammonium alum dodecahydrate (AlNH4(SO4)2·12H2O) and potassium alum dodecahydrate (AlK(SO4)2·12H2O). [Effects of the Invention]

[0012] The actions and effects of the latent heat storage material composition of the present invention having the above-mentioned structure will be described below. (1) A latent heat storage material composition containing a latent heat storage material as a main component, which stores or releases heat by utilizing the transfer of latent heat accompanying a phase change, and an additive compound for adjusting the physical properties of the latent heat storage material, wherein the latent heat storage material is alum hydrate, and the additive compound is a supercooling inhibitor that induces crystallization of the alum hydrate in a molten state as a first additive, and the supercooling inhibitor is a silicate compound that is a substance corresponding to calcium silicate, or calcium ions (Ca 2+ ) is a phosphate compound containing.

[0013] Due to this characteristic, such supercooling prevention agents actively contribute to the nucleation of the latent heat storage material necessary for crystallization, and therefore, in the latent heat storage material of the latent heat storage material composition of the present invention, the freezing temperature adjusted by the supercooling prevention agent can be kept within a temperature difference of, for example, around 10 degrees Celsius from the melting temperature of the latent heat storage material alone, which has been considered difficult to achieve until now.

[0014] Therefore, the latent heat storage material composition of the present invention has the excellent effect of being able to more reliably exert a supercooling suppression effect at a solidification temperature that is smaller than the melting temperature, for example, by a few dozen degrees Celsius, compared to latent heat storage materials whose main component is alum hydrate.

[0015] The latent heat storage material composition described in (2) is characterized in that the silicate compound is at least one of calcium metasilicate (CaSiO3), tricalcium silicate (Ca3SiO5), and calcium silicate hydrate. Also, the latent heat storage material composition described in (3) is characterized in that the silicate compound is calcium metasilicate. Also, the latent heat storage material composition described in (4) is characterized in that the silicate compound is calcium silicate hydrate classified in the wollastonite group or the tobermorite group. Also, the latent heat storage material composition described in (5) is characterized in that the calcium silicate hydrate is xonotlite (Ca6(SiO 17 )(OH)2), or tobermorite (Ca5(SiO 18H2·nH2O) (n=4, 8).

[0016] Due to these characteristics, in the process of cooling the latent heat storage material composition of the present invention from a molten state, the deviation between the freezing temperature and melting temperature of the latent heat storage material can be suppressed, and the stored latent heat can be released. Furthermore, in the latent heat storage material composition of the present invention, even if the series of processes of storing latent heat and releasing the stored latent heat are repeated over multiple cycles, the freezing temperature and melting temperature hardly vary from cycle to cycle. Therefore, the latent heat storage material composition of the present invention can be used in a stable state when storing heat or when removing the stored heat as needed, accompanying the phase change between the liquid phase and the solid phase inside and outside the heat storage material-filled container in which it is filled.

[0017] In the latent heat storage material composition described in (6), the phosphate compound contains calcium ions (Ca 2+ ) and the anion that binds to it is called hydrogen phosphate ion (PO4 3- ), or hydrogen phosphate ion (HPO4 2- In addition, in the latent heat storage material composition described in (7), the phosphate compound is at least one of tricalcium phosphate (also known as tricalcium phosphate) (Ca3(PO4)2), calcium pyrophosphate (also known as dicalcium phosphate) (Ca2O7P2), and calcium hydrogen phosphate (also known as dicalcium phosphate) (CaHPO4).

[0018] Due to these characteristics, in the process of cooling the latent heat storage material composition of the present invention from a molten state, the deviation between the freezing temperature and melting temperature of the latent heat storage material can be suppressed, and the stored latent heat can be released. Furthermore, in the latent heat storage material composition of the present invention, even if the series of processes of storing latent heat and releasing the stored latent heat are repeated over multiple cycles, the freezing temperature and melting temperature hardly vary from cycle to cycle. Therefore, the latent heat storage material composition of the present invention can be used in a stable state when storing heat or when removing the stored heat as needed, accompanying the phase change between the liquid phase and the solid phase inside and outside the heat storage material-filled container in which it is filled.

[0019] The latent heat storage material composition according to (8) is characterized in that the phosphate compound is calcium glycerophosphate (molecular formula: C3H7CaO6P).

[0020] Due to this feature, during the process of cooling the latent heat storage material composition of the present invention from a molten state, the deviation between the solidification start temperature and the melting start temperature of the latent heat storage material can be suppressed, and the stored latent heat can be released.

[0021] The latent heat storage material composition described in (9) is characterized in that a second additive other than the first additive is blended as an additive, and the second additive is a melting point adjuster that adjusts the melting point of the alum hydrate to any temperature as needed.

[0022] Due to this feature, in the latent heat storage material composition of the present invention, the occurrence of the supercooling phenomenon in the latent heat storage material can be more reliably suppressed by the supercooling prevention agent, and the melting point of the latent heat storage material can be adjusted to a desired temperature by the melting point adjuster without causing any inhibiting factors in the latent heat storage material composition of the present invention.

[0023] In the latent heat storage material composition described in (10), the melting point adjuster is a substance having a physical property of generating a negative heat of solution when dissolved in alum hydrate.

[0024] Due to this feature, in the latent heat storage material composition of the present invention, the melting point adjuster undergoes an endothermic reaction when dissolved in water of the latent heat storage material. Therefore, even if this melting point adjuster is contained in the latent heat storage material composition of the present invention, the melting point of the latent heat storage material can be adjusted to a desired temperature without adversely affecting the heat storage and heat release performance of the latent heat storage material.

[0025] In the latent heat storage material composition of the present invention, the "substance having the property of generating a negative heat of solution" refers to a substance that absorbs heat from the outside and undergoes an endothermic reaction when a melting point adjuster dissolves in the latent heat storage material. Examples of "substances having the property of generating a negative heat of solution" include "sugar alcohols" such as erythritol, xylitol, and mannitol. Other examples include "chloride substances" such as calcium chloride hexahydrate (CaCl2·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), potassium chloride (KCl), and sodium chloride (NaCl). Additionally, there are "sulfate substances" such as ammonium sulfate ((NH4)2SO4). In addition to cases where at least one or more of the substances that fall under the category of "substances belonging to sugar alcohols" described above is included, cases where at least one or more of the substances that fall under the category of "substances belonging to chlorides" described above or cases where at least one or more of the substances that fall under the category of "substances belonging to sulfates" described above also fall under this category.

[0026] In the latent heat storage material composition described in (11), the melting point adjuster is erythritol (CH 10 O4), xylitol (C5H 12 O5), or mannitol (C6H 14 O6), and is a substance belonging to the sugar alcohol family.

[0027] This feature makes it possible to adjust the melting temperature of the latent heat storage material composition according to the present invention, and also increases the viscosity of the latent heat storage material composition according to the present invention, making it possible to prevent separation of the components of the latent heat storage material composition according to the present invention, such as separation between the latent heat storage material and the supercooling prevention agent due to a density difference between the latent heat storage material and the supercooling prevention agent, or separation between the components of the latent heat storage material itself, which is the main component. Therefore, non-uniformity between the components of the latent heat storage material composition according to the present invention does not occur, and the latent heat storage material composition according to the present invention can be a chemically stable heat storage material.

[0028] In the latent heat storage material composition described in (12), the melting point adjuster contains at least one of potassium chloride (KCl), calcium chloride hexahydrate (CaCl2·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), and sodium chloride (NaCl).

[0029] Due to this characteristic, such a melting point adjuster exhibits an endothermic reaction when dissolved in water of a latent heat storage material, and therefore, even if this melting point adjuster is contained in the latent heat storage material composition of the present invention, it is possible to adjust the melting point of the latent heat storage material to a desired temperature without adversely affecting the heat storage and heat release performance of the latent heat storage material.

[0030] In the latent heat storage material composition described in (13), the alum hydrate contains at least one of ammonium alum dodecahydrate (AlNH4(SO4)2·12H2O) and potassium alum dodecahydrate (AlK(SO4)2·12H2O).

[0031] Due to these characteristics, ammonium alum dodecahydrate and potassium alum dodecahydrate are non-toxic and non-hazardous, and therefore are excellent in terms of safety and hygiene, easy to use, and are widely distributed in the market, easily available, and inexpensive. [Brief explanation of the drawings]

[0032] [Figure 1]FIG. 1 is a diagram showing the components of a latent heat storage material composition according to an embodiment, and is a diagram showing a first latent heat storage material composition in which a supercooling inhibitor is blended as an additive. [Figure 2] FIG. 1 is a diagram showing the components of a latent heat storage material composition according to an embodiment, and is a diagram showing a second latent heat storage material composition in which a supercooling inhibitor and one melting point adjuster are blended as additives. [Figure 3] FIG. 1 is a diagram showing the components of a latent heat storage material composition according to an embodiment, and is a diagram showing a third latent heat storage material composition in which two types of melting point adjusters are blended together with a supercooling inhibitor as an additive. [Figure 4] 1 is a graph showing the conditions of the heating temperature changed in a thermostatic chamber in Experiments 1 and 2 in which the process of storing heat using a latent heat storage material composition and releasing the heat was repeated multiple times. [Figure 5] 1 is a table showing the constituents and the content ratios of the latent heat storage material compositions according to Examples 1 to 6 and Comparative Examples 1 and 2 used in Experiment 1. [Figure 6] 1 is a graph showing the behavior of heat storage that occurred in the first cycle in Experiment 1, in which the process of storing and releasing heat using the latent heat storage material compositions according to Examples 1 to 5 and Comparative Examples 1 and 2 was repeated multiple times. [Figure 7] 8 is a graph showing the behavior of heat dissipation that occurred in the first cycle, following FIG. 6. [Figure 8] 8 is a graph showing the behavior of heat dissipation occurring in the third cycle, following FIG. 7. [Figure 9] 8 is a graph showing the behavior of heat storage that occurred in the fourth cycle. [Figure 10] 1 is a table showing the components and their content ratios of the latent heat storage material compositions according to Examples 1 and 4 and Comparative Examples 1 to 3 in the second experiment 1 conducted to confirm reproducibility. [Figure 11] 1 is a graph showing the behavior of heat release occurring in the second cycle in Experiment 1, in which the process of heat storage and heat release using the latent heat storage material compositions according to Examples 1 and 4 and Comparative Examples 1 to 3 was repeated multiple times. [Figure 12]11, is a graph showing the behavior of heat dissipation that occurred in the sixth cycle. [Figure 13] 1 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 1, in which the process of heat storage and heat release using the latent heat storage material composition of Example 6 was repeated multiple times. [Figure 14] 1 is a table showing the constituents and the content ratios of the latent heat storage material compositions according to Examples 7 to 12 and Comparative Example 1 used in Experiment 2. [Figure 15] 1 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 2, in which the process of heat storage and heat release using the latent heat storage material compositions according to Examples 7 to 12 and Comparative Example 1 was repeated multiple times. [Figure 16] 10 is a graph showing the conditions of the heating temperature changed in a thermostatic chamber in Experiment 3 in which the process of storing heat using a latent heat storage material composition and releasing the heat was repeated multiple times. [Figure 17] 1 is a table showing the constituents and the content ratios of the latent heat storage material compositions according to Examples 13 to 15 used in Experiment 3. [Figure 18] 1 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 3, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 13 to 15 was repeated multiple times. [Figure 19] 18, this is a graph showing the behavior of heat dissipation that occurred in the fourth cycle. [Figure 20] 10 is a graph showing the conditions of the heating temperature changed in a thermostatic chamber in Experiment 4 in which the process of storing heat using a latent heat storage material composition and releasing the heat was repeated in multiple cycles. [Figure 21] 1 is a table showing the constituents and the content ratios of the latent heat storage material compositions according to Examples 16 to 18 used in Experiment 4. [Figure 22] 1 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 4, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 16 to 18 was repeated multiple times. [Figure 23] 23 is a graph showing the behavior of heat dissipation occurring in the fourth cycle, following FIG. 22. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments of the latent heat storage material composition according to the present invention will be described in detail with reference to the drawings. The latent heat storage material composition is used by filling the internal space of a heat storage material storage means in a leak-free manner, liquid-tight and airtight. The latent heat storage material composition temporarily stores heat provided from a heat supply source in a latent heat storage material, and then at the heat demand destination, the thermal energy of the latent heat stored in the latent heat storage material can be utilized with a time lag, and the stored latent heat can be extracted as needed. The latent heat storage material composition can be used by repeating the cycle of heat storage and heat release multiple times.

[0034] The latent heat storage material composition of the present invention is composed primarily of a latent heat storage material that stores or releases heat by utilizing the latent heat transferred during a phase change, and is blended with one or more additives that adjust the physical properties of the latent heat storage material. The latent heat storage material is alum hydrate. Examples of the alum hydrate include at least one of ammonium alum dodecahydrate (AlNH4(SO4)2·12H2O) and potassium alum dodecahydrate (AlK(SO4)2·12H2O).

[0035] The first additive is a supercooling inhibitor that promotes the crystallization of alum hydrate in a molten state. The supercooling inhibitor is, for example, a first supercooling inhibitor targeted at silicate compounds belonging to calcium silicate, such as crystalline substances corresponding to calcium silicate, or a calcium ion (Ca 2+ The second additive to be blended together with the first additive is a melting point adjuster that adjusts the melting point of the alum hydrate to a desired temperature as needed.

[0036] <About the first supercooling prevention agent> The first supercooling prevention agent is at least one of calcium metasilicate, tricalcium silicate, and calcium silicate hydrate, which are examples of crystalline substances among silicate compounds that fall under calcium silicate.

[0037] Calcium metasilicate (CaSiO3) is an anhydrous substance with a molecular weight of 116.16 (g / mol), a melting point of 1540°C, and a density of 2.9 (g / cm 3 ], below its melting point, it is a white solid with a triclinic crystal structure and is insoluble in water. Tricalcium silicate (3CaSiO3) is an anhydrous solid with a molecular weight of 228.32 g / mol, a triclinic crystal structure, and is insoluble in water.

[0038] In calcium silicate hydrate, the crystalline material is a substance classified into the wollastonite group or the tobermorite group. For example, xonotlite is a substance classified into the wollastonite group, and has the rational formula [Ca₆·(SiO₂)], which is composed of calcium oxide (CaO), silicon dioxide (SiO₂), and water (HO) in a composition ratio of 6:6:1. 17 )(OH)2]. Xonotlite (common name: xonotlite-based calcium silicate powder) has a packing density of approximately 0.08 to 0.21 [g / cm 3 ], a white powder, non-flammable, and insoluble in water. Xonotlite has a fibrous (needle) crystal habit.

[0039] In addition to xonotlite, calcium silicate hydrates classified in the wollastonite group include other calcium silicate hydrates, such as calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a composition ratio of 3:6:7, with the rational formula [Ca3(SiO 15 Nekoite is a mineral with the rational formula [Ca )·7H2O]. It is made up of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a composition ratio of 5:9:9. 10 (SiO 16 ) (SiO 15)2·18H2O]. Foshagite is composed of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a ratio of 4:3:1 with the rational formula [Ca4(SiO9)(OH)2]. Foshagite is composed of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a ratio of 9:6:11 with the rational formula [Ca9(SiO 18 Examples include Jennite, which has the rational formula [Ca2(SiO3)(OH)8] and Hillebrandite, which is composed of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a 2:1:1 ratio.

[0040] On the other hand, among calcium silicate hydrates, substances classified into the tobermorite group include, for example, tobermorite. Tobermorite (common name: tobermorite-based calcium silicate powder) has a packing density of about 0.05 to 0.35 g / cm. 3 ], a white powder, non-flammable, insoluble in water. There are two types of tobermorite. One type is composed of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a composition ratio of 5:6:5, with the rational formula [Ca5·(SiO 18 The crystal habit of 11nm tobermorite is strip (plate)-like.

[0041] The other type is composed of calcium oxide (CaO), silicon dioxide (SiO2), and water (H2O) in a composition ratio of 5:6:9, with the rational formula [Ca5·(SiO 18 The crystal habit of 14 nm tobermorite is fibrous.

[0042] Other substances classified into the tobermorite group include C·S·H(I), which has the rational formula [0.8≦Ca / Si≦1.5] and a foil-like crystal habit, and C·S·H(II), which has the rational formula [1.5≦Ca / Si≦2.0] and a fiber-like crystal habit.

[0043] Furthermore, calcium silicate hydrates other than those in the wollastonite group and the tobermorite group can also include substances classified into the gyrolite group. An example of a substance classified into the gyrolite group is a substance having the rational formula [Ca 16 (SiO 20 )3(OH)8·14H2O] and has a layered habit. Gyrolite has the rational formula [Ca 14 (SiO 20 )3(Si 16 O 38 )8·2H2O] and has a layered crystalline habit, known as Truscottite. 20 )3·14H2O] and includes the Z-phase, which has a layered crystal habit.

[0044] <About the second supercooling prevention agent> The second supercooling inhibitor is calcium ions (Ca 2+ ), a phosphate compound containing calcium ions (Ca 2+ ) and the anion that binds to it, phosphate ion (PO4 3- ), or hydrogen phosphate ion (HPO4 2- ) is a substance.

[0045] Specifically, the phosphate compound is tricalcium phosphate (also known as tricalcium phosphate) (Ca3(PO4)2). Tricalcium phosphate is anhydrous, has a molecular weight [g / mol] of 310.18, a melting point of 1670°C, and a density of 3.14 [g / cm 3 ], below its melting point it is an amorphous white solid that is insoluble in water.

[0046] The phosphate compound is calcium pyrophosphate (also known as calcium diphosphate) (Ca2O7P2). Calcium pyrophosphate is anhydrous, has a molecular weight [g / mol] of 254.10, a melting point of 1353°C, and a density of 3.09 [g / cm 3], and below the melting point, it is a solid and insoluble in water. Calcium pyrophosphate dihydrate ((Ca2P2O7)·2H2O) has a molecular weight [g / mol] of 290.14, and below the melting point, it is a solid with a triclinic crystal structure. The phosphate compound is calcium hydrogen phosphate (also known as dibasic calcium phosphate) (CaHPO4). Calcium hydrogen phosphate is anhydrous, has a molecular weight [g / mol] of 136.056, a melting point above 450°C, and a density of 2.89 [g / cm 3 At temperatures below its melting point, it is a white solid with a triclinic crystal structure and is insoluble in water. Calcium phosphate dihydrate ((CaHPO4) 2H2O) has a molecular weight of 172.0 (g / mol) and a density of 2.31 (g / cm 3 ].

[0047] Furthermore, the phosphate compound is calcium glycerophosphate (molecular formula: C3H7CaO6P). Calcium glycerophosphate is anhydrous, has a molecular weight [g / mol] of 210.14, a melting point above 170°C, and is a white solid below the melting point. It is soluble in cold water and sparingly soluble in hot water.

[0048] In addition, calcium ions (Ca 2+ ), such as tricalcium phosphate [Ca3(PO4)2], octacalcium phosphate [Ca8(PO4) 4 (HPO4)2(OH)2], hydroxyapatite [Ca 10 (PO4)6(OH)2], fluorapatite [Ca 10 (PO4)6F2], chlorapatite [Ca 10 (PO4)6Cl2], carbonate apatite (carbonate-containing hydroxyapatite) [Ca 10 -a(PO4)6-b(CO3)c(OH)2-d], carbonate apatite (CO3Ap) type A (hydroxyapatite in which the hydroxyl groups have been replaced with carbonate groups), carbonate apatite (CO3Ap) type B (hydroxyapatite in which the phosphate groups have been replaced with carbonate groups), amorphous calcium phosphate (non-crystalline calcium phosphate) tetracalcium phosphate [Ca4(PO4)2O], etc.

[0049] <Melting point adjuster> The melting point adjuster is, for example, a substance that has the physical property of generating a negative heat of solution when dissolved in alum hydrate (latent heat storage material), and is a first melting point adjuster containing a substance belonging to the sugar alcohols, a second melting point adjuster containing a substance belonging to the sulfates, etc. Specifically, in the case of the first melting point adjuster, the substance belonging to the sugar alcohols is, for example, erythritol (CH 10 O4), xylitol (C5H 12 O5), or mannitol (C6H 14 O6). The second melting point adjuster is, for example, a substance belonging to the chloride group, such as potassium chloride (KCl) or sodium chloride (NaCl). The melting point adjuster may be any substance that contains at least one of the first melting point adjuster or the second melting point adjuster.

[0050] Here, the definition of "a substance having a physical property of generating a negative heat of solution" will be explained. As mentioned above, the latent heat storage material composition is composed of alum hydrate (latent heat storage material) as the main component and at least a supercooling inhibitor blended therein. In this application, a "substance having a physical property of generating a negative heat of solution" is defined as a substance that, when a melting point adjuster dissolves in the latent heat storage material, absorbs heat from the outside and causes an endothermic reaction in this melting point adjuster.

[0051] "Substances with the physical property of generating a negative heat of dissolution" include erythritol, xylitol, mannitol, and, for example, sorbitol (CH 14 O6), lactitol (C 12 H 24 O 11) and other "sugar alcohols." In addition to "sugar alcohols," there are also "chloride" substances such as calcium chloride hexahydrate (CaCl2·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), potassium chloride (KCl), and sodium chloride (NaCl). Additionally, there are "sulfate" substances such as ammonium sulfate ((NH4)2SO4). In addition to containing at least one of the above-mentioned "sugar alcohol" substances, it also includes at least one of the above-mentioned "chloride" substances and at least one of the above-mentioned "sulfate" substances.

[0052] In addition, there are mixtures of any of the above-mentioned "substances belonging to sugar alcohols" and any of the above-mentioned "substances belonging to chlorides." There are also mixtures of any of the above-mentioned "substances belonging to sugar alcohols" and any of the above-mentioned "substances belonging to sulfates." There are also mixtures of any of the above-mentioned "substances belonging to sugar alcohols," any of the above-mentioned "substances belonging to chlorides," and any of the above-mentioned "substances belonging to sulfates" (including mixtures of chlorides and sulfates).

[0053] In addition, although they require careful handling and are not preferred for use as latent heat storage material compositions in this embodiment, for example, ammonium nitrate and potassium chlorate also exhibit endothermic reactions when dissolved in water, and therefore fall under the category of "substances having physical properties that generate negative heats of solution."

[0054] Next, the configuration of the latent heat storage material composition according to the embodiment will be described. Fig. 1 is a diagram showing the components of the latent heat storage material composition according to the embodiment, and is a diagram showing a first latent heat storage material composition in which a supercooling prevention agent is blended with the additive. Fig. 2 is a diagram showing the components of the latent heat storage material composition according to the embodiment, and is a diagram showing a second latent heat storage material composition in which a supercooling prevention agent and one melting point adjuster are blended with the additive. Fig. 3 is a diagram showing the components of the latent heat storage material composition according to the embodiment, and is a diagram showing a third latent heat storage material composition in which a supercooling prevention agent and two melting point adjusters are blended with the additive.

[0055] As shown in FIGS. 1 to 3, the latent heat storage material composition 1 according to the embodiment includes three types: a first latent heat storage material composition (latent heat storage material composition 1A), a second latent heat storage material composition (latent heat storage material composition 1B), and a third latent heat storage material composition (latent heat storage material composition 1C). Latent heat storage material composition 1A comprises a latent heat storage material 10 and a supercooling prevention agent 20. Latent heat storage material composition 1B comprises a latent heat storage material 10, a supercooling prevention agent 20, and one melting point adjuster 30. Latent heat storage material composition 1C comprises a latent heat storage material 10, a supercooling prevention agent 20, and two melting point adjusters 30.

[0056] <About Phase Change Material 10> In this embodiment, the latent heat storage material 10 is potassium alum dodecahydrate (potassium aluminum sulfate dodecahydrate: AlK(SO4)2 12H2O) (potassium alum). Potassium alum has a hydration number of 12, a molecular weight [g / mol] of 474.388, and a density [g / cm 3 ]1.75, melting point 92.5 °C, solid at room temperature, soluble in water. Therefore, even if potassium alum is heated below its melting point, it hardly melts and cannot store latent heat.

[0057] In this embodiment, the latent heat storage material 10 is potassium alum, but the latent heat storage material is not limited to potassium alum. The latent heat storage material may be, for example, ammonium alum dodecahydrate (ammonium aluminum sulfate·12-hydrate: AlNH4(SO4)2·12H2O) (ammonium alum), chrome alum (CrK(SO4)2·12H2O), iron alum (FeNH4(SO4)2·12H2O), etc., and the monovalent cation sulfate M I 2(SO4) and the trivalent cation sulfate M III Any "alum hydrate" that is a hydrate of "alum," which is a double sulfate with 2(SO4)3, is fine.

[0058] The trivalent metal ions contained in "alum" may be, in addition to aluminum ions, chromium ions, and iron ions, metal ions such as cobalt ions and manganese ions. Furthermore, the latent heat storage material may be a mixture containing at least two or more substances belonging to such "alum hydrates," or a heat storage material whose main component is a mixed crystal.

[0059] <About Supercooling Prevention Agent 20> As described above, the supercooling prevention agent 20 is the first supercooling prevention agent 21 (first supercooling prevention agent), which is a calcium silicate-based substance, or the second supercooling prevention agent 22 (second supercooling prevention agent), which is a phosphate compound-based substance.

[0060] The blending ratio of the supercooling prevention agent 20 to the total weight of the latent heat storage material composition 1 is preferably in the range of more than 0 wt % and 10 wt % or less.

[0061] <About Melting Point Adjuster 30> In this embodiment, the melting point adjuster 30 is potassium chloride (first melting point adjuster 31) and mannitol (second melting point adjuster 32). Mannitol has the physical properties of having a hydration number of 12, a molecular weight [g / mol] of 182.17, a melting point of 166 to 168°C, and being soluble in water. Mannitol can adjust the melting temperature of the latent heat storage material composition 1C, and has a thickening property that further increases the viscosity of the latent heat storage material composition 1C.

[0062] <Conducting verification experiments> For the purpose of verifying the significance of the latent heat storage material composition 1 according to this embodiment, the present applicant conducted a total of four experiments (Experiments 1 to 4) to verify the effect of the supercooling prevention agent 20 in eliminating the supercooling phenomenon in the latent heat storage material 10. The following will explain the experiments in order, starting with Experiment 1.

[0063] Fig. 4 is a graph showing the conditions of the heating temperature changed in a thermostatic chamber in Experiments 1 and 2, in which the process of storing heat using a latent heat storage material composition and releasing it was repeated multiple times. Fig. 5 is a table listing the components and their content ratios of the latent heat storage material compositions according to Examples 1 to 6 and Comparative Examples 1 and 2 for the latent heat storage material composition used in Experiment 1. Fig. 10 is a table listing the components and their content ratios of the latent heat storage material compositions according to Examples 1 and 4 and Comparative Examples 1 to 3 for the second Experiment 1, which was conducted to confirm reproducibility.

[0064] (Experiment 1) Experiment 1 uses a latent heat storage material composition in which a supercooling inhibitor is added to a latent heat storage material as a sample, and the latent heat storage material composition 1A(1) according to Examples 1 to 6, the latent heat storage material according to Comparative Example 1, and the latent heat storage material composition according to Comparative Examples 2 and 3 are sealed in an aluminum laminate bag for each storage material. This experiment confirms the release of the supercooling phenomenon for each storage material. As shown in Figures 5 and 10, Experiment 1 was conducted twice to confirm its reproducibility, but the second Experiment 1 added Comparative Example 3 and targeted the latent heat storage material composition 1A according to Examples 1 and 4 and the latent heat storage material compositions according to Comparative Examples 2 and 3, and the conditions other than the number of cycles were the same for both experiments.

[0065] <Experimental Method> In Experiment 1, before the start of the experiment, samples to be used in the experiment (such as the latent heat storage material composition 1 according to Examples 1 to 6 and Comparative Examples 1 to 3) were pretreated. In the pretreatment, powder of the latent heat storage material 10, which is a constituent component of the sample, and powder of the supercooling prevention agent 20, etc. (only the latent heat storage material 10 alone was used in Comparative Example 1) were mixed, and this mixture was heated to 98°C to melt. As a result, in the sample in a molten state, the latent heat storage material 10 and the supercooling prevention agent 20, etc., can be considered to be homogeneously mixed, and the sample in a molten state was cooled to around 30°C to solidify. Thus, at the start of Experiment 1, a solid sample produced through such pretreatment was prepared.

[0066] Then, for each of Examples 1 to 6 and Comparative Examples 1 to 3, 50.5 g of sample (50 g for Comparative Example 1) was filled into an aluminum laminate bag and sealed in a liquid-tight state to prepare a total of 13 sample packs. With a thermocouple attached to the surface of the sample pack, the sample packs for each of Examples 1 to 6 and Comparative Examples 1 to 3 were placed in a sealed state in a thermostatic oven. The temperature inside the thermostatic oven was adjusted to a uniform ambient temperature so that the latent heat storage material composition 1 and the like in the sample packs were approximately 30°C at the start of the experiment. After the start of the experiment, the ambient temperature inside the thermostatic oven was controlled based on a set temperature control program, and the temperature of the sample packs was managed.

[0067] In Experiment 1, a sample pack with a thermocouple attached to its surface was placed in a thermostatic bath under atmospheric pressure, and the temperature increase and decrease processes within one cycle were alternately repeated multiple times (four cycles in the first Experiment 1 and six cycles in the second Experiment 1 in this embodiment) via a high-temperature side insulation process or a low-temperature side insulation process, to observe the behavior of latent heat storage and release associated with the phase change of the latent heat storage material composition 1, etc. in the sample pack. In addition, the melting start temperature and solidification start temperature of the latent heat storage material composition 1, etc. were measured for the temperature increase and decrease process in the first cycle.

[0068] Specifically, as shown in Fig. 4, after the start of the experiment, in the temperature-raising process, the atmospheric temperature in the thermostatic bath was controlled to heat the latent heat storage material composition 1 etc. in the sample pack from about 30°C to 98°C at a temperature-raising rate of 20°C / h. After the temperature-raising process, in the high-temperature side insulation process, the sample pack was kept at 98°C (high-temperature side retention temperature) in the thermostatic bath for 6 hours (high-temperature side insulation process) to completely liquefy the sample.

[0069] After 6 hours had passed, a temperature-lowering process was carried out. In this process, the atmospheric temperature in the thermostatic chamber was controlled to cool the latent heat storage material composition 1 and other components in the sample pack, which had been kept at a high-temperature holding temperature of 98°C, at a temperature-lowering rate of 20°C / h until the temperature reached approximately 30°C. After the temperature-lowering process, in the low-temperature holding process, the sample pack was kept at approximately 30°C (low-temperature holding temperature) in the thermostatic chamber for 6 hours to completely solidify the sample. This series of processes, from the temperature-raising process through the high-temperature holding process and the temperature-lowering process to the low-temperature holding process, was defined as one cycle.

[0070] In Experiment 1, as described above, during one cycle, the sample pack was kept at the low-side temperature for six hours in the low-side insulation process immediately preceding the temperature increase process. Furthermore, the sample pack was kept at the high-side temperature for six hours in the high-side insulation process immediately preceding the temperature decrease process, allowing the sample pack to remain stationary. The reason for leaving the sample pack stationary for six hours in both the low-side and high-side insulation processes was to ensure that the sample containing the supercooling inhibitor had sufficient time to undergo a phase change from liquid to solid and reach a fully solidified state before the temperature increase process, and to ensure that the sample had sufficient time to undergo a phase change from solid to liquid and reach a fully melted state before the temperature decrease process. Thus, if the sample pack was kept stationary for six hours, the sample that had undergone the phase change could fully solidify or melt. Therefore, Experiment 1 was conducted to completely eliminate error factors and abnormal values ​​caused by incomplete melting or solidification of the sample, and to avoid results that would result in over- or underestimation.

[0071] In the subsequent second cycle, after 6 hours had elapsed, the latent heat storage material composition 1 and the like in the sample pack were heated from approximately 30°C to 98°C at a heating rate of 20°C / h, and then, as in the first cycle, the sample pack was kept at a higher temperature of 98°C for 6 hours. Then, the latent heat storage material composition 1 and the like in the sample pack, which had been kept at a higher temperature of 98°C, were cooled at a heating rate of 20°C / h to approximately 30°C, and then the sample pack was kept at a lower temperature of approximately 30°C for 6 hours. This heating and cooling process of the second cycle was repeatedly and continuously carried out from the third cycle onwards.

[0072] In addition, for each sample pack, based on the graphed heating and cooling processes of each cycle, the temperature at which the solid phase begins to change to liquid during the heating process (melting start temperature) and the temperature at which the liquid phase begins to change to solid during the cooling process (solidification start temperature) were detected and confirmed using a thermocouple.

[0073] <Conditions common to Examples 1 to 6 and Comparative Examples 1 to 3> Latent heat storage material: potassium alum dodecahydrate 50g Temperature of the thermostatic chamber: high temperature side temperature 98℃, low temperature side temperature approx. 30℃ <Conditions common to Examples 1 to 6 and Comparative Example 3> Supercooling prevention agent / amount added: 0.5g The content of the supercooling prevention agent in the entire latent heat storage material composition: 1 wt% (Latent heat storage material: supercooling prevention agent = 99:1) <Conditions of Examples 1 to 6> · Composition of latent heat storage material composition 1A(1): latent heat storage material 10 and supercooling prevention agent 20 (first supercooling prevention agent 21 or second supercooling prevention agent 22) <Conditions of Example 1> · First supercooling inhibitor 21; calcium metasilicate <Conditions of Example 2> · First supercooling inhibitor 21; Tobermorite <Conditions of Example 3> · First supercooling inhibitor 21; Xonotlite <Conditions of Example 4> · Second supercooling inhibitor 22; calcium pyrophosphate <Conditions of Example 5> · Second supercooling inhibitor 22; tricalcium phosphate <Conditions of Example 6> · Second supercooling inhibitor 22; calcium glycerophosphate <Conditions of Comparative Example 1> Supercooling inhibitor: None <Conditions of Comparative Example 2> Supercooling prevention agent: anhydrous calcium sulfate (CaSO4) <Conditions of Comparative Example 3> Supercooling prevention agent: calcium stearate (C 36 H 70 CaO4)

[0074] <Result> FIG. 6 is a graph showing the behavior of heat storage occurring in the first cycle in Experiment 1, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 1 to 5 and Comparative Examples 1 and 2 was repeated multiple times. FIG. 7 is a graph showing the behavior of heat release occurring in the first cycle, continuing from FIG. 6. FIG. 8 is a graph showing the behavior of heat release occurring in the third cycle, continuing from FIG. 7. FIG. 9 is a graph showing the behavior of heat storage occurring in the fourth cycle, continuing from FIG. 8. FIG. 11 is a graph showing the behavior of heat release occurring in the second cycle in Experiment 1, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 1 and 4 and Comparative Examples 1 to 3 was repeated multiple times. FIG. 12 is a graph showing the behavior of heat release occurring in the sixth cycle, continuing from FIG. 11. FIG. 13 is a graph showing the behavior of heat release occurring in the first cycle in Experiment 1, in which the process of heat storage and heat release using the latent heat storage material composition of Example 6 was repeated multiple times.

[0075] 6 and 9, in the temperature rising process, the ambient temperature in the thermostatic chamber rose under heating control over time, changing in a substantially linear manner at a temperature rise rate of 20°C / h up to an upper limit of 98°C. After heating in the thermostatic chamber began, the temperature of the latent heat storage material composition 1 etc. (sample) in the sample pack also rose in a substantially linear manner, similar to the fluctuations in the ambient temperature.

[0076] However, when the sample temperature reached a high temperature range approaching the upper limit of 98°C, it began to deviate from the behavior of the ambient temperature, and even as time passed, the sample's temperature did not rise as it had up until then, but instead maintained a roughly constant temperature for a while (latent heat storage phenomenon), changing in a manner that did not follow the temperature changes in the thermostatic chamber. In Experiment 1, the temperature transition continued to change, and based on the time t at which the latent heat storage phenomenon occurred, the sample's temperature began to deviate from the ambient temperature, which had been roughly equivalent up until that point, the temperature Te corresponding to time t was defined as the sample's "initiation temperature of melting."

[0077] 7, 8, and 11 to 13, during the temperature-lowering process, the ambient temperature in the thermostatic chamber decreased over time under cooling control, changing in a substantially linear manner at a temperature-lowering rate of 20°C / h until it reached a lower limit of approximately 30°C. After cooling in the thermostatic chamber began, the temperature of the sample also decreased in a substantially linear manner, similar to the fluctuations in the ambient temperature.

[0078] However, for some samples, when the sample temperature reached the lower limit of approximately 30°C, it began to deviate from the behavior of the ambient temperature change, and even as time passed, the sample temperature did not drop as it had done up until then, but instead maintained a roughly constant temperature (latent heat dissipation phenomenon), changing in a manner that did not follow the temperature changes in the thermostatic chamber. In Experiment 1, the temperature transition continued, and based on the time t at which the sample temperature began to deviate from the ambient temperature, which had been roughly equivalent up until that point, due to the onset of latent heat dissipation, the temperature Tr corresponding to time t was defined as the "solidification start temperature" of the sample.

[0079] <First result> Specifically, in the results of the first experiment 1, in the first cycle of the temperature increase process, as shown in FIG. 6, in Example 1, the melting start temperature Te11 was about 86°C. In Example 2, the melting start temperature Te11 was about 90°C. In Examples 3 to 5, the melting start temperature Te11 was about 88°C. In Comparative Example 1, the melting start temperature Te11 was about 88°C. In Comparative Example 2, the melting start temperature Te11 was about 90°C. Furthermore, in the fourth cycle of the temperature increase process, as shown in FIG. 9, in Example 1, the melting start temperature Te11 was about 86°C. In Examples 2 and 5, the melting start temperature Te11 was about 88°C. In Examples 3 and 4, the melting start temperature Te11 was about 87°C. In Comparative Example 1, the melting start temperature Te11 was about 92°C. In the case of Comparative Example 2, the melting initiation temperature Te11 was about 88°C.

[0080] On the other hand, in the temperature-lowering process of the first cycle, as shown in FIGS. 7 and 13, in Example 1, the solidification start temperature was Tr11a = approximately 78°C. In Examples 2 and 3, the solidification start temperature was Tr11a = approximately 77°C. In Examples 4 and 6, the solidification start temperature was Tr11a = approximately 76°C. In Example 5, the solidification start temperature was Tr11a = approximately 74°C. In Comparative Example 1, the behavior of latent heat dissipation due to the phase change from the molten state to the solid state was not confirmed. In Comparative Example 2, the solidification start temperature was Tr11b = approximately 70°C. Furthermore, in the temperature-lowering process of the third cycle, as shown in FIG. 8, in Examples 1 to 3, the solidification start temperature was Tr11a = approximately 77°C. In Example 4, the solidification start temperature was Tr11a = approximately 76°C. In Example 5, the solidification start temperature was Tr11a = approximately 68°C. The behavior of latent heat dissipation due to the phase change from the molten state to the solid state was not confirmed in the case of Comparative Example 1. In the case of Comparative Example 2, the solidification start temperature was Tr11b=about 67°C.

[0081] <2nd result> In the results of the second experiment 1, in the temperature-reducing process of the second cycle, as shown in FIG. 11, in Example 1, the solidification start temperature Tr12 was approximately 78°C. In Example 4, the solidification start temperature Tr12 was approximately 75°C. In Comparative Example 1, the behavior of latent heat dissipation due to the phase change from the molten state to the solid state was not confirmed. In Comparative Example 2, the solidification start temperature Tr12 was approximately 76°C. In Comparative Example 3, the solidification start temperature Tr12 was approximately 77°C. Furthermore, in the temperature-reducing process of the sixth cycle, as shown in FIG. 12, in Examples 1 and 4, the solidification start temperature Tr16a was approximately 77°C. In Comparative Example 1, the behavior of latent heat dissipation due to the phase change from the molten state to the solid state was not confirmed. In Comparative Examples 2 and 3, the solidification start temperature Tr16b was approximately 69°C.

[0082] <Consideration> When heated above its melting point, a latent heat storage material stores latent heat during a phase change from a solid state to a molten state. When cooled below its melting point, the stored latent heat is released to the outside during the phase change from the molten state to a solid state. From the results of two experiments, the sample of Comparative Example 1 contained no additives and consisted solely of a latent heat storage material (potassium alum). Therefore, when the sample of Comparative Example 1 was cooled to a temperature below its melting point of 92.5°C, the potassium alum, which was originally in a molten state near 100°C, theoretically released its stored latent heat during the phase change to a solid state. This heat release should temporarily increase the temperature of the potassium alum. However, the results of Experiment 1 showed no latent heat release behavior from the sample of Comparative Example 1, indicating that the potassium alum exhibited a supercooling phenomenon, which did not cause a phase change to a solid state, even at temperatures below its melting point of 92.5°C.

[0083] In the case of Comparative Example 2, in the first experiment 1, the temperature was approximately 70°C in the first cycle's temperature drop process, approximately 67°C in the third cycle's temperature drop process, and in the second experiment 1, the temperature was approximately 76°C in the second cycle's temperature drop process, and approximately 69°C in the sixth cycle's temperature drop process, confirming the behavior of the sample starting to release latent heat.However, these solidification initiation temperatures, except for the second cycle when it was approximately 76°C, were more than 22°C lower than the melting point of potassium alum.In addition, when the heat storage and heat release process was repeated over multiple cycles, the solidification initiation temperature varied from cycle to cycle, indicating that the sample did not start to solidify at a stable temperature.

[0084] Furthermore, comparing the temperature rise process of the first cycle (FIG. 6) and the temperature rise process of the fourth cycle (FIG. 9), in the case of Comparative Example 1, the behavior of latent heat storage in the fourth cycle was hardly observed, and in the case of Comparative Example 2, the time for storing latent heat in the fourth cycle was significantly reduced compared to the state in the first cycle. The reason for this is presumably that the supercooling phenomenon occurred in the sample before the temperature rise process was carried out, so the entire sample was not in a completely solidified state, and the temperature rise process was carried out in an incompletely solidified state, and therefore the amount of latent heat stored in the sample due to the phase change from solid to liquid phase was reduced by the amount corresponding to the supercooling phenomenon.

[0085] In contrast, in the cases of Examples 1 to 6, it was confirmed that, in the first cycle of the temperature-lowering process, for any of the supercooling prevention agents, the sample began to release latent heat at a solidification initiation temperature that was approximately 15°C lower than the melting point of potassium alum. This is thought to be because the supercooling prevention agents, which were calcium metasilicate (Example 1), tobermorite (Example 2), xonotlite (Example 3), calcium pyrophosphate (Example 4), tricalcium phosphate (Example 5), and calcium glycerophosphate (Example 6), possess some physical property that promotes the growth of potassium alum crystal nuclei.

[0086] Moreover, in the case of Examples 1 to 4, the solidification start temperature in the temperature-lowering process of the third cycle is almost the same as that in the first cycle. That is, in particular, when calcium metasilicate, tobermorite, xonotlite, and calcium pyrophosphate are used as supercooling inhibitors, these supercooling inhibitors can suppress the deviation from the melting point of potassium alum to about 15°C, and it is presumed that the latent heat storage material compositions 1A(1) according to Examples 1 to 4 have physical properties that allow the cycle of heat storage and heat release to be stably repeated multiple times.

[0087] In particular, when calcium stearate, which can be subjected to multiple heat storage and heat release cycles in a relatively stable state, was added as the supercooling prevention agent in Comparative Example 3, and the results of Experiment 1 were actually confirmed, it was confirmed that for calcium metasilicate (Example 1) and calcium pyrophosphate (Example 4), the samples began to release latent heat at a solidification initiation temperature approximately 16°C lower than the melting point of potassium alum, similar to the results of the first Experiment 1. On the other hand, in the case of Comparative Example 3, the deviation from the melting point of potassium alum was suppressed to approximately 15°C during the cooling process in the second cycle, but by the cooling process in the sixth cycle, the deviation from the melting point of potassium alum had increased to approximately 23°C.

[0088] (Experiment 2) Experiment 2 was an experiment to confirm the elimination of the supercooling phenomenon for each heat storage material using samples in which the latent heat storage material compositions 1A(1) according to Examples 7 to 12 and the latent heat storage material according to Comparative Example 1 were each sealed in an aluminum laminate bag. Fig. 14 is a table listing the components and their content ratios of the latent heat storage material compositions according to Examples 7 to 12 and Comparative Example 1 used in Experiment 2. Experiment 2 was carried out under the conditions shown in Fig. 14 using a latent heat storage material composition in which a supercooling inhibitor was added to a latent heat storage material as a sample, using the same experimental method as in Experiment 1 described above.

[0089] <Conditions common to Examples 7 to 12 and Comparative Example 1> Temperature of the thermostatic chamber: high temperature side temperature 98℃, low temperature side temperature approx. 30℃ Latent heat storage material: potassium alum dodecahydrate 50g <Conditions common to Examples 7 to 12> · Composition of latent heat storage material composition 1A(1): latent heat storage material 10 and supercooling prevention agent 20 (first supercooling prevention agent 21 or second supercooling prevention agent 22) Supercooling prevention agent 20 / addition amount: 5g The content of the supercooling prevention agent 20 in the entire latent heat storage material composition 1A(1): 9.1 wt% (Latent heat storage material 10: supercooling prevention agent 20 = 90.9:9.1) <Conditions of Example 7> · First supercooling inhibitor 21; calcium metasilicate <Conditions of Example 8> · First supercooling inhibitor 21; Tobermorite <Conditions of Example 9> · First supercooling inhibitor 21; Xonotlite <Conditions of Example 10> · Second supercooling inhibitor 22; calcium pyrophosphate <Conditions of Example 11> · Second supercooling inhibitor 22; tricalcium phosphate <Conditions of Example 12> · Second supercooling inhibitor 22; calcium glycerophosphate <Conditions of Comparative Example 1> Supercooling inhibitor: None

[0090] <Result> FIG. 15 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 2, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 7 to 12 and Comparative Example 1 was repeated multiple times.

[0091] In the results of Experiment 2, in the first cycle of the temperature drop process, as shown in FIG. 15, in Example 7, the solidification start temperature was Tr21a = approximately 77°C. In Example 8, the solidification start temperature was Tr21a = approximately 73°C. In Example 9, the solidification start temperature was Tr21a = approximately 75°C. In Example 10, the solidification start temperature was Tr21b = approximately 64°C. In Examples 11 and 12, the solidification start temperature was Tr21a = approximately 75°C. In Comparative Example 1, the behavior of latent heat dissipation due to the phase change from a molten state to a solid state was not confirmed.

[0092] <Consideration> When the results of Experiment 1 (FIG. 7), in which the content of supercooling prevention agent 20 in the entire latent heat storage material composition 1 was 1 wt%, and the results of Experiment 2 (FIG. 15), in which the content was 9.1 wt%, are compared using the same supercooling prevention agent, it can be seen that the solidification start temperatures obtained from the results of Experiment 2 tend to be generally similar to the solidification start temperatures obtained from the results of Experiment 1. However, because the supercooling prevention agent 20 itself does not have heat storage performance, if an excessive amount of supercooling prevention agent 20 is blended, the amount of latent heat stored per volume of latent heat storage material composition 1 will be significantly lower than the amount stored by latent heat storage material 10 alone. Therefore, if the proportion of the supercooling prevention agent 20 in the entire latent heat storage material composition 1 is greater than 0 wt% and less than 10 wt%, the heat storage capacity of the latent heat storage material composition 1 will not decrease significantly, and the latent heat storage material composition 1 can be used appropriately in actual field situations without causing any major problems.

[0093] (Experiment 3) Experiment 3 was an experiment to confirm the elimination of the supercooling phenomenon for each heat storage material using samples of the latent heat storage material compositions 1B(1) according to Examples 13 to 15, each sealed in an aluminum laminate bag. Figure 16 is a graph showing the heating temperature conditions in a thermostatic chamber in Experiment 3, in which the process of heat storage and heat release using a latent heat storage material composition was repeated multiple times. Figure 17 is a table listing the components and their content ratios of the latent heat storage material compositions according to Examples 13 to 15 used in Experiment 3. Experiment 3 was conducted under the conditions shown in Figures 16 and 17 using latent heat storage material compositions prepared by adding a supercooling inhibitor and a melting point adjuster to the latent heat storage material. The same experimental method as in Experiment 1 was used, except for the temperature maintained in the thermostatic chamber.

[0094] <Conditions common to Examples 13 to 15> Temperature of the thermostatic chamber: high temperature side temperature 82℃, low temperature side temperature approx. 30℃ The latent heat storage material composition 1B(1) is composed of a latent heat storage material 10, a supercooling prevention agent 20 (first supercooling prevention agent 21 or second supercooling prevention agent 22), and a melting point adjuster 30 (first melting point adjuster 31). 10g of latent heat storage material; 50g of potassium alum dodecahydrate Supercooling prevention agent 20 / addition amount: 0.5g Melting point adjuster 30g / addition amount: potassium chloride / 5g The content of the supercooling prevention agent 20 in the entire latent heat storage material composition 1B(1): 1 wt% The content of the melting point adjuster 30 in the entire latent heat storage material composition 1B(1): 9 wt% Latent heat storage material 10: supercooling prevention agent 20: melting point adjuster 30 = 90.1:0.9:9 <Conditions of Example 13> · First supercooling inhibitor 21; calcium metasilicate <Conditions of Example 14> · Second supercooling inhibitor 22; calcium pyrophosphate <Conditions of Example 15> · Second supercooling inhibitor 22; tricalcium phosphate

[0095] <Result> FIG. 18 is a graph showing the behavior of heat dissipation that occurred in the first cycle in Experiment 3, and FIG. 19 is a graph following FIG. 18, showing the behavior of heat dissipation that occurred in the fourth cycle.

[0096] In the results of Experiment 3, in the first cycle of the temperature drop process, the solidification start temperature Tr31 was approximately 65°C in Examples 13 to 15, as shown in Figure 18. In addition, in the fourth cycle of the temperature drop process, in Example 13, the solidification start temperature Tr34 was approximately 66°C, as shown in Figure 19. In Examples 14 and 15, the solidification start temperature Tr34 was approximately 65°C.

[0097] <Consideration> The results of Experiment 3 show that even if a type of melting point adjuster 30 is contained in the latent heat storage material composition 1, no inhibitory factors are created in the latent heat storage material composition 1, and the melting point of the latent heat storage material 10 can be adjusted to the desired temperature while more reliably suppressing the occurrence of supercooling in the latent heat storage material 10.

[0098] (Experiment 4) Experiment 4 was an experiment to confirm the elimination of the supercooling phenomenon for each heat storage material using samples of the latent heat storage material compositions 1C(1) according to Examples 16 to 18, each sealed in an aluminum laminate bag. Figure 20 is a graph showing the heating temperature conditions in a thermostatic chamber in Experiment 4, in which the process of heat storage and heat release using a latent heat storage material composition was repeated multiple times. Figure 21 is a table listing the components and their content ratios of the latent heat storage material compositions according to Examples 16 to 18 used in Experiment 4. Experiment 4 was conducted under the conditions shown in Figures 20 and 21 using a latent heat storage material composition prepared by adding a supercooling inhibitor and two melting point adjusters to the latent heat storage material. The experiment was conducted in the same manner as Experiment 1, except for the temperature maintained in the thermostatic chamber.

[0099] <Conditions common to Examples 16 to 18> Temperature of the thermostatic chamber: high temperature side maintained at 88℃, low temperature side maintained at approximately 30℃ The latent heat storage material composition 1C(1) is composed of a latent heat storage material 10, a supercooling prevention agent 20 (a first supercooling prevention agent 21 or a second supercooling prevention agent 22), and a melting point adjuster 30 (a first melting point adjuster 31 and a second melting point adjuster 32). 10g of latent heat storage material; 50g of potassium alum dodecahydrate Supercooling prevention agent 20 / addition amount: 0.5g Melting point adjuster 30 / Addition amount: Potassium chloride / 2.5g, Mannitol / 2.5g The content of the supercooling prevention agent in the total latent heat storage material composition 1C(1): 0.9 wt% The content of the melting point adjuster in the total latent heat storage material composition 1C(1): 9 wt% Latent heat storage material: supercooling prevention agent 20: first melting point adjuster 31: second melting point adjuster 32 = 90.1:0.9:4.5:4.5 <Conditions of Example 16> · First supercooling inhibitor 21; calcium metasilicate <Conditions of Example 17> · Second supercooling inhibitor 22; calcium pyrophosphate <Conditions of Example 18> · Second supercooling inhibitor 22; tricalcium phosphate

[0100] <Result> Fig. 22 is a graph showing the behavior of heat release that occurred in the first cycle in Experiment 4, in which the process of heat storage and heat release using the latent heat storage material compositions of Examples 16 to 18 was repeated multiple times. Fig. 23 is a graph following Fig. 22, showing the behavior of heat release that occurred in the fourth cycle.

[0101] In the results of Experiment 4, in the first cycle of the temperature drop process, as shown in FIG. 22, in Example 16, the solidification start temperature was Tr41 = approximately 66°C. In Examples 17 and 18, the solidification start temperature was Tr41 = approximately 65°C. Furthermore, in the fourth cycle of the temperature drop process, as shown in FIG. 23, in Example 16, the solidification start temperature was Tr44 = approximately 70°C. In Example 17, the solidification start temperature was Tr44 = approximately 68°C. In Example 19, the solidification start temperature was Tr44 = approximately 69°C.

[0102] <Consideration> The results of Experiment 4 show that even if two types of melting point adjuster 30 are contained in latent heat storage material composition 1, as in the results of Experiment 3, no inhibitory factors arise in latent heat storage material composition 1, and the melting point of latent heat storage material 10 can be adjusted to the desired temperature while more reliably suppressing the occurrence of supercooling phenomenon in latent heat storage material 10.

[0103] Next, the functions and effects of the latent heat storage material composition 1 of this embodiment will be described.

[0104] The latent heat storage material composition 1 of this embodiment is a latent heat storage material composition containing a latent heat storage material 10 as a main component, which stores or releases heat by utilizing the inflow and outflow of latent heat accompanying a phase change, and an additive compound that adjusts the physical properties of the latent heat storage material 10. The latent heat storage material 10 is an alum hydrate, and the additive compound is a supercooling inhibitor 20 that induces crystallization of the alum hydrate in a molten state as a first additive. The supercooling inhibitor 20 is a crystalline substance (first supercooling inhibitor 21) corresponding to calcium silicate, or calcium ions (Ca 2+ ) (second supercooling prevention agent 22).

[0105] Due to this characteristic, the supercooling prevention agent 20 actively contributes to the nucleation of the latent heat storage material 10, which is necessary for crystallization, so that in the latent heat storage material 10 of the latent heat storage material composition 1, the solidification start temperature Tr adjusted by the supercooling prevention agent 20 can be reduced to a temperature difference of around 10 degrees Celsius from the melting temperature of the latent heat storage material 10 alone, which has previously been considered difficult to achieve.

[0106] Therefore, the latent heat storage material composition 1 of this embodiment has the excellent effect of being able to more reliably exert a supercooling suppression effect at a solidification temperature that is smaller than the temperature difference from the melting temperature, for example, about 10 degrees Celsius, for a latent heat storage material 10 whose main component is alum hydrate.

[0107] The latent heat storage material composition 1 of this embodiment is characterized in that the crystalline substance constituting the first supercooling prevention agent 21 is at least one of calcium metasilicate (CaSiO3), tricalcium silicate (Ca3SiO5), and calcium silicate hydrate. The latent heat storage material composition 1 of this embodiment is characterized in that the crystalline substance constituting the first supercooling prevention agent 21 is calcium metasilicate. The latent heat storage material composition 1 of this embodiment is characterized in that the crystalline substance constituting the first supercooling prevention agent 21 is a calcium silicate hydrate classified in the wollastonite group or the tobermorite group. The latent heat storage material composition 1 of this embodiment is characterized in that the calcium silicate hydrate constituting the first supercooling prevention agent 21 is xonotlite (Ca6(SiO 17 )(OH)2), or tobermorite (Ca5(SiO 18 H2·nH2O) (n=4, 8).

[0108] Due to these characteristics, in the process of cooling the latent heat storage material composition 1 from a molten state, the deviation between the solidification start temperature Tr and the melting start temperature Te of the latent heat storage material 10 is suppressed, and the stored latent heat can be released. Furthermore, even if the series of processes of storing latent heat and releasing the stored latent heat in the latent heat storage material composition 1 is repeated over multiple cycles, the solidification start temperature Tr and the melting start temperature Te hardly vary from cycle to cycle. Therefore, the latent heat storage material composition 1 can be used in a stable state when storing heat or when removing the stored heat as needed, as it changes between liquid and solid phases inside and outside the heat storage material-filled container in which it is filled.

[0109] In addition, in the latent heat storage material composition 1 of this embodiment, the phosphate compound constituting the second supercooling prevention agent 22 contains calcium ions (Ca 2+ ) and the anion that binds to it, phosphate ion (PO4 3- ), or hydrogen phosphate ion (HPO4 2-In addition, in the latent heat storage material composition 1 of this embodiment, the phosphate compound constituting the second supercooling prevention agent 22 is at least one of tricalcium phosphate (also known as tricalcium phosphate) (Ca3(PO4)2), calcium pyrophosphate (also known as dicalcium phosphate) (Ca2O7P2), and calcium hydrogen phosphate (also known as dicalcium phosphate) (CaHPO4).

[0110] Due to these characteristics, in the process of cooling the latent heat storage material composition 1 from a molten state, the deviation between the solidification start temperature Tr and the melting start temperature Te of the latent heat storage material 10 is suppressed, and the stored latent heat can be released. Furthermore, even if the series of processes of storing latent heat and releasing the stored latent heat in the latent heat storage material composition 1 is repeated over multiple cycles, the solidification start temperature Tr and the melting start temperature Te hardly vary from cycle to cycle. Therefore, the latent heat storage material composition 1 can be used in a stable state when storing heat or when removing the stored heat as needed, as it changes between liquid and solid phases inside and outside the heat storage material-filled container in which it is filled.

[0111] Furthermore, the latent heat storage material composition 1 of this embodiment is characterized in that the phosphate compound constituting the second supercooling prevention agent 22 is calcium glycerophosphate (molecular formula: C3H7CaO6P).

[0112] Due to these characteristics, during the process of cooling the latent heat storage material composition 1 from a molten state, the deviation between the solidification start temperature Tr and the melting start temperature Te of the latent heat storage material 10 can be suppressed, and the stored latent heat can be released.

[0113] Furthermore, the latent heat storage material composition 1 of this embodiment is characterized in that a second additive different from the first additive is blended as an additive, and the second additive is a melting point adjuster 30 that adjusts the melting point of the alum hydrate to any temperature as needed.

[0114] Due to this feature, in the latent heat storage material composition 1, the occurrence of the supercooling phenomenon in the latent heat storage material 10 can be more reliably suppressed by the supercooling prevention agent 20, and the melting point of the latent heat storage material 10 can be adjusted to a desired temperature by the melting point adjuster 30 without any inhibiting factors occurring in the latent heat storage material composition 1.

[0115] Furthermore, in the latent heat storage material composition 1 of this embodiment, the melting point adjuster 30 (first melting point adjuster 31, second melting point adjuster 32) is characterized in that it is a substance having the physical property of generating a negative heat of solution when dissolved in alum hydrate.

[0116] Due to this characteristic, the melting point adjuster 30 exhibits an endothermic reaction when dissolved in the water of the latent heat storage material 10. Therefore, even if the melting point adjuster 30 is contained in the latent heat storage material composition 1, it is possible to adjust the melting point of the latent heat storage material 10 to a desired temperature without adversely affecting the heat storage and heat release performance of the latent heat storage material 10.

[0117] In the latent heat storage material composition 1 of this embodiment, the melting point adjuster 30 is erythritol (CH 10 O4), xylitol (C5H 12 O5), or mannitol (C6H 14 O6), which is a substance belonging to sugar alcohols (second melting point adjuster 32).

[0118] This feature allows the melting temperature of the latent heat storage material composition 1 to be adjusted, and the viscosity of the latent heat storage material composition 1 to be increased, preventing separation of the components of the latent heat storage material composition 1, such as separation between the latent heat storage material 10 and the supercooling prevention agent 20 due to density differences between the latent heat storage material 10 and the supercooling prevention agent 20, or separation between the components of the latent heat storage material 10 itself, which is the main component. Therefore, non-uniformity between the components of the latent heat storage material composition 1 does not occur, and the latent heat storage material composition 1 can be a chemically stable heat storage material. Furthermore, by adding the second melting point adjuster 32 to the latent heat storage material 10, the melting point of the latent heat storage material 10 can be significantly adjusted, and since the melting point adjuster 30 itself also has heat storage performance, the second melting point adjuster 32 contributes to storing a larger amount of latent heat in the latent heat storage material composition 1.

[0119] Furthermore, the latent heat storage material composition 1 of this embodiment is characterized in that the melting point adjuster 30 (first melting point adjuster 31) contains at least one of potassium chloride (KCl), calcium chloride hexahydrate (CaCl2·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), and sodium chloride (NaCl).

[0120] Due to this feature, first melting point adjuster 31 exhibits an endothermic reaction when dissolved in water of latent heat storage material 10. Therefore, even if first melting point adjuster 31 is contained in latent heat storage material composition 1, it is possible to adjust the melting point of latent heat storage material 10 to a desired temperature without adversely affecting the heat storage and heat release performance of latent heat storage material 10.

[0121] Furthermore, the latent heat storage material composition 1 of this embodiment is characterized in that the alum hydrate contains at least one of ammonium alum dodecahydrate (AlNH4(SO4)2·12H2O) and potassium alum dodecahydrate (AlK(SO4)2·12H2O).

[0122] Due to these characteristics, ammonium alum dodecahydrate and potassium alum dodecahydrate are non-toxic and non-hazardous, and therefore are excellent in terms of safety and hygiene, easy to use, and are widely distributed in the market, easily available, and inexpensive.

[0123] The present invention has been described above in accordance with Examples 1 to 18 of the embodiment, but the present invention is not limited to Examples 1 to 18 of the embodiment, and can be modified and applied as appropriate within the scope of the gist of the present invention.

[0124] For example, in the embodiment, Experiments 1 to 4 were conducted using a latent heat storage material composition 1 containing potassium alum as the main component and additives added as the latent heat storage material 10, but in addition to Experiments 1 to 4, the applicant has also conducted multiple other experiments similar to Experiments 1 to 4 using a latent heat storage material composition containing ammonium alum as the main component and additives added. When the results of such other experiments are compared with the results of Experiments 1 to 4, etc., which used potassium alum as the main component, the applicant has confirmed that there is no difference in the experimental results obtained due to the difference in alum hydrate between potassium alum and ammonium alum.

[0125] In addition, in Experiment 3 of the embodiment, the first melting point adjuster 31 was potassium chloride (KCl), but the melting point adjuster can be changed to various other substances besides potassium chloride, such as calcium chloride hexahydrate (CaCl·6H2O), magnesium chloride hexahydrate (MgCl·6H2O), sodium chloride (NaCl), etc. [Explanation of symbols]

[0126] 1,1A,1B,1C Latent heat storage material composition 10 Latent heat storage material 20 Supercooling prevention agent 21 First supercooling inhibitor (supercooling inhibitor) 22 Second supercooling inhibitor (supercooling inhibitor) 30 Melting point adjuster 31 First melting point adjuster (melting point adjuster) 32 Second melting point adjuster (melting point adjuster)

Claims

1. A latent heat storage material composition containing a latent heat storage material as a main component, which stores or releases heat by utilizing the latent heat generated by a phase change, and an additive for adjusting the physical properties of the latent heat storage material, the latent heat storage material is alum hydrate, and the additive is a first additive that is a supercooling inhibitor that induces crystallization of the alum hydrate in a molten state; The supercooling inhibitor is a silicate compound that corresponds to calcium silicate; the silicate compound is at least one of calcium metasilicate (CaSiO 3 ), tricalcium silicate (Ca 3 SiO 5 ), and calcium silicate hydrate; A latent heat storage material composition characterized by:

2. The latent heat storage material composition according to claim 1, The silicate compound is calcium metasilicate; A latent heat storage material composition characterized by:

3. The latent heat storage material composition according to claim 1, the silicate compound is a calcium silicate hydrate classified into the wollastonite group or the tobermorite group; A latent heat storage material composition characterized by:

4. The latent heat storage material composition according to claim 3, The calcium silicate hydrate is xonotlite (Ca ６ (Si ６ O １７ ) (OH) ２ ), or tobermorite (Ca ５ (Si ６ O １８ H ２ ) nH ２ O) (n=4, 8); A latent heat storage material composition characterized by:

5. A latent heat storage material composition comprising a latent heat storage material that stores or releases heat by utilizing the transfer of latent heat accompanying a phase change as a main component, and an additive that adjusts the physical properties of the latent heat storage material, the latent heat storage material is alum hydrate, and the additive is a first additive that is a supercooling inhibitor that induces crystallization of the alum hydrate in a molten state; the supercooling prevention agent is a phosphate compound containing calcium ions (Ca 2+ ); The phosphate compound is a substance in which the anion that binds to the calcium ion (Ca 2+ ) is a phosphate ion (PO 4 3− ) or a hydrogen phosphate ion (HPO 4 2− ); The phosphate compound is tricalcium phosphate (also known as tricalcium phosphate) (Ca ３ (P.O. ４ ) ２ ), calcium pyrophosphate (also known as calcium diphosphate) (Ca ２ O ７ P ２ ), or calcium hydrogen phosphate (also known as dibasic calcium phosphate) (CaHPO ４ ) at least one of the substances, A latent heat storage material composition characterized by:

6. A latent heat storage material composition comprising a latent heat storage material that stores or releases heat by utilizing the transfer of latent heat accompanying a phase change as a main component, and an additive that adjusts the physical properties of the latent heat storage material, the latent heat storage material is alum hydrate, and the additive is a first additive that is a supercooling inhibitor that induces crystallization of the alum hydrate in a molten state; the supercooling prevention agent is a phosphate compound containing calcium ions (Ca 2+ ); The phosphate compound is calcium glycerophosphate (molecular formula: C ３ H ７ CaO ６ P), A latent heat storage material composition characterized by:

7. The latent heat storage material composition according to claim 1, a second additive other than the first additive is blended as the additive, and the second additive is a melting point adjuster that adjusts the melting point of the alum hydrate to a desired temperature; A latent heat storage material composition characterized by:

8. The latent heat storage material composition according to claim 5 or claim 6, a second additive other than the first additive is blended as the additive, and the second additive is a melting point adjuster that adjusts the melting point of the alum hydrate to a desired temperature; A latent heat storage material composition characterized by:

9. The latent heat storage material composition according to claim 7 or claim 8, the melting point adjuster is a substance having a physical property of generating a negative heat of solution when dissolved in the alum hydrate; A latent heat storage material composition characterized by:

10. The latent heat storage material composition according to claim 9, The melting point adjuster is erythritol (C ４ H １０ O ４ ), xylitol (C ５ H １２ O ５ ), or mannitol (C ６ H １４ O ６ ) A substance belonging to the sugar alcohols, containing at least one of the following: A latent heat storage material composition characterized by:

11. The latent heat storage material composition according to claim 9, The melting point adjuster may be potassium chloride (KCl), calcium chloride hexahydrate (CaCl ２ ・6H ２ O), magnesium chloride hexahydrate (MgCl ２ ・6H ２ 0), sodium chloride (NaCl), A latent heat storage material composition characterized by:

12. The latent heat storage material composition according to any one of claims 1 to 11, The alum hydrate is ammonium alum dodecahydrate (AlNH ４ (SO ４ ) ２ ・12H ２ O), or potassium alum dodecahydrate (AlK(SO ４ ) ２ ・12H ２ O) at least one of the following: A latent heat storage material composition characterized by:

Images