Latent heat storage material composition, latent heat storage material molded body, and method for manufacturing the latent heat storage material molded body
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NIPPON SHOKUBAI CO LTD
- Filing Date
- 2023-10-30
- Publication Date
- 2026-06-18
Smart Images
Figure 0007875982000001 
Figure 0007875982000002
Abstract
Description
【Technical Field】 【0001】 The present invention relates to a latent heat storage material composition, a latent heat storage material formed body obtained by molding the same, and a method for manufacturing the latent heat storage material formed body. 【Background Art】 【0002】 As methods for storing heat, sensible heat storage using temperature change (for example, Patent Document 1) and latent heat storage using phase change of a substance (for example, Patent Document 2) are known. Among these, the sensible heat storage technology can store heat at high temperatures, but on the other hand, since it uses only the sensible heat due to the temperature change of the substance, there is a problem that the heat storage density is low. As a method for solving such a problem, a latent heat storage technology that stores heat using latent heat such as molten salt has been proposed. 【0003】 Various types of heat storage bodies used in latent heat storage technology have been proposed. For example, Patent Document 3 discloses a latent heat storage capsule characterized in that a single-layer, double-layer or triple-layer metal film is formed on the surface of a latent heat storage material, and a method for manufacturing a latent heat storage capsule characterized in that a metal film is coated on a latent heat storage material by an electrolytic plating method. Further, Patent Document 4 discloses an alloy-based latent heat storage microcapsule (Micro-Encapsulated Phase Change Material: hereinafter abbreviated as MEPCM) that is composed of a core part and a shell covering the core part, and for the shell, the core particles are subjected to a chemical conversion coating treatment and further heat oxidation treatment to form an oxide film. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Laid-Open No. 6-50681 【Patent Document 2】 Japanese Patent Laid-Open No. 10-238979 【Patent Document 3】 Japanese Patent Laid-Open No. 11-23172 【Patent Document 4】 International Publication 2015 / 162929 Brochure [Overview of the Initiative] 【0005】 However, after various studies using MEPCM, it was found that problems such as leakage of the core alloy occurred when the material was processed into molded products. Furthermore, it was found that the mechanical strength of the molded products themselves was insufficient. 【0006】 This invention has been made in view of the problems of conventional MEPCMs, and aims to provide a latent heat storage material composition that is less prone to defects such as metal leakage and cracking when molded into a product, has sufficient mechanical strength, and also has good heat storage and heat dissipation properties. 【0007】 Another object of the present invention is to provide a latent heat storage material molded body and a method for manufacturing the same, which is less prone to defects such as metal leakage and cracking, has sufficient mechanical strength, and also has good heat storage and heat dissipation properties. 【0008】 The inventors of the present invention conducted various studies to achieve the above objectives and arrived at the present invention. As a result, they found that the above problems can be solved by a latent heat storage material composition containing a latent heat storage material and a calcium compound in a predetermined ratio, as well as a latent heat storage material molded article using the same and a method for manufacturing the molded article, thus completing the present invention. 【0009】 In other words, the above objectives can be achieved by the present invention having the following configuration, and the present invention encompasses the following aspects and forms. 【0010】 One aspect of the present invention is, 1. A latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film, and a calcium compound (B) are included. The latent heat storage material composition is characterized in that the ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less. 【0011】 2. In the latent heat storage material composition according to 1. above, it is preferable to contain an inorganic binder and / or an organic binder. 【0012】 3. In the latent heat storage material composition according to 1. or 2. above, it is preferable that the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite. 【0013】 One aspect of the present invention is 4. A latent heat storage material molded body formed by molding the latent heat storage material composition according to any one of 1. to 3. above. 【0014】 5. In the latent heat storage material molded body according to 4. above, it is preferable to contain calcium in an amount of 3% by mass or more and less than 20% by mass in terms of oxide. 【0015】 6. In the latent heat storage material molded body according to 4. or 5. above, it is preferable to have one or more shapes selected from the group consisting of columnar, pellet状, spherical, ring状, plate状, rod状, and honeycomb状. 【0016】 One aspect of the present invention is 7. (1) A latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film and a calcium compound (B) are mixed so that the content (mass) ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less to obtain a latent heat storage material composition. (2) Molding the latent heat storage material composition, and (3) firing at 700 °C or higher. A method for producing a latent heat storage material molded body comprising these steps. 【0017】 8. In the production method according to 7. above, it is further preferable to add and mix an inorganic binder and / or an organic binder. 【0018】 9. In the production method according to 7. or 8. above, it is preferable that the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite. 【0019】 10. In the production method according to any one of 7. to 9. above, it is preferable to mold the latent heat storage material composition into one or more shapes selected from the group consisting of columnar, pellet-like, spherical, ring-like, plate-like, rod-like, and honeycomb-like shapes. 【0020】 11. In the production method according to any one of 7. to 10. above, it is preferable that the latent heat storage material molded body contains calcium in an amount of 3% by mass or more and less than 20% by mass in terms of oxide. 【0021】 12. In the production method according to any one of 7. to 11. above, it is preferable that the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium. 【Mode for Carrying Out the Invention】 【0022】 One embodiment of the present invention includes a latent heat storage material (A) in which core particles containing an Al—Si alloy are coated with an aluminum oxide film, and a calcium compound (B), and the ratio of the content (mass) of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less. By molding the latent heat storage material composition having the above configuration, defects such as metal leakage and cracking are less likely to occur (that is, excellent processing stability), it has sufficient mechanical strength, and a molded body having good heat storage performance and heat dissipation performance can be obtained. 【0023】 Another embodiment of the present invention is a latent heat storage material molded body obtained by molding the above latent heat storage material composition. The latent heat storage material molded body is less likely to have defects such as metal leakage and cracking (that is, excellent processing stability), has sufficient mechanical strength, and further has good heat storage performance and heat dissipation performance. 【0024】 Another embodiment of the present invention is a method for manufacturing a latent heat storage material molded body, comprising: (1) mixing a latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film with a calcium compound (B) to obtain a latent heat storage material composition; (2) molding the latent heat storage material composition; and (3) firing it at 700°C or higher. The latent heat storage material molded body obtained by this manufacturing method is less prone to defects such as metal leakage and cracking (i.e., has excellent processing stability), has sufficient mechanical strength, and further has good heat storage and heat dissipation properties. 【0025】 The present invention will be described in detail below. However, the present invention is not limited to the embodiments described below. In addition, unless otherwise specified in this specification, operations and measurements of physical properties, etc., will be performed under conditions of room temperature (20°C to 25°C) and relative humidity of 40%RH to 50%RH. 【0026】 Furthermore, throughout this specification, singular expressions should be understood to include the concept of their plural form unless otherwise specified. Therefore, singular articles (e.g., "a," "an," "the," etc. in English) should be understood to include the concept of their plural form unless otherwise specified. Also, terms used in this specification should be understood to have the meaning commonly used in the art unless otherwise specified. Therefore, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this invention belongs. In case of any conflict, this specification (including definitions) shall prevail. This invention is not limited to the embodiments described below and can be modified in various ways within the scope of the claims. Also, in this specification, "X~Y" means a range including the numerical values (X and Y) before and after it as the lower and upper limits, and means "X or more and Y or less." Furthermore, concentration "%" represents mass concentration "mass%" unless otherwise specified, and ratios represent mass ratios unless otherwise specified. 【0027】 Furthermore, combinations of two or more of the individual preferred embodiments of the present invention described below are also preferred embodiments of the present invention. 【0028】 [Latent heat storage material composition] The latent heat storage material composition of the present invention comprises a latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film, and a calcium compound (B), wherein the ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less. 【0029】 As described above, the latent heat storage material composition having the above configuration is less prone to defects such as metal leakage and cracking when molded (i.e., has excellent processing stability), and the molded product has sufficient mechanical strength and good heat storage and heat dissipation properties. The mechanism by which the latent heat storage material composition of the present invention exhibits these effects is not clear, but the following is a possible explanation. 【0030】 First, by including a specific latent heat storage material (A) and a calcium compound (B) in predetermined proportions, when the latent heat storage material composition is molded, the calcium compound (B) acts on the aluminum oxide film of the latent heat storage material (A), making it less likely for cracks to occur in the film. This suppresses metal leakage. Furthermore, since the calcium compound (B) promotes adhesion between the latent heat storage materials (A), cracking of the molded body itself is also suppressed, and it is believed that the mechanical strength is further improved. In addition, because metal leakage is less likely to occur, it is believed that the heat storage and heat dissipation properties are sufficiently maintained even after molding. It should be noted that the above mechanism is speculative, and the present invention is not limited in any way to the above mechanism. 【0031】 The latent heat storage material composition and latent heat storage material molded article according to one embodiment preferably contain calcium compound (B) in an amount of 3% to 20% by mass, preferably 5% or more by mass, preferably 8% or more by mass, and preferably 10% or more by mass, on an oxide basis. 【0032】 <Latent heat storage material (A)> The latent heat storage material (A) used in the latent heat storage material composition of the present invention is an alloy-based latent heat storage material in which core particles made of an Al-Si alloy are coated with an aluminum oxide film. 【0033】 In one embodiment of the latent heat storage material composition, the lower limit of the content of the latent heat storage material (A) is preferably 60% by mass or more, more preferably 65% by mass or more, even more preferably 70% by mass or more, and particularly preferably 75% by mass or more, based on the mass of the total solid content of the latent heat storage material composition. The upper limit of the content of the latent heat storage material (A) is preferably 97% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, particularly preferably 85% by mass or less, and most preferably 80% by mass or less, based on the mass of the total solid content of the latent heat storage material composition. In other words, the content of the latent heat storage material (A) in the latent heat storage material composition according to one embodiment is, in terms of solid content, 60% to 97% by mass, 60% to 95% by mass, 60% to 90% by mass, 60% to 85% by mass, 60% to 80% by mass, 65% to 97% by mass, 65% to 95% by mass, 65% to 90% by mass, and 65% to 85% by mass. The content may be less than or equal to % by mass, 65% to 80% by mass, 70% to 97% by mass, 70% to 95% by mass, 70% to 90% by mass, 70% to 85% by mass, 70% to 80% by mass, 75% to 97% by mass, 75% to 95% by mass, 75% to 90% by mass, 75% to 85% by mass, or 75% to 80% by mass. By having the content of latent heat storage material (A) within the above range, the heat storage and heat dissipation properties are further improved while maintaining the strength of the latent heat storage material composition and the molded article of said latent heat storage material composition. 【0034】 The average particle size of the latent heat storage material (A) according to one embodiment is preferably 1 μm or more and 600 μm or less, more preferably 5 μm or more and 250 μm or less, and even more preferably 10 μm or more and 150 μm or less. By having the average particle size of the latent heat storage material (A) within the above range, the mechanical strength and processing stability of the molded article can be further improved. 【0035】 [Core Particles] The Al-Si alloy contained in the core particles of the latent heat storage material (A) may be any alloy consisting of aluminum and silicon. However, the silicon content in the Al-Si alloy is preferably 4% to 40% by mass, more preferably 8% to 30% by mass, even more preferably 10% to 25% by mass, and particularly preferably 12% to 25% by mass. Furthermore, the aluminum content in the Al-Si alloy is preferably 60% to 96% by mass, more preferably 70% to 92% by mass, and even more preferably 75% to 90% by mass. If the silicon and aluminum content in the Al-Si alloy is within the above ranges, the volume expansion rate during the phase change from solid to liquid phase can be suppressed to a low level, thereby increasing the durability as a MEPCM and reducing the likelihood of metal leakage. 【0036】 Furthermore, Al-Si alloys may contain unavoidable impurities in addition to aluminum and silicon. "Unavoidable impurities" refer to substances that are present in the raw materials or inevitably introduced during the manufacturing process. These unavoidable impurities are not inherently desirable, but are acceptable because they are present in trace amounts and do not affect the properties of Al-Si alloys. Examples of unavoidable impurities include titanium (Ti), iron (Fe), and nickel (Ni) in amounts of 0.2 mass% or less (lower limit 0 mass%), and copper (Cu), manganese (Mn), lead (Pb), cadmium (Cd), etc., in amounts of 0.01 mass% or less (lower limit 0 mass%), or 0.005 mass% or less (lower limit 0 mass%). 【0037】 The proportion of Al-Si alloy contained in the core particles is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass, relative to the total mass of the core particles. When the proportion of Al-Si alloy contained in the core particles is within the above range, the function as a latent heat storage material, such as heat storage capacity and heat release capacity, is further improved. 【0038】 Furthermore, Al-Si alloys can be manufactured by previously known methods. 【0039】 In one embodiment of the latent heat storage material (A), the average particle diameter of the core particles is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. Having the particle diameter within this range ensures an appropriate ratio of the shell portion to the core portion responsible for heat storage, thereby preventing a decrease in heat storage density. Furthermore, in one embodiment of the latent heat storage material (A), the average particle diameter of the core particles is preferably 500 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less. As the latent heat storage material is repeatedly used, the core portion melts and solidifies, causing expansion and contraction. However, having the particle diameter within the above range ensures an appropriate ratio of the core to the shell, effectively preventing metal leakage that occurs when the shell cannot withstand stress. In other words, the average particle size of the core particles of the latent heat storage material (A) according to one embodiment is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 200 μm or less, and even more preferably 10 μm or more and 100 μm or less. 【0040】 Here, the average particle size of the core particles is the value measured by the method described in the Examples. Furthermore, the cumulative 90% volume diameter of the core particles of the latent heat storage material (A) is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 80 μm or less, and even more preferably 30 μm or more and 70 μm or less. 【0041】 [Aluminum oxide coating] The aluminum oxide coating is not particularly limited, but may be a single layer or comprise multiple layers. While not limited, it is preferable, for example, to include α-Al2O3 as a component. The components constituting the aluminum oxide coating are not limited to aluminum oxide alone, but may also include other elements and / or unavoidable impurities. 【0042】 Furthermore, while the thickness of the aluminum oxide film is not particularly limited, it is preferably 0.1 μm to 10 μm, and more preferably 0.5 μm to 5 μm. By having the aluminum oxide film thickness within the above range, the aluminum oxide film can sufficiently cover the surface of the Al-Si alloy core particles while maintaining heat storage and heat dissipation properties, thus reducing the likelihood of metal leakage. The thickness of the aluminum oxide film can be determined by subtracting the average particle diameter of the core particles from the average particle diameter of the latent heat storage material, and then dividing the result by 2. 【0043】 [Method for manufacturing latent heat storage material (A)] The method for producing the latent heat storage material (A) is not particularly limited, and known methods can be used. However, it is preferable to use aluminum hydroxide with a boehmite crystal structure as the raw material for forming the aluminum oxide film on the Al-Si alloy core particles. By using aluminum hydroxide with a boehmite (AlOOH) crystal structure, a dense oxide film can be formed. 【0044】 The aluminum oxide film can be formed by immersing core particles made of an Al-Si alloy in an aqueous solution containing aluminum hydroxide having a boehmite crystal structure. The aluminum hydroxide content in the aqueous solution is preferably 0.5 to 25 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of core particles. By having an aluminum hydroxide content in the aqueous solution within the above range, a sufficient oxide film can be formed on the surface of the core particles. 【0045】 It is preferable to add a small amount of ammonia or the like to the aqueous solution described above. The aluminum oxide film obtained tends to be of better quality as the pH value increases. The pH of the aqueous solution is preferably 6.0 or higher and less than 11.0 at room temperature, more preferably 7.0 to 10.5, and even more preferably 8.5 to 10.0. 【0046】 The reaction temperature for forming the aluminum oxide film is preferably 60°C to 100°C, more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher. The upper limit of the temperature is the boiling point of the aqueous solution, which is 100°C under normal pressure. The reaction time is preferably 0.25 to 24 hours, and more preferably 0.5 to 5 hours. 【0047】 In one embodiment of the latent heat storage material (A), it is preferable to perform a thermal oxidation treatment after forming an aluminum oxide film on the core particles. This further oxidizes the aluminum oxide film formed on the surface of the core particles, allowing it to be converted into crystalline Al2O3 MEPCM. 【0048】 The temperature at which the thermal oxidation treatment is performed is preferably higher than the melting point of the Al-Si alloy that forms the core. In the case of an alloy with a silicon content of 4 to 40 wt%, the melting point is 580°C, and it is preferable to heat it to a temperature higher than that (for example, 700°C or higher). More preferably, it is preferable to treat it at 800°C or higher, and even more preferably at 900°C or higher. This is because the aluminum oxide film formed by the heat treatment takes on a γ-Al2O3 crystal structure at relatively low temperatures below 800°C, while a film with a chemically stable α-Al2O3 crystal structure can be obtained at relatively high temperatures above 880°C. The upper limit is not particularly limited, but it is preferably 1200°C or lower. The heat treatment time is preferably 0.5 to 12 hours, and more preferably 2 to 5 hours. By performing the above thermal oxidation treatment, the aluminum oxide film is more sufficiently oxidized, and a highly stable MEPCM can be obtained. 【0049】 In one embodiment, the thermal oxidation treatment of the heat-storing latent heat material (A) can be performed simultaneously with the firing process of the molded body (step 3), which will be described later. Alternatively, the thermal oxidation treatment of the heat-storing latent heat material (A) and the firing process of the molded body (step 3) can be performed separately. Performing the thermal oxidation treatment and firing simultaneously simplifies the manufacturing process, which is expected to improve production efficiency and reduce production costs. 【0050】 <Calcium compounds (B)> The latent heat storage material composition of the present invention contains a calcium compound (B). Furthermore, in the latent heat storage material composition, the calcium compound (B) is contained in a proportion of 1% by mass or more and 40% by mass or less relative to the latent heat storage material (A) (content of calcium compound (B) / content of latent heat storage material (A) × 100 (mass%)). 【0051】 Furthermore, in the latent heat storage material composition, it is preferable that calcium be present in an oxide equivalent of 3% to less than 20% by mass, more preferably 5% or more by mass, even more preferably 8% or more by mass, and particularly preferably 10% or more by mass. The upper limit is more preferably 18.5% or less by mass, and even more preferably 15% or less by mass. The calcium content (oxide equivalent) in the latent heat storage material composition can be calculated by analyzing the concentration of each element using an ICP emission spectrometer and then converting it to oxide equivalent. 【0052】 Calcium compounds are materials containing calcium, and the concept includes not only single compounds but also minerals in which the compound is the main component (for example, wollastonite, which is mainly composed of calcium silicate). Here, "main component" means that the compound is present in an amount of 60% or more, 70% or more, 80% or more, or 90% or more of the total amount. 【0053】 Examples of calcium compounds (B) include inorganic calcium compounds such as calcium oxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium carbide, calcium carbonate, calcium nitrate, calcium sulfate, calcium sulfite, calcium silicate, calcium phosphate, calcium hydroxide phosphate, calcium pyrophosphate, calcium hypochlorite, calcium chlorate, calcium chromate, calcium tungstate, calcium molybdate, calcium magnesium carbonate (double salt of calcium carbonate and magnesium carbonate), and hydroxyapatite; organic calcium compounds such as calcium acetate, calcium stearate, and calcium lactate; and calcium minerals such as limestone, gypsum, wollastonite, scheelite, anorthite, dolomite, hydroxyapatite, calcite, and fluorite. Two or more of these may be used in combination. In particular, from the viewpoint of improving the processing stability of the latent heat storage material composition, calcium compound (B) is preferably calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, or wollastonite, and more preferably one or more selected from the group consisting of calcium hydroxide, calcium carbonate, and wollastonite. 【0054】 That is, calcium compound (B) may be one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium carbide, calcium carbonate, calcium nitrate, calcium sulfate, calcium sulfite, calcium silicate, calcium phosphate, calcium hydroxide phosphate, calcium pyrophosphate, calcium hypochlorite, calcium chlorate, calcium chromate, calcium tungstate, calcium molybdate, calcium magnesium carbonate (double salt of calcium carbonate and magnesium carbonate), hydroxyapatite, calcium acetate, calcium stearate, calcium lactate, limestone, gypsum, wollastonite, scheelite, anorthite, dolomite, hydroxyapatite, calcite, and fluorite. Alternatively, calcium compound (B) may be one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite, or one or more selected from the group consisting of calcium hydroxide, calcium carbonate, and wollastonite, or one or more selected from the group consisting of calcium carbonate and wollastonite. In this specification, calcium silicate includes calcium silicate having various chemical compositions, such as CaSiO3, Ca2SiO4, Ca3SiO5, and Ca3Si2O7. 【0055】 In the latent heat storage material composition, the ratio of calcium compound (B) content to latent heat storage material (A) is 1% by mass or more and 40% by mass or less, but the lower limit of this ratio is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 10% by mass or more, particularly preferably 15% by mass or more, and most preferably 20% by mass or more. The upper limit of this ratio is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 28% by mass or less. That is, the ratios are 1% by mass or more and 35% by mass or less, 1% by mass or more and 30% by mass or less, 1% by mass or more and 28% by mass or less, 5% by mass or more and 40% by mass or less, 5% by mass or more and 35% by mass or less, 5% by mass or more and 30% by mass or less, 5% by mass or more and 28% by mass or less, 7% by mass or more and 40% by mass or less, 7% by mass or more and 35% by mass or less, 7% by mass or more and 30% by mass or less, 7% by mass or more and 28% by mass or less, and 10% by mass or more and 40% by mass or less. The following ranges may also be used: 10% by mass or more and 35% by mass or less, 10% by mass or more and 30% by mass or less, 10% by mass or more and 28% by mass or less, 15% by mass or more and 40% by mass or less, 15% by mass or more and 35% by mass or less, 15% by mass or more and 30% by mass or less, 15% by mass or more and 28% by mass or less, 20% by mass or more and 40% by mass or less, 20% by mass or more and 35% by mass or less, 20% by mass or more and 30% by mass or less, or 20% by mass or more and 28% by mass or less. By having the ratio of calcium compound (B) content to latent heat storage material (A) within the above ranges, the heat storage and heat dissipation properties of the latent heat storage material composition and the molded article of the latent heat storage material composition can be maintained in good condition, while the mechanical strength and processing stability of the molded article can be further improved. 【0056】 <Binder> In one embodiment, the latent heat storage material composition preferably contains an inorganic binder and / or an organic binder. Including these binders further improves the processing stability when the latent heat storage material composition is molded, and also improves the mechanical strength of the molded product itself. 【0057】 The inorganic binder is not particularly limited, but examples include zirconia, silica, alumina, and titania. Among these inorganic binders, silica and / or alumina are preferred, and it is more preferable that silica is included. Examples of organic binders include celluloses such as methylcellulose, carboxymethylcellulose, hydroxyalkylmethylcellulose, sodium carboxymethylcellulose, and ethylcellulose; alcohols such as polyvinyl alcohol; and lignin sulfonates. Of these, one type of binder may be used, or two or more types may be used in combination. However, in this specification, the binder does not include the calcium compound (B) mentioned above. 【0058】 As a binder, it is preferable to use at least cellulose, and more preferably methylcellulose, because this improves the processing stability during molding and also improves the mechanical strength of the molded product itself. 【0059】 In one embodiment of the latent heat storage material composition, the binder content is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on the mass of the total solid content of the latent heat storage material composition. Furthermore, the lower limit of the binder content is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.4% by mass or more, particularly preferably 0.5% by mass or more, and most preferably 1% by mass or more, based on the solid content. In other words, the binder content may be 0.1% to 15% by mass, 0.1% to 10% by mass, 0.1% to 5% by mass, 0.2% to 15% by mass, 0.2% to 10% by mass, 0.2% to 5% by mass, 0.4% to 15% by mass, 0.4% to 10% by mass, 0.4% to 5% by mass, 0.4% to 10% by mass, 0.4% to 5% by mass, 0.5% to 15% by mass, 0.5% to 10% by mass, 0.5% to 5% by mass, 1% to 15% by mass, 1% to 10% by mass, or 1% to 5% by mass, based on solid content relative to the total solid content of the latent heat storage material composition. By keeping the binder content within the above range, the heat storage and heat dissipation properties of the latent heat storage material composition and the molded product of the latent heat storage material composition are well maintained, while the processing stability when molding the latent heat storage material composition is significantly improved, and the mechanical strength of the molded product can also be further improved. When two or more types of binders are used, the above binder content is the sum of the content of each binder. 【0060】 <Other ingredients> The composition of the present invention may also contain other components. Examples of other components include oxides such as magnesia (magnesium oxide) and ceria (cerium(IV) oxide), glass frit, and sintering aids such as silicon carbide. 【0061】 [Latent heat storage material molded body] One embodiment of the present invention is a latent heat storage material molded body that uses the latent heat storage material composition described above. That is, the latent heat storage material molded body is formed by molding the latent heat storage material composition. As a result, the latent heat storage material molded body is less prone to defects such as metal leakage and cracking, has sufficient mechanical strength, and also has good heat storage and heat dissipation properties. 【0062】 In one embodiment, the latent heat storage material molded article preferably contains 3% by mass or more of calcium on an oxide basis, more preferably 5% by mass or more, even more preferably 8% by mass or more, and particularly preferably 10% by mass or more. Furthermore, the upper limit of calcium contained in the latent heat storage material molded article according to one embodiment is preferably less than 20% by mass on an oxide basis. That is, in one embodiment, the latent heat storage material molded article preferably contains 3% by mass or more and less than 20% by mass of calcium on an oxide basis, more preferably 5% by mass or more and less than 20% by mass, even more preferably 8% by mass or more and less than 20% by mass, and particularly preferably 10% by mass or more and less than 20% by mass. By having the calcium content (on an oxide basis) within the above range, the mechanical strength of the latent heat storage material molded article becomes more sufficient. 【0063】 The calcium content (in oxide equivalent) in the latent heat storage material molded body can be calculated by analyzing the concentration of each element using an ICP emission spectrometer and then converting it to oxide equivalent. More specifically, the method described in the examples can be used. 【0064】 The latent heat storage material molded body according to one embodiment is not particularly limited, but it is preferable to have one or more shapes selected from the group consisting of cylindrical, pellet-shaped, spherical, ring-shaped, plate-shaped, rod-shaped, and honeycomb-shaped. Having such shapes makes the latent heat storage material molded body easier to handle industrially. 【0065】 The size of the latent heat storage material molded body according to one embodiment is not particularly limited. For example, when the latent heat storage material molded body is cut in a plane so as to maximize the cross-sectional area, if the shape of the cross-section (shape of the outer perimeter) is not a polygon, the longest side of the rectangle inscribed in the cross-section may be 0.1 mm or more, 0.5 mm or more, 1 mm or more, 1.5 mm or more, 2 mm or more, or 5 mm or more. There is no particular upper limit to the longest side, but it may be 50 cm or less, 25 cm or less, 15 cm or less, 10 cm or less, 5 cm or less, or 1 cm or less. In other words, the major axis is 0.1 mm to 50 cm, 0.1 mm to 25 cm, 0.1 mm to 15 cm, 0.1 mm to 10 cm, 0.1 mm to 5 cm, 0.1 mm to 1 cm, 0.5 mm to 50 cm, 0.5 mm to 25 cm. Bottom, 0.5 mm to 15 cm, 0.5 mm to 10 cm, 0.5 mm to 5 cm, 0.5 mm to 1 cm, 1 mm to 50 cm, 1 mm to 25 cm, 1 mm to 15 cm, 1 mm to 10 cm, 1 mm to 5 cm, 1 mm The polygons may be 1 cm or less above, 1.5 mm to 50 cm, 1.5 mm to 25 cm, 1.5 mm to 15 cm, 1.5 mm to 10 cm, 1.5 mm to 5 cm, 1.5 mm to 1 cm, 2 mm to 50 cm, 2 mm to 25 cm, 2 mm to 15 cm, 2 mm to 10 cm, 2 mm to 5 cm, 2 mm to 1 cm, 5 mm to 50 cm, 5 mm to 25 cm, 5 mm to 15 cm, 5 mm to 10 cm, 5 mm to 5 cm, or 5 mm to 1 cm. Here, shapes other than polygons include circles and ellipses. 【0066】 Furthermore, when a latent heat storage material molded body is cut in a plane such that the cutting area is maximized, if the shape of the plane of the cut surface (shape of the outer perimeter) is polygonal, the major axis (diameter in the case of a circle) of the ellipse (including a circle) inscribed in the polygon may be 0.5 mm or more, 1 mm or more, 2 mm or more, 5 mm or more, 1 cm or more, or 10 cm or more. There is no particular upper limit to the major axis, but it may be 200 cm or less, 150 cm or less, 100 cm or less, 50 cm or less, or 25 cm or less. In other words, the longest diameter is 0.5 mm to 200 cm, 0.5 mm to 150 cm, 0.5 mm to 100 cm, 0.5 mm to 50 cm, 0.5 mm to 25 cm, 1 mm to 200 cm, 1 mm to 150 cm, 1 mm to 100 cm, 1 mm to 50 cm, 1 mm to 25 cm, 2 mm to 200 cm, 2 mm to 150 cm, 2 mm to 100 cm, 2 mm to 50 cm, 2 mm to 25 The diameter may be less than or equal to cm, 5 mm to 200 cm, 5 mm to 150 cm, 5 mm to 100 cm, 5 mm to 50 cm, 5 mm to 25 cm, 1 cm to 200 cm, 1 cm to 150 cm, 1 cm to 100 cm, 1 cm to 50 cm, 1 cm to 25 cm, 10 cm to 200 cm, 10 cm to 150 cm, 10 cm to 100 cm, 10 cm to 50 cm, or 10 cm to 25 cm. The fact that the major axis is within this range makes the filling process as a heat storage material easier. Here, polygons include triangles, quadrilaterals, pentagons, hexagons, etc. 【0067】 When the shape of the latent heat storage material molded body according to one embodiment is cylindrical, the lower limit of the diameter of the base is preferably 0.5 mm or more, more preferably 1 mm or more, even more preferably 2 mm or more, particularly preferably 3 mm or more, and particularly preferably 4 mm or more. The upper limit of the diameter of the base is preferably 20 mm or less, more preferably 15 mm or less, even more preferably 10 mm or less, and particularly preferably 8 mm or less. In other words, when the shape of the latent heat storage material molded body is cylindrical, the diameter of the bottom surface may be 1 mm or more and 20 mm or less, 1 mm or more and 15 mm or less, 1 mm or more and 10 mm or less, 1 mm or more and 8 mm or less, 2 mm or more and 20 mm or less, 2 mm or more and 15 mm or less, 2 mm or more and 10 mm or less, 2 mm or more and 8 mm or less, 3 mm or more and 15 mm or less, 3 mm or more and 10 mm or less, 3 mm or more and 8 mm or less, 4 mm or more and 20 mm or less, 4 mm or more and 15 mm or less, 4 mm or more and 10 mm or less, or 4 mm or more and 8 mm or less. Furthermore, when the shape of the latent heat storage material molded body according to one embodiment is cylindrical, the height of the cylinder is preferably 0.5 mm or more, more preferably 1 mm or more, even more preferably 2 mm or more, particularly preferably 3 mm or more, and particularly preferably 4 mm or more. Furthermore, the upper limit of the height of the cylinder is preferably 20 mm or less, more preferably 15 mm or less, even more preferably 10 mm or less, and particularly preferably 8 mm or less. That is, when the shape of the latent heat storage material molded body is cylindrical, the height of the cylinder may be 1 mm to 20 mm, 1 mm to 15 mm, 1 mm to 10 mm, 1 mm to 8 mm, 2 mm to 20 mm, 2 mm to 15 mm, 2 mm to 10 mm, 2 mm to 8 mm, 3 mm to 20 mm, 3 mm to 15 mm, 3 mm to 10 mm, 3 mm to 8 mm, 4 mm to 20 mm, 4 mm to 15 mm, 4 mm to 10 mm, or 4 mm to 8 mm. When the shape of the lower latent heat storage material molded body is cylindrical, the diameter and height of the bottom surface are within the above range, which facilitates the filling work as a heat storage material. 【0068】 Furthermore, the range of the base diameter and the range of the cylinder height described above can be combined as appropriate. For example, the cylinder height may be 1 mm to 20 mm when the base diameter is 1 mm or more and 20 mm or less; the cylinder height may be 2 mm to 15 mm when the base diameter is 2 mm or more and 15 mm or less; the cylinder height may be 3 mm to 10 mm when the base diameter is 3 mm or more and 10 mm or less; and the cylinder height may be 4 mm to 8 mm when the base diameter is 4 mm or more and 8 mm or less. 【0069】 In one embodiment, when the shape of the latent heat storage material molded body is honeycomb-shaped, the external shape of the latent heat storage material molded body is a substantially rectangular prism or a substantially cylindrical shape having a first end face and a second end face, and further having a plurality of cells that penetrate from the first end face to the second end face. 【0070】 The shape of the first and second end faces is not particularly limited and may be a polygon such as a triangle, quadrilateral, pentagon, or hexagon, or it may be an ellipse or a circle. Furthermore, the area of the first and second end faces is not particularly limited, but 100 cm² is not particularly limited. 2 More than 1000cm 2 Preferably, it is 150cm 2 More than 750cm 2 It is more preferable that the following conditions apply: 200 cm 2 More than 500cm 2 The following is more preferable. Furthermore, when the shape of the latent heat storage material molded body is honeycomb, the height of the prism or cylinder is preferably 10 cm or more and 200 cm or less, more preferably 50 cm or more and 150 cm or less, and more preferably 75 cm or more and 125 cm or less. Having the above shape of the latent heat storage material molded body makes it easier to handle as a heat storage material. 【0071】 Furthermore, the shape of the cell is not particularly limited, but the shape of the cross-section perpendicular to the direction in which the cell penetrates may be a triangle, square, pentagon, hexagon, octagon, circle, or ellipse. The area of the cross-section perpendicular to the direction in which the cell penetrates is not particularly limited, but 0.05 cm² is not particularly limited. 2 More than 25cm2 It is preferably the following, 0.1 cm 2 or more and 15 cm or less 2 More preferably, it is the following, 0.25 cm 2 or more and 10 cm or less 2 Even more preferably, it is the following, 0.5 cm 2 or more and 5 cm or less 2 Particularly preferably, it is the following. When the cross-section of the cell is within the above range, the efficiency of heat storage and heat release is improved, and the usefulness as a latent heat storage material is improved. 【0072】 [Method for manufacturing a molded body of a latent heat storage material] The method for manufacturing a molded body of a latent heat storage material of the present invention is (1) A latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film and a calcium compound (B) are mixed so that the content (mass) ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less to obtain a latent heat storage material composition (Step 1), (2) The latent heat storage material composition is molded (Step 2), and (3) fired at 700°C or higher (Step 3). The method includes these steps. 【0073】 〈Regarding Step 1〉 This step is a step of mixing a latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film and a calcium compound (B) so that the content (mass) ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less to obtain a latent heat storage material composition. 【0074】 The latent heat storage material (A) and calcium compound (B) used in the process are similarly adopted in the preferred forms described in the sections for "Latent Heat Storage Material (A)" and "Calcium Compound (B)," respectively. In particular, from the viewpoint of ease of mixing and improvement of processing stability when the latent heat storage material composition is molded, it is preferable that the calcium compound (B) used in the process be one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite. 【0075】 In this process, the latent heat storage material (A) and the calcium compound (B) are mixed such that the ratio of calcium compound (B) to latent heat storage material (A) in the latent heat storage material composition is 1% by mass or more and 40% by mass or less. The preferred range for this ratio is the same as the preferred form described in the section on calcium compound (B) above. By keeping this ratio within the above range, it becomes easier to obtain a latent heat storage material molded article that maintains good heat storage and heat dissipation properties while also having good mechanical strength and processing stability. 【0076】 In this process, the mixing method is not particularly limited as long as the components such as the latent heat storage material (A) and the calcium compound (B) are uniformly mixed. However, it is preferable to use a so-called wet mixing method, in which the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium. Mixing with a dispersion medium allows for more uniform mixing of the latent heat storage material (A) and the calcium compound (B), etc. 【0077】 The dispersion medium used in wet mixing is not particularly limited, but examples include water, organic solvents, and mixtures thereof, and one or more of these may be used. Examples of organic solvents include alcohols such as methanol, ethanol, propanol, and isopropanol; glycols such as ethylene glycol and propylene glycol; ketones such as acetone, 2-butanone, and 4-methyl-2-pentanone; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, and propylene glycol methyl ether acetate; dimethyl sulfoxide; dimethylformamide; dimethylacetamide; and aromatic hydrocarbons such as benzene, toluene, and xylene. In particular, from the viewpoint of the effects of the present invention, the dispersion medium is preferably water and / or a hydrophilic organic solvent (lower alcohols (e.g., C1-C3) such as methyl alcohol and isopropyl alcohol; ketones such as acetone; amides such as N,N-dimethylformamide; sulfoxides such as dimethyl sulfoxide; glycols such as ethylene glycol; etc.), and more preferably water and / or a lower alcohol (e.g., C1-C3). The dispersion medium may also be one that is used as a dispersion medium such as an inorganic binder. 【0078】 The dispersion medium mixed with the latent heat storage material (A) and the calcium compound (B) is preferably 10% to 150% by mass, more preferably 15% to 100% by mass, and even more preferably 20% to 90% by mass, based on the total mass (solid content) of the latent heat storage material (A) and the calcium compound (B). By having the amount of dispersion medium within this range, the latent heat storage material (A) and the calcium compound (B), etc., can be mixed more thoroughly and uniformly. 【0079】 Furthermore, after mixing the latent heat storage material (A) and the calcium compound (B) with the dispersion medium, it is preferable to dry the dispersion medium used in the mixing so that its amount is below a certain level. Therefore, it is preferable that the dispersion medium is volatile. 【0080】 In this process, it is preferable to add and mix an inorganic binder and / or an organic binder. The types of inorganic and organic binders, and the binder content in the latent heat storage material composition, are similar to those described in the "Binder" section above. Adding a binder makes it easier to mold the latent heat storage material composition, reduces cracking of the molded product, and further improves its mechanical strength. 【0081】 In this process, it is preferable to mix the latent heat storage material (A) and the calcium compound (B), and then add and mix in an inorganic binder and / or an organic binder. Furthermore, if the latent heat storage material (A) and the calcium compound (B) are mixed with a dispersion medium, it is preferable to thoroughly dry the dispersion medium before adding and mixing in the inorganic binder and / or the organic binder. By doing so, each component contained in the latent heat storage material composition can be mixed more uniformly, more effectively suppressing cracks in the molded product and further improving its mechanical strength. 【0082】 <Regarding steps 2 and 3> A method for manufacturing a latent heat storage material molded article according to one embodiment of the present invention includes molding the latent heat storage material composition obtained in step (1) above (step 2) and firing it at 700°C or higher (step 3). 【0083】 In step 2, it is preferable to mold the latent heat storage material composition into one or more shapes selected from the group consisting of cylindrical, pellet-shaped, spherical, ring-shaped, plate-shaped, rod-shaped, and honeycomb-shaped, and more preferably into a cylindrical shape. Having this shape makes the molded latent heat storage material body easier to handle industrially. The size of the molded latent heat storage material body is the same as the preferred form described in the section on molded latent heat storage material. 【0084】 In step 2, the method for molding the latent heat storage material composition into a desired shape is not particularly limited, but examples include uniaxial compression molding, isotropic compression molding, injection molding, extrusion molding, rolling granulation, and casting, with extrusion molding being preferred. 【0085】 Furthermore, in step 2 according to one embodiment, a small amount of solvent may be added to the latent heat storage material composition, and after mixing the latent heat storage material composition and the solvent, it may be molded into a desired shape. The desired solvent is similar to the "dispersion medium" described in the section on step 1. By molding after mixing the latent heat storage material composition and the solvent, it becomes easier to maintain the shape after molding, thus facilitating the production of the latent heat storage material molded body. A preferred solvent is, for example, water. 【0086】 The firing temperature in step 3 may be 700°C or higher, but is preferably 800°C or higher, and more preferably 850°C or higher. The upper limit of the firing temperature is not particularly limited, but is preferably less than 1200°C, more preferably 1100°C or lower, and even more preferably 1000°C or lower. That is, the firing temperature may be 700°C or higher and less than 1200°C, 700°C or higher and 1100°C or lower, 700°C or higher and 1000°C or lower, 800°C or higher and less than 1200°C, 800°C or higher and 1100°C or lower, 800°C or higher and 1000°C or lower, 850°C or higher and less than 1200°C, 850°C or higher and 1100°C or lower, and 850°C or higher and 1000°C or lower. By having the firing temperature within the above range, the strength of the molded body becomes more sufficient, and metal leakage from the latent heat storage material (A) becomes less likely. 【0087】 In one embodiment of the manufacturing method, when the latent heat storage material composition and the dispersion are mixed in step 2, a step of drying the molded latent heat storage material composition (precursor of the latent heat storage material molded body) may be included between step 2 and step 3. By including this step, the occurrence of defects such as cracks in the manufactured latent heat storage material molded body can be effectively suppressed. 【0088】 Furthermore, in the manufacturing method according to one embodiment, a degreasing step may be included before the firing in step 3, in which the molded latent heat storage material composition is heated to a predetermined temperature. Here, the predetermined temperature in the degreasing step is not particularly limited, but it is preferably 250°C or more and 600°C or less. In addition, it is preferable to maintain the predetermined temperature for 1 hour or more and 3 hours or less in the degreasing step. By including a degreasing step, organic binders and the like contained in the latent heat storage material composition molded in step 2 can be removed, and the occurrence of defects such as cracks in the latent heat storage material molded body can be effectively suppressed. 【0089】 A latent heat storage material molded article produced by the manufacturing method according to one embodiment may contain 3% to less than 20% by mass of calcium in terms of oxide. Furthermore, the preferred range for the amount of calcium contained in the latent heat storage material molded article is similar to the preferred form described in the section on latent heat storage material molded articles. Having the calcium content (in terms of oxide) within these ranges results in more sufficient mechanical strength for the latent heat storage material molded article. 【0090】 Furthermore, in the method for manufacturing a latent heat storage material molded body according to one embodiment of the present invention, the thermal oxidation treatment of the latent heat storage material (A) and the firing in step 3 can be performed simultaneously. Alternatively, the thermal oxidation treatment of the latent heat storage material (A) and the firing of the molded body may be performed separately. By performing the thermal oxidation treatment and the firing in step 3 simultaneously, the manufacturing process can be simplified, and improvements in production efficiency and reductions in production costs can be expected. [Examples] 【0091】 The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "percent mass". Unless otherwise specified, the operations were carried out at room temperature (25°C). 【0092】 In this embodiment, the measurement of the average particle size and the compositional analysis of the molded article were carried out according to the following methods. 【0093】 <Measurement of average particle size> [Average particle diameter of core particles] Measurements were performed using a HORIBA LA-950V2 laser diffraction particle size analyzer. Specifically, an Al-Si alloy was dispersed in an aqueous solution containing 0.2 wt% sodium pyrophosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and the particle size was measured using the analyzer. The cumulative 50% volume diameter was used as the average particle size. 【0094】 [Average particle size of latent heat storage material (A-1)] Measurements were performed using a HORIBA LA-950V2 laser diffraction particle size analyzer. Specifically, a latent heat storage material (A-1) was dispersed in an aqueous solution containing 0.2 wt% sodium pyrophosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and the particle size was measured using the analyzer. The cumulative 50% volume diameter was used as the average particle size. 【0095】 <Compositional analysis of molded body> The compositional analysis of the molded body was performed using a Thermo Fisher Scientific iCAP6000 SERIES ICP emission spectrometer (hereinafter referred to as ICP). After analyzing the concentration of each element using ICP, the oxide equivalent was calculated. 【0096】 The latent heat storage material compositions for each example and each comparative example were prepared according to the following procedure. 【0097】 [Preparation of Al-Si alloy] Core particles were prepared from an Al-Si alloy (Al-12wt%Si) with a mass ratio of 88% Al and 12% Si. The average particle diameter of these core particles was 31.9 μm, and the cumulative 90% volume diameter was 48.4 μm. 【0098】 [Preparation of latent heat storage material (A-1)] 300g of water was placed in a 1L flask. The mixture was heated in an oil bath while stirring at 150rpm with a stirring blade. After measuring the water temperature and reaching 100°C, 1g of aluminum hydroxide (manufactured by Daimei Chemical Industry Co., Ltd.), whose crystals consist of boehmite, was added and dispersed. Subsequently, 1M ammonia water was added, and the pH of the dispersion was adjusted to be in the range of 9.0 to 9.5 when measured at room temperature. 10g of Al-Si alloy was added to the dispersion after pH adjustment. After addition, the mixture was stirred at 100°C for 2 hours while adjusting the pH, and then cooled. After cooling, excess aluminum hydroxide was removed by decantation, followed by suction filtration, drying, and obtaining a powdered latent heat storage material (A-1). The average particle size of the obtained latent heat storage material (A-1) was 38.8 μm. 【0099】 [Manufacturing of latent heat storage material compositions] <Example 1> Wollastonite was used as the calcium compound (B). Specifically, 4.0 g of the latent heat storage material (A-1) from Synthesis Example 1 and 1.0 g of wollastonite (manufactured by Kinsei Matec, trade name: SH-1250) were weighed into an evaporating dish, and 3.1 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (trade name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical molded precursors. After drying these precursors at 60°C overnight (about 12 hours), firing was performed to obtain cylindrical latent heat storage material molded bodies with a latent heat storage material:oxide ratio of 81:19 mass% and a shape of Φ5 mm × H5 mm. 【0100】 Here, the precursor of the molded body was calcined using an HPM-1G type gas-purged muffle furnace manufactured by AS ONE Corporation. Specifically, a ceramic crucible containing a cylindrical molded body was placed in the muffle furnace, and calcination was performed under the following conditions: air flow rate of 1.0 L / min, heating rate of 5°C / min, calcination conditions of 1000°C for 1 hour to obtain a latent heat storage material molded body. When the temperature reached 530°C, degreasing was performed by maintaining that temperature (530°C) for 2 hours to remove the organic binder. 【0101】 Furthermore, a compositional analysis of the obtained latent heat storage material molded body was performed using ICP, and the calcium concentration was found to be 10.1% by mass (on an oxide basis). 【0102】 <Example 2> As calcium compound (B), instead of the wollastonite used in Example 1, Milcon, a mixture of calcium carbonate (calcium compound (B)) and sepiolite, was used to obtain a latent heat storage material molded body. Here, the calcium carbonate content of calcium compound (B) in Milcon is approximately 15.2% by mass. 【0103】 Specifically, 3.5 g of latent heat storage material (A-1) and 1.5 g of Milcon (manufactured by Showa KDE Co., Ltd., trade name: MS-2), a mixture of calcium carbonate and sepiolite, were weighed into an evaporating dish, and 3.9 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (trade name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical molded body precursors. After drying these precursors at 60°C overnight (about 12 hours), firing was performed under the same conditions as in Example 1 to obtain a cylindrical latent heat storage material molded body with a latent heat storage material:oxide ratio of 76:24 mass% and a shape of Φ5 mm × H5 mm. Furthermore, a compositional analysis of the obtained latent heat storage material molded body was performed using ICP, and the calcium concentration was found to be 5.1% by mass (on an oxide basis). 【0104】 <Example 3> As calcium compound (B), calcium hydroxide was used instead of wollastonite, which was used in Example 1, to obtain a latent heat storage material molded body. 【0105】 Specifically, 4.0 g of latent heat storage material (A-1) and 1.0 g of calcium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were weighed into an evaporating dish, and 2.6 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (product name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical molded body precursors. After drying the precursors at 60°C overnight (about 12 hours), firing was performed under the same conditions as in Example 1 to obtain a cylindrical latent heat storage material molded body with a latent heat storage material:oxide ratio of 84:16 by mass and a shape of Φ5 mm × H5 mm. Furthermore, a compositional analysis of the obtained latent heat storage material molded body was performed using ICP, and the calcium concentration was found to be 18.2% by mass (on an oxide basis). 【0106】 <Example 4> As the calcium compound (B), calcium carbonate was used instead of the wollastonite used in Example 1 to obtain a latent heat storage material molded body. 【0107】 Specifically, 4.0 g of latent heat storage material (A-1) and 1.0 g of calcium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were weighed and placed in a mortar, and 2.3 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (product name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical molded body precursors. After drying these precursors at 60°C overnight (about 12 hours), firing was performed under the same conditions as in Example 1 to obtain a cylindrical latent heat storage material molded body with a latent heat storage material:oxide ratio of 88:12 by mass and a shape of Φ5 mm × H5 mm. Furthermore, a compositional analysis of the obtained latent heat storage material molded body was performed using ICP, and the calcium concentration was found to be 13.6% by mass (on an oxide basis). 【0108】 <Example 5> As the calcium compound (B), calcium carbonate was used instead of the wollastonite used in Example 1, and silica derived from silica sol was used as an additional additive to obtain a latent heat storage material molded body. 【0109】 Specifically, 4.0 g of latent heat storage material (A-1), 0.8 g of calcium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1.2 g of silica sol (manufactured by Nissan Chemical Corporation, solid content concentration: 20.3% by mass, trade name: Snowtex® N), and 0.1 g of methylcellulose (trade name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay mold, which was then placed in a metal mold and extruded to form a cylindrical molded body precursor. After drying the precursor at 60°C overnight (approximately 12 hours), firing was performed under the same conditions as in Example 1 to obtain a cylindrical latent heat storage material molded body with a latent heat storage material:oxide ratio of 86:14% by mass and a diameter of Φ5 mm × H5 mm. Furthermore, a compositional analysis of the obtained latent heat storage material molded body using ICP revealed that the calcium concentration was 9.0% by mass (on an oxide basis). 【0110】 <Example 6> As in Example 1, wollastonite was used as the calcium compound (B), and silica derived from silica sol and aluminum oxide were used as other additives to obtain a latent heat storage material molded body. 【0111】 Specifically, 40.0 g of latent heat storage material (A-1), 3.5 g of wollastonite (manufactured by Kinsei Matec Co., Ltd.), 19.7 g of silica sol (manufactured by Nissan Chemical Corporation, solid content concentration: 20.3% by mass, trade name: Snowtex® N), 2.5 g of alumina (trade name: AS-50, manufactured by Resonaq Corporation, average particle size: 9.8 μm), and 0.2 g of methylcellulose (trade name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain a latent heat storage material composition. Subsequently, water was added to the latent heat storage material composition to prepare a clay mold, and the clay mold was placed in a metal mold and extruded to form 10 cylindrical precursor molds. The precursor was dried at 60°C overnight (approximately 12 hours), and then calcined under the same conditions as in Example 1 to obtain a cylindrical latent heat storage material molded body with a latent heat storage material:oxide ratio of 80:20 mass%, and dimensions of Φ6.7 mm × H6.7 mm. Compositional analysis of the obtained latent heat storage material molded body using ICP revealed that the calcium concentration was 3.7 mass% (on an oxide basis). 【0112】 <Comparative Example 1> In Comparative Example 1, a latent heat storage material molded body was obtained by using glass frit (manufactured by AGC, trade name: CM251-ZL) instead of wollastonite (calcium compound (B)) used in Example 1. 【0113】 Specifically, 3.5 g of latent heat storage material (A-1) and 1.5 g of glass frit were weighed and placed in a mortar, and 2.3 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (product name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain the composition of Comparative Example 1. Subsequently, water was added to the composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical molded body precursors. After drying the precursors at 60°C overnight (about 12 hours), firing was performed under the same conditions as in Example 1 to obtain cylindrical molded bodies with a latent heat storage material:oxide ratio of 70:30 mass% and a diameter of Φ5 mm × H5 mm. Furthermore, compositional analysis of the molded body of Comparative Example 1 was performed using ICP in the same manner as in Example 1, and the calcium concentration was found to be 0.2 mass% (on an oxide basis). 【0114】 <Comparative Example 2> In Comparative Example 2, a latent heat storage material molded body was obtained by using glass fiber (manufactured by Tosoh SGM Co., Ltd., product name: Quartz Wool Coarse) instead of the wollastonite used in Example 1. 【0115】 Specifically, 3.5 g of latent heat storage material (A-1) and 1.5 g of glass fiber were weighed and placed in a mortar, and 2.3 g of ethanol was added and mixed while maintaining a moist state. After standing at room temperature for about 1 hour to allow it to dry completely, 0.1 g of methylcellulose (product name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain the composition of Comparative Example 2. Subsequently, water was added to this composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical mold precursors. After drying at 60°C overnight (about 12 hours), firing was performed under the same conditions as in Example 1 to obtain cylindrical molds with a latent heat storage material:oxide ratio of 70:30 mass% and a diameter of Φ5 mm × H5 mm. Furthermore, compositional analysis of the molded body of Comparative Example 2 was performed using ICP in the same manner as in Example 1, and the calcium concentration was found to be 0.1 mass% (oxide equivalent). 【0116】 <Comparative Example 3> By using silica derived from silica sol instead of the wollastonite used in Example 1, a latent heat storage material molded body of Comparative Example 3 was obtained. 【0117】 Specifically, 3.5 g of latent heat storage material (A-1) and silica sol (manufactured by Nissan Chemical Corporation, trade name: Snowtex N (registered trademark)) were weighed to a solid content of 1.5 g and placed in a mortar. The mixture was kept moist and left to stand at room temperature for about 1 hour, but it did not dry, so it was dried at 80°C overnight (approximately 12 hours) as an additional step. After drying, 0.1 g of methylcellulose (trade name: Metroze (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain the composition of Comparative Example 3. Subsequently, water was added to the composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 precursor cylindrical molded bodies. After drying at 60°C overnight (approximately 12 hours), firing was performed under the same conditions as in Example 1 to obtain cylindrical molded bodies with a latent heat storage material:oxide ratio of 70:30 mass%, and a diameter of Φ5 mm × H5 mm. Furthermore, a compositional analysis of the molded article of Comparative Example 3 was performed using ICP in the same manner as in Example 1, and the calcium concentration was found to be 0.1% by mass (on an oxide basis). 【0118】 <Comparative Example 4> A latent heat storage material molded body of Comparative Example 4 was prepared without using a compound equivalent to calcium compound (B). 【0119】 Specifically, 5.0 g of latent heat storage material (A-1) was weighed, 0.1 g of methylcellulose (product name: Metroze®, manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was placed in a mortar and mixed to obtain the composition of Comparative Example 4. Subsequently, water was added to this composition to prepare a clay, and the clay was placed in a metal mold and extruded to form 10 cylindrical mold precursors. After drying at 60°C overnight (approximately 12 hours), firing was performed under the same conditions as in Example 1 to obtain cylindrical molds with a latent heat storage material:oxide ratio of 100:0 mass% and a diameter of Φ5 mm × H5 mm. Furthermore, compositional analysis of the molded body of Comparative Example 4 was performed using ICP in the same manner as in Example 1, and the calcium concentration was found to be 0.1 mass% (on an oxide basis). 【0120】 For each sample of the heat storage material molded articles of Examples 1 to 6 and Comparative Examples 1 to 4 prepared as described above, metal leakage, formability, and crush strength were evaluated. Each evaluation was carried out according to the evaluation method shown below. The results are shown in Table 1. 【0121】 <Metal leakage> The presence or absence of metallic-looking foreign matter was visually checked on the surface of the sample. If no metallic-looking foreign matter was found, it was determined that there was "no" metal leakage; if one or more metallic-looking foreign matter was found, it was determined that there was "metal leakage". 【0122】 <Moldability> Out of 10 samples, if 70% or more had no visible defects such as cracks or chips, it was judged to have good moldability and was deemed acceptable. Samples with less than 70% of the percentage were judged to have poor moldability and were deemed unacceptable. For example, as shown in Table 1, in Example 1, out of the 10 samples of heat storage material molded bodies produced as described above, no visible defects such as cracks or chips were observed in 9 of them. Therefore, the heat storage material molded bodies of Example 1 had a percentage of 90% with no visible defects, had good moldability, and were deemed acceptable. 【0123】 <Strength Test> For samples that showed no external defects such as cracks or chips, the crush strength when pressure was applied to the side of the cylindrical sample was measured using a Kiya hardness tester. Each sample was measured individually, for a total of five samples. Samples with an average value of 200N or higher were deemed to pass, and those with an average value below 200N were deemed to fail. Comparative Example 3 failed the moldability test, so that test was not performed. 【0124】 [Table 1] 【0125】 As shown in Table 1, the heat storage material molded articles of Examples 1 to 6 yielded good results in all aspects: metal leakage, formability, and crush strength. On the other hand, the molded article of Comparative Example 1 showed metal leakage and also had low crush strength. Furthermore, the molded article of Comparative Example 2 showed metal leakage, the molded article of Comparative Example 3 had poor formability, and Comparative Example 4 showed metal leakage and also had poor crush strength. 【0126】 Next, the heat storage capacity of each sample of the heat storage material molded bodies from Examples 1 to 6 and the molded bodies obtained in Comparative Examples 1 to 4 was measured according to the following method. 【0127】 <Heat storage capacity measurement> The amount of heat stored was measured using a TG-DSC (TA Instruments, product name: SDT650). The cylindrical sample obtained in Example 1 was ground in a mortar. The ground sample was placed in an alumina sample pan and heated to 700°C at a heating rate of 10°C / min under a nitrogen flow of 20 ml / min, and the amount of heat stored (latent heat / heat absorbed) was measured (1st measurement). Then, the temperature was lowered to 500°C at a cooling rate of 5°C / min, and the amount of heat released (latent heat / heat released) was measured (1st measurement). The temperature was raised again to 700°C at a heating rate of 10°C / min, and the amount of heat stored (latent heat / heat absorbed) was measured (2nd measurement). Then, the temperature was lowered to 500°C at a cooling rate of 5°C / min, and the amount of heat released (latent heat / heat released) was measured (2nd measurement). Furthermore, the same procedure as the second time was repeated to measure the amount of heat stored (latent heat amount / heat absorbed) and the amount of heat released (latent heat amount / heat released) (third time). As an example, the results of Example 1 are shown in Table 2. 【0128】 [Table 2] 【0129】 As can be seen from the results above, the latent heat storage material molded body obtained in Example 1 did not show a decrease in heat storage capacity or heat release capacity even after repeating the measurement three times. In other words, it was confirmed that the latent heat storage material molded body obtained in the example can repeatedly function as a heat storage body. Furthermore, the latent heat storage material molded bodies obtained in Examples 2 to 6 also yielded similar results to Example 1. On the other hand, in the molded bodies of Comparative Examples 1 to 4, the heat storage capacity and heat release capacity decreased after repeating the measurement three times. 【0130】 This application is based on Japanese Patent Application No. 2022-172814, filed on 28 October 2022, the disclosures of which are referenced and incorporated in whole.
Claims
[Claim 1] The latent heat storage material (A) comprises core particles containing an Al-Si alloy coated with an aluminum oxide film, and a calcium compound (B). A latent heat storage material molded body obtained by molding a latent heat storage material composition in which the content ratio of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less, A latent heat storage material molded body containing 3% to less than 20% by mass of calcium in terms of oxide. [Claim 2] The latent heat storage material molded article according to claim 1, wherein the latent heat storage material composition comprises an inorganic binder and / or an organic binder. [Claim 3] The latent heat storage material molded body according to claim 1 or 2, wherein the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite. [Claim 4] A latent heat storage material molded body according to claim 1 or 2, having one or more shapes selected from the group consisting of cylindrical, pellet-shaped, spherical, ring-shaped, plate-shaped, rod-shaped, and honeycomb-shaped. [Claim 5] (1) A latent heat storage material (A) in which core particles containing an Al-Si alloy are coated with an aluminum oxide film is mixed with a calcium compound (B) such that the ratio of the content (mass) of the calcium compound (B) to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less to obtain a latent heat storage material composition. A method for producing a latent heat storage material molded body, comprising (2) molding the latent heat storage material composition, and (3) firing it at 700°C or higher, A method for producing the latent heat storage material molded body, wherein the latent heat storage material contains 3% by mass or more and less than 20% by mass of calcium in terms of oxide. [Claim 6] Furthermore, the manufacturing method according to claim 5, wherein an inorganic binder and / or an organic binder are added and mixed. [Claim 7] The manufacturing method according to claim 5 or 6, wherein the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite. [Claim 8] The manufacturing method according to claim 5 or 6, wherein the latent heat storage material composition is molded into one or more shapes selected from the group consisting of cylindrical, pellet-shaped, spherical, ring-shaped, plate-shaped, rod-shaped, and honeycomb-shaped. [Claim 9] The manufacturing method according to claim 5 or 6, wherein the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium.