Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/02—Materials undergoing a change of physical state when used
  • C09K5/06—Materials undergoing a change of physical state when used the change of state being from liquid to solid or vice versa
  • C09K5/063—Materials absorbing or liberating heat during crystallisation; Heat storage materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/16—Metallic particles coated with a non-metal
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0408—Light metal alloys
  • C22C1/0416—Aluminium-based alloys
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/02—Alloys based on aluminium with silicon as the next major constituent

Definitions

• the present invention relates to a latent heat storage material composition, a latent heat storage material molded body obtained by molding the latent heat storage material composition, and a method for manufacturing the latent heat storage material molded body.
• Known methods for storing heat include sensible heat storage, which utilizes temperature changes (e.g., Patent Document 1), and latent heat storage, which utilizes phase changes in a substance (e.g., Patent Document 2).
• sensible heat storage technology is capable of storing heat at high temperatures, but has the problem of low heat storage density because it only utilizes sensible heat resulting from temperature changes in a substance.
• Latent heat storage technology which uses the latent heat of molten salts and the like to store heat, has been proposed as a way to solve this problem.
• Patent Document 3 discloses inventions such as a latent heat storage capsule characterized by having one, two or three layers of metal coating formed on the surface of a latent heat storage material, and a manufacturing method for a latent heat storage capsule characterized by coating a latent heat storage material with a metal coating by electrolytic plating.
• Patent Document 4 also discloses an alloy-based latent heat storage microcapsule (Micro-Encapsulated Phase Change Material: hereinafter abbreviated as MEPCM) in a latent heat storage body composed of a core and a shell that covers the core, in which the core particles are subjected to a chemical coating treatment and further to a thermal oxidation treatment to form an oxide coating on the shell.
• MEPCM alloy-based latent heat storage microcapsule
• the present invention was made in consideration of these problems with conventional MEPCM, and aims to provide a latent heat storage material composition that, when molded into a molded product, is less likely to cause defects such as metal leakage or cracks, has sufficient mechanical strength, and also has good heat storage and heat dissipation properties.
• Another object of the present invention is to provide a latent heat storage material molded body that is resistant to defects such as metal leakage and cracks, has sufficient mechanical strength, and has good heat storage and heat dissipation properties, and a method for producing the same.
• the inventors conducted extensive research to achieve the above object and came up with the present invention. As a result, they discovered that the above problems could be solved by a latent heat storage material composition containing a latent heat storage material and a calcium compound in a specified ratio, as well as a latent heat storage material molded body using the same and a method for producing the molded body, leading to the completion of the present invention.
• the content ratio of the calcium compound (B) relative to the latent heat storage material (A) is 1 mass % or more and 40 mass % or less.
• the latent heat storage material composition described in 1 above preferably contains an inorganic binder and/or an organic binder.
• the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite.
• One aspect of the present invention is 4.
• the calcium content is 3% by mass or more and less than 20% by mass, calculated as the oxide.
• the molded body has one or more shapes selected from the group consisting of a cylindrical shape, a pellet shape, a spherical shape, a ring shape, a plate shape, a rod shape, and a honeycomb shape.
• 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) of the calcium compound (B) relative to the latent heat storage material (A) is 1 mass% or more and 40 mass% or less to obtain a latent heat storage material composition; (2) molding the latent heat storage material composition; and (3) firing the composition at 700° C. or higher.
• the calcium compound (B) is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite.
• the latent heat storage material composition into one or more shapes selected from the group consisting of a cylinder, a pellet, a sphere, a ring, a plate, a rod, and a honeycomb.
• the latent heat storage material molding contains calcium in an oxide equivalent of 3% by mass or more and less than 20% by mass.
• the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium.
• One embodiment of the present invention is a latent heat storage material composition
• a latent heat storage material composition comprising 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), in which the content (mass) of the calcium compound (B) relative to the latent heat storage material (A) is 1 mass% or more and 40 mass% or less.
• Another aspect of the present invention is a latent heat storage material molded body obtained by molding the latent heat storage material composition.
• the latent heat storage material molded body is less susceptible 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.
• Another embodiment of the present invention is a method for producing 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 at 700°C or higher.
• the latent heat storage material molded body obtained by this manufacturing method is less susceptible to defects such as metal leakage and cracks (i.e., has excellent processing stability), has sufficient mechanical strength, and further has good heat storage and heat dissipation properties.
• X to Y means a range including the numerical values (X and Y) described before and after it as the lower and upper limits, and means “X or more and Y or less.”
• concentration “%” means mass concentration “mass %” unless otherwise specified, and ratios are mass ratios unless otherwise specified.
• 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), and the content ratio of the calcium compound (B) to the latent heat storage material (A) is 1 mass % or more and 40 mass % or less.
• the latent heat storage material composition having this configuration when the latent heat storage material composition having this configuration is molded, defects such as metal leakage and cracks are unlikely to occur (i.e., it 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 exerts this effect is not clear, but the following is thought to be the case.
• the calcium compound (B) acts on the aluminum oxide coating of the latent heat storage material (A), making the coating less likely to crack. This suppresses metal leakage. Furthermore, since the calcium compound (B) promotes adhesion between the latent heat storage materials (A), it is believed that cracking of the molded body itself is suppressed and the mechanical strength is also improved. In addition, since metal leakage is less likely to occur, it is believed that the heat storage and heat dissipation properties are sufficiently maintained even after molding. Note that the above mechanism is based on speculation, and the present invention is not limited to the above mechanism in any way.
• the latent heat storage material composition and latent heat storage material molded body preferably contain calcium compound (B) in an amount of 3% by mass or more and 20% by mass or less, preferably 5% by mass or more, preferably 8% by mass or more, and preferably 10% by mass or more, calculated as an oxide.
• 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.
• the lower limit of the content of the latent heat storage material (A) in the latent heat storage material composition is, in terms of solid content, 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, in terms of solid content, 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.
• the content of the latent heat storage material (A) in the latent heat storage material composition may be, in terms of solid content, 60% by mass or more and 97% by mass or less, 60% by mass or more and 95% by mass or less, 60% by mass or more and 90% by mass or less, 60% by mass or more and 85% by mass or less, 60% by mass or more and 80% by mass or less, 65% by mass or more and 97% by mass or less, 65% by mass or more and 95% by mass or less, 65% by mass or more and 90% by mass or less, 65% by mass or more and 85% by mass or less, 65% by mass or more and 80% by mass or less, 70% by mass or more and 97% by mass or less, 70% by mass or more and 95% by mass or less, 70% by mass or more and 90% by mass or less, 70% by mass or more and 85% by mass or less, 70% by mass or more and 80% by mass or less, 75% by mass or more and 97% by mass or less, 75% by mass or more and 97% by mass or less,
• the average particle size of the latent heat storage material (A) is preferably 1 ⁇ m or more and 600 ⁇ m or less, more preferably 5 ⁇ m or more and 250 ⁇ m or less, and even more preferably 10 ⁇ m or more and 150 ⁇ m or less.
• the Al-Si alloy contained in the core particles of the latent heat storage material (A) may be an alloy made of aluminum and silicon.
• the content of silicon in the Al-Si alloy is preferably 4% by mass or more and 40% by mass or less, more preferably 8% by mass or more and 30% by mass or less, even more preferably 10% by mass or more and 25% by mass or less, and particularly preferably 12% by mass or more and 25% by mass or less.
• the content of aluminum in the Al-Si alloy is preferably 60% by mass or more and 96% by mass or less, more preferably 70% by mass or more and 92% by mass or less, and even more preferably 75% by mass or more and 90% by mass or less. If the content of silicon and aluminum in the Al-Si alloy is within the above range, the volume expansion coefficient during the phase change from solid phase to liquid phase can be suppressed low, so that the durability as MEPCM can be increased and metal leakage is less likely to occur.
• Al-Si alloys may contain unavoidable impurities in addition to aluminum and silicon.
• "Avoidable impurities” refers to those that are present in the raw materials or that are inevitably mixed in during the manufacturing process. Although these unavoidable impurities are not necessary in nature, they are permitted 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) at 0.2 mass% or less (lower limit 0 mass%), and copper (Cu), manganese (Mn), lead (Pb), cadmium (Cd), etc. at 0.01 mass% or less (lower limit 0 mass%) or 0.005 mass% or less (lower limit 0 mass%).
• the proportion of the 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.
• the proportion of the Al-Si alloy contained in the core particles is within the above range, the functions as a latent heat storage material, such as the amount of heat stored and released, are further improved.
• Al-Si alloys can be manufactured using previously known methods.
• the average particle diameter of the core particles of the latent heat storage material (A) is preferably 1 ⁇ m or more, more preferably 5 ⁇ m or more, and even more preferably 10 ⁇ m or more. By having the particle diameter within the above range, the ratio of the shell portion to the core portion responsible for heat storage becomes appropriate, and a decrease in heat storage density can be prevented.
• the average particle diameter of the core particles of the latent heat storage material (A) according to one embodiment is preferably 500 ⁇ m or less, more preferably 200 ⁇ m or less, and particularly preferably 100 ⁇ m or less.
• the latent heat storage material expands and contracts as the core portion melts and solidifies, but by having the particle diameter within the above range, the ratio of the core to the shell becomes appropriate, and metal leakage that occurs when the shell cannot withstand stress can be effectively prevented. That is, the average particle size of the core particles of the latent heat storage material (A) according to one embodiment is preferably 1 ⁇ m or more and 500 ⁇ m or less, more preferably 5 ⁇ m or more and 200 ⁇ m or less, and even more preferably 10 ⁇ m or more and 100 ⁇ m or less.
• the average particle diameter of the core particles is a value measured by the method described in the Examples.
• the cumulative 90% volume diameter of the core particles of the latent heat storage material (A) is preferably 10 ⁇ m or more and 100 ⁇ m or less, more preferably 20 ⁇ m or more and 80 ⁇ m or less, and even more preferably 30 ⁇ m or more and 70 ⁇ m or less.
• the aluminum oxide coating is not particularly limited, but may be a single layer or may have multiple layers.
• the aluminum oxide coating contains ⁇ -Al 2 O 3 as a component.
• the components constituting the aluminum oxide coating are not limited to aluminum oxide only, and may contain other elements and/or unavoidable impurities.
• the thickness of the aluminum oxide coating is not particularly limited, but is preferably 0.1 ⁇ m to 10 ⁇ m, and more preferably 0.5 ⁇ m to 5 ⁇ m. By having the thickness of the aluminum oxide coating within the above range, the aluminum oxide coating can sufficiently cover the surface of the core particles made of an Al-Si alloy while maintaining heat storage and heat dissipation properties, making it less likely for metal leakage to occur.
• the thickness of the aluminum oxide coating can be calculated by subtracting the average particle size of the core particles from the average particle size of the latent heat storage material, and then dividing the result by 2.
• the method for producing the latent heat storage material (A) is not particularly limited, and a known method can be used. However, it is preferable to use aluminum hydroxide having a boehmite crystal structure as the aluminum raw material for forming an aluminum oxide coating on the core particles made of an Al-Si alloy. By using aluminum hydroxide having a boehmite (AlOOH) crystal structure, a dense oxide coating can be formed.
• the aluminum oxide coating can be formed by introducing core particles made of an Al-Si alloy into an aqueous solution containing aluminum hydroxide whose crystal structure is boehmite.
• the content of aluminum hydroxide 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 the core particles.
• the pH of the aqueous solution at room temperature is preferably 6.0 or more and less than 11.0, more preferably 7.0 to 10.5, and even more preferably 8.5 to 10.0.
• 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, more preferably 0.5 to 5 hours.
• the method for producing the latent heat storage material (A) it is preferable to further perform a thermal oxidation treatment after forming an aluminum oxide coating on the core particles. This allows the aluminum oxide coating formed on the surface of the core particles to be further oxidized, and the MEPCM, which is crystalline Al 2 O 3 , can be obtained.
• the temperature at which the thermal oxidation treatment is carried out is preferably higher than the melting point of the Al-Si alloy that is the component of the core portion.
• the melting point is 580°C, and it is preferable to heat at a temperature higher than that (for example, 700°C or higher). It is more preferable to carry out the treatment at 800°C or higher, and even more preferable to carry out the treatment at 900°C or higher.
• the aluminum oxide film formed by the heat treatment has a ⁇ -Al 2 O 3 crystal structure at a relatively low temperature of 800°C or lower, while a coating having an ⁇ -Al 2 O 3 crystal structure, which is considered to be chemically stable, is obtained at a relatively high temperature of 880°C or higher.
• the upper limit is not particularly limited, but it is preferable to set it to 1200°C or lower.
• the time for the heat treatment is preferably 0.5 hours to 12 hours, and more preferably 2 hours to 5 hours.
• the thermal oxidation treatment of the heat storage latent heat material (A) can be carried out simultaneously with the step (step 3) of firing the molded body described below. Also, the thermal oxidation treatment of the heat storage latent heat material (A) and the step (step 3) of firing the molded body may be carried out separately. By carrying out the thermal oxidation treatment and firing simultaneously, the manufacturing process can be simplified, and improved production efficiency and reduced production costs can be expected.
• the latent heat storage material composition of the present invention contains a calcium compound (B).
• the calcium compound (B) is contained in the latent heat storage material composition in a ratio of 1 mass % to 40 mass % relative to the latent heat storage material (A) (calcium compound (B) content/latex heat storage material (A) content ⁇ 100 (mass %)).
• calcium is preferably contained in an amount of 3 mass% or more and less than 20 mass%, more preferably 5 mass% or more, even more preferably 8 mass% or more, and particularly preferably 10 mass% or more, calculated as oxide.
• the upper limit is more preferably 18.5 mass% or less, and even more preferably 15 mass% or less.
• the calcium content (in oxide terms) 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 into oxide.
• Calcium compounds are materials that contain calcium, and are not limited to single compounds, but also include minerals that contain the compound as the main component (for example, wollastonite, which contains calcium silicate as the main component).
• main component refers to a compound that accounts for 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more of the total amount.
• Examples of the calcium compound (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 hydroxyphosphate, calcium pyrophosphate, calcium hypochlorite, calcium chlorate, calcium chromate, calcium tungstate, calcium molybdate, calcium magnesium carbonate (a 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, and two or more of these may be used in combination.
• inorganic calcium compounds such as calcium oxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide
• calcium compound (B) is preferably calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, or wollastonite, and more preferably is one or more selected from the group consisting of calcium hydroxide, calcium carbonate, and wollastonite.
• the 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 hydroxyphosphate, 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.
• the calcium compound (B) may be one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite, 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.
• calcium silicate includes calcium silicates having various chemical compositions, such as CaSiO3 , Ca2SiO4 , Ca3SiO5 , and Ca3Si2O7 .
• the content ratio of the calcium compound (B) relative to the latent heat storage material (A) is 1% by mass or more and 40% by mass or less, with the lower limit of this ratio being 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.
• the ratio may be 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, 10% by mass or more and 40% by mass or less, 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, 15%
• the latent heat storage material composition and the molded product of the latent heat storage material composition can maintain good heat storage and heat release properties, while the mechanical strength and processing stability of the molded product can be improved.
• the latent heat storage material composition according to an embodiment preferably contains an inorganic binder and/or an organic binder. By containing these binders, the processing stability when the latent heat storage material composition is molded is further improved, and the mechanical strength of the molded product itself is further improved.
• the inorganic binder is not particularly limited, but examples thereof include zirconia, silica, alumina, and titania. Among these inorganic binders, silica and/or alumina are preferable, and it is more preferable that the binder contains at least silica.
• organic binders include celluloses such as methyl cellulose, carboxymethyl cellulose, hydroxyalkyl methyl cellulose, sodium carboxymethyl cellulose, and ethyl cellulose; 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) described above.
• a binder it is preferable to use at least cellulose as the binder, and it is even more preferable to use at least methylcellulose, since this improves processing stability during molding and also improves the mechanical strength of the molded product itself.
• the binder content in the latent heat storage material composition is, in terms of solid content, preferably 15 mass% or less, more preferably 10 mass% or less, and even more preferably 5 mass% or less, relative to the mass of the total solid content of the latent heat storage material composition.
• the lower limit of the binder content is not particularly limited, but is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.4 mass% or more, particularly preferably 0.5 mass% or more, and most preferably 1 mass% or more, in terms of solid content.
• the content of the binder in terms of solid content, may be, relative to the mass of the total solid content of the latent heat storage material composition, 0.1 mass% or more and 15 mass% or less, 0.1 mass% or more and 10 mass% or less, 0.1 mass% or more and 5 mass% or less, 0.2 mass% or more and 15 mass% or less, 0.2 mass% or more and 10 mass% or less, 0.2 mass% or more and 5 mass% or less, 0.4 mass% or more and 15 mass% or less, 0.4 mass% or more and 10 mass% or less, 0.4 mass% or more and 5 mass% or less, 0.5 mass% or more and 15 mass% or less, 0.5 mass% or more and 10 mass% or less, 0.5 mass% or more and 5 mass% or less, 1 mass% or more and 15 mass% or less, 1 mass% or more and 10 mass% or less, or 1 mass% or more and 5 mass% or less.
• the binder content within the above range, the heat storage and heat release 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 the latent heat storage material composition is molded is more sufficiently improved, and the mechanical strength of the molded product can also be improved.
• the above binder content is the total value of the contents of each binder.
• composition of the present invention may contain other components, such as oxides such as magnesia (magnesium oxide) and ceria (cerium (IV) oxide), glass frit, and sintering aids such as silicon carbide.
• oxides such as magnesia (magnesium oxide) and ceria (cerium (IV) oxide
• glass frit such as glass frit
• sintering aids such as silicon carbide.
• the latent heat storage material molded body is a latent heat storage material molded body using 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 susceptible to defects such as metal leakage and cracking, has sufficient mechanical strength, and further has good heat storage and heat dissipation properties.
• the latent heat storage material molded body according to one embodiment preferably contains calcium in an oxide equivalent amount of 3% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, and particularly preferably 10% by mass or more.
• the upper limit of calcium contained in the latent heat storage material molded body according to one embodiment is preferably less than 20% by mass in oxide equivalent. That is, the latent heat storage material molded body according to one embodiment preferably contains calcium in an oxide equivalent amount of 3% by mass or more and less than 20% by mass, 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.
• the mechanical strength of the latent heat storage material molded body becomes more sufficient.
• the calcium content (converted into oxide) in the latent heat storage material compact can be calculated by analyzing the concentration of each element using an ICP emission spectrometer and then converting it into oxide. More specifically, the method described in the examples can be used.
• the latent heat storage material molded body is not particularly limited, but preferably has one or more shapes selected from the group consisting of a cylindrical shape, a pellet shape, a spherical shape, a ring shape, a plate shape, a rod shape, and a honeycomb shape. By having such a shape, the latent heat storage material molded body becomes easy to handle industrially.
• the size of the latent heat storage material molded body is not particularly limited.
• the shape of the cut surface (the shape of the outer periphery) is a shape other than a polygon
• the long side of the rectangle inscribed by the cut surface 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.
• the upper limit of the long side is not particularly limited, but 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.
• the major axis is 0.1 mm or more and 50 cm or less, 0.1 mm or more and 25 cm or less, 0.1 mm or more and 15 cm or less, 0.1 mm or more and 10 cm or less, 0.1 mm or more and 5 cm or less, 0.1 mm or more and 1 cm or less, 0.5 mm or more and 50 cm or less, 0.5 mm or more and 25 cm or less, 0.5 mm or more and 15 cm or less, 0.5 mm or more and 10 cm or less, 0.5 mm or more and 5 cm or less, 0.5 mm or more and 1 cm or less, 1 mm or more and 50 cm or less, 1 mm or more and 25 cm or less, 1 mm or more and 15 cm or less, 1 mm or more and 10 cm or less, 1 mm or more and 5 cm or less, 1 mm or less It may be 1 cm or less, 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 or less
• the major axis (diameter in the case of a circle) of an 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.
• the major axis may be 200 cm or less, 150 cm or less, 100 cm or less, 50 cm or less, or 25 cm or less.
• the major axis is 0.5 mm or more and 200 cm or less, 0.5 mm or more and 150 cm or less, 0.5 mm or more and 100 cm or less, 0.5 mm or more and 50 cm or less, 0.5 mm or more and 25 cm or less, 1 mm or more and 200 cm or less, 1 mm or more and 150 cm or less, 1 mm or more and 100 cm or less, 1 mm or more and 50 cm or less, 1 mm or more and 25 cm or less, 2 mm or more and 200 cm or less, 2 mm or more and 150 cm or less, 2 mm or more and 100 cm or less, 2 mm or more and 50 cm or less, 2 mm or more and 25 cm or less, 5 mm or more and 200 cm or less, 5 mm or more and 150 cm or less, 5 mm or more and 100 cm or less, 5 mm or more and 50 cm or less, 5 mm or more and 25 cm or less, 1 cm or more and 200 cm or less, 1 cm or more and 150 cm or less, 1 mm
• the lower limit of the diameter of the bottom surface 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 bottom surface 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.
• 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 20 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.
• 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.
• 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.
• the height of the cylinder may be 1 mm or more to 20 mm or less, 1 mm or more to 15 mm or less, 1 mm or more to 10 mm or less, 1 mm or more to 8 mm or less, 2 mm or more to 20 mm or less, 2 mm or more to 15 mm or less, 2 mm or more to 10 mm or less, 2 mm or more to 8 mm or less, 3 mm or more to 20 mm or less, 3 mm or more to 15 mm or less, 3 mm or more to 10 mm or less, 3 mm or more to 8 mm or less, 4 mm or more to 20 mm or less, 4 mm or more to 15 mm or less, 4 mm or more to 10 mm or less, or 4 mm or more to 8 mm or less.
• the bottom diameter and height are within the above ranges, making it easy to fill it as a
• the above-mentioned range of the diameter of the bottom surface and the range of the height of the cylinder can be appropriately combined.
• the height of the cylinder may be 1 mm or more and 20 mm or less; if the diameter of the bottom surface is 2 mm or more and 15 mm or less, the height of the cylinder may be 2 mm or more and 15 mm or less; if the diameter of the bottom surface is 3 mm or more and 10 mm or less, the height of the cylinder may be 3 mm or more and 10 mm or less; and if the diameter of the bottom surface is 4 mm or more and 8 mm or less, the height of the cylinder may be 4 mm or more and 8 mm or less.
• the external shape of the latent heat storage material molding is a substantially rectangular prism or cylinder having a first end face and a second end face, and further has a plurality of cells penetrating from the first end face to the second end face.
• the shape of the first end face and the second end face is not particularly limited, and may be a polygon such as a triangle, a rectangle, a pentagon, or a hexagon, or may be an ellipse or a circle.
• the area of the first end face and the second end face is not particularly limited, but is preferably 100 cm 2 or more and 1000 cm 2 or less, more preferably 150 cm 2 or more and 750 cm 2 or less, and more preferably 200 cm 2 or more and 500 cm 2 or less.
• the height of the square column 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.
• the shape of the cells is not particularly limited, but the shape of the cross section perpendicular to the direction of the penetration of the cells may be a triangle, a rectangle, a pentagon, a hexagon, an octagon, a circle, or an ellipse.
• the area of the cross section perpendicular to the direction of the penetration of the cells is not particularly limited, but is preferably 0.05 cm 2 or more and 25 cm 2 or less, more preferably 0.1 cm 2 or more and 15 cm 2 or less, even more preferably 0.25 cm 2 or more and 10 cm 2 or less, and particularly preferably 0.5 cm 2 or more and 5 cm 2 or less.
• the method for producing a latent heat storage material molded body of the present invention comprises the steps of: (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) of the calcium compound (B) relative to the latent heat storage material (A) is 1 mass% or more and 40 mass% or less to obtain a latent heat storage material composition (step 1); (2) forming the latent heat storage material composition (step 2); and (3) firing the composition at 700° C. or higher (step 3).
• 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 with a calcium compound (B) so that the content (mass) of the calcium compound (B) relative to the latent heat storage material (A) is 1 mass% or more and 40 mass% or less, thereby obtaining a latent heat storage material composition.
• the latent heat storage material (A) and calcium compound (B) used in this step are similar to the preferred forms described in the "Latent Heat Storage Material (A)” and “Calcium Compound (B)” sections, respectively.
• the calcium compound (B) used in this step is one or more selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, limestone, gypsum, and wollastonite.
• the latent heat storage material (A) and the calcium compound (B) are mixed so that the content (mass) of the calcium compound (B) relative to the latent heat storage material (A) in the latent heat storage material composition is 1 mass% or more and 40 mass% or less, and the preferred range for this ratio is the same as the preferred form explained in the above-mentioned section on calcium compound (B).
• 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 mixed uniformly.
• so-called wet mixing in which the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium, is preferred.
• a dispersion medium By mixing together with a dispersion medium, the latent heat storage material (A) and the calcium compound (B) can be mixed more uniformly.
• 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.
• 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; aromatic hydrocarbons such as benzene, toluene, and xylene.
• the dispersion medium is preferably water and/or a hydrophilic organic solvent (lower (e.g., carbon number 1 to 3) alcohols 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., carbon number 1 to 3).
• the dispersion medium may be used in combination with one that is used as a dispersion medium for inorganic binders, etc.
• the dispersing medium mixed with the latent heat storage material (A) and the calcium compound (B) is preferably 10% by mass or more and 150% by mass or less, more preferably 15% by mass or more and 100% by mass or less, and even more preferably 20% by mass or more and 90% by mass or less, based on the total mass (solid content) of the latent heat storage material (A) and the calcium compound (B).
• the amount of the dispersing medium within this range, the latent heat storage material (A) and the calcium compound (B), etc. can be mixed more sufficiently and uniformly.
• the dispersion medium used in the mixing so that the amount of the dispersion medium is less than a certain amount. Therefore, it is preferable that the dispersion medium is volatile.
• an inorganic binder and/or an organic binder it is preferable to add and mix an inorganic binder and/or an organic binder.
• the types of inorganic binder and organic binder and the binder content in the latent heat storage material composition are the same as those described in the "Binder" section above. Adding a binder makes it easier to mold the latent heat storage material composition, reduces cracks in the molded product, and further improves the mechanical strength.
• the latent heat storage material (A) and the calcium compound (B) it is preferable to mix the latent heat storage material (A) and the calcium compound (B) together, and then add and mix an inorganic binder and/or an organic binder.
• the latent heat storage material (A) and the calcium compound (B) are mixed together with a dispersion medium, it is preferable to add and mix the inorganic binder and/or the organic binder after the dispersion medium is sufficiently dried. In this way, the components contained in the latent heat storage material composition can be mixed more uniformly, cracks and the like of the molded product can be more effectively suppressed, and the mechanical strength can be further improved.
• a method for producing a latent heat storage material molded body 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 the molded body at 700°C or higher (step 3).
• the latent heat storage material composition is preferably molded into one or more shapes selected from the group consisting of a cylinder, a pellet, a sphere, a ring, a plate, a rod, and a honeycomb, and more preferably molded into a cylinder.
• the latent heat storage material molded body becomes easy to handle industrially.
• the size of the latent heat storage material molded body is similar to the preferred shape explained in the section on latent heat storage material molded body.
• step 2 the method for forming the latent heat storage material composition into the desired shape is not particularly limited, but examples include uniaxial pressing, isotropic pressing, injection molding, extrusion molding, rolling granulation, and casting, with extrusion molding being preferably used.
• step 2 a small amount of solvent may be added to the latent heat storage material composition, and the latent heat storage material composition and the solvent may be mixed and then molded into a desired shape.
• the "dispersion medium" described in the section on step 1 may be used as the desired solvent.
• 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.
• 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, or 850°C or higher and 1000°C or lower.
• a step of drying the molded latent heat storage material composition may be included between steps 2 and 3.
• the occurrence of defects such as cracks can be effectively suppressed in the manufactured latent heat storage material molded body.
• a degreasing step may be included in which the molded latent heat storage material composition is heated at a predetermined temperature prior to the firing step 3.
• the predetermined temperature in the degreasing step is not particularly limited, but is preferably 250°C or higher and 600°C or lower. In addition, it is preferable to maintain the predetermined temperature for 1 hour or higher and 3 hours or lower in the degreasing step.
• the latent heat storage material molded body produced by the manufacturing method according to one embodiment may contain calcium in an oxide equivalent amount of 3% by mass or more and less than 20% by mass.
• the preferred range of the amount of calcium contained in the latent heat storage material molded body is the same as the preferred form explained in the section on latent heat storage material molded bodies. By having the calcium content (oxide equivalent) within these ranges, the mechanical strength of the latent heat storage material molded body becomes more sufficient.
• the thermal oxidation treatment of the heat storage latent heat material (A) and the firing in step 3 can be carried out simultaneously. Also, the thermal oxidation treatment of the heat storage latent heat material (A) and the firing in step 3 may be carried out separately. By carrying out the thermal oxidation treatment and the firing in step 3 simultaneously, the production process can be simplified, and improved production efficiency and reduced production costs can be expected.
• ⁇ Measurement of average particle size> [Average particle size of core particles]
• the measurement was carried out using a laser diffraction particle size distribution analyzer LA-950V2 manufactured by HORIBA. Specifically, the 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 distribution was measured using the particle size distribution analyzer. The cumulative 50% volume diameter value was taken as the average particle size.
• Average particle size of latent heat storage material (A-1) The measurement was carried out using a laser diffraction particle size distribution analyzer LA-950V2 manufactured by HORIBA. Specifically, the 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 distribution was measured using the particle size distribution analyzer. The cumulative 50% volume diameter value was taken as the average particle size.
• composition analysis of molded body The composition of the molded body was analyzed using an ICP optical emission spectrometer (hereinafter, referred to as ICP) of iCAP6000 SERIES manufactured by Thermo Fisher Scientific Co., Ltd. The concentration of each element was analyzed by ICP, and then converted into an oxide.
• ICP ICP optical emission spectrometer
• the latent heat storage material composition and latent heat storage material composition of each Example and Comparative Example were prepared according to the following procedure.
• Core particles made of an Al-Si alloy (Al-12 wt%Si) with a mass ratio of Al of 88 mass% and a mass ratio of Si of 12 mass% were prepared.
• the average particle diameter of these core particles was 31.9 ⁇ m, and the cumulative 90% volume diameter was 48.4 ⁇ m.
• 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, suction filtration was performed, and the mixture was dried to obtain a powder latent heat storage material (A-1).
• the average particle size of the obtained latent heat storage material (A-1) was 38.8 ⁇ m.
• Example 1 Wollastonite was used as the calcium compound (B). Specifically, 4.0 g of the latent heat storage material (A-1) of Synthesis Example 1 and 1.0 g of wollastonite (manufactured by Kinsei Matec, trade name: SH-1250) were weighed in an evaporating dish, and 3.1 g of ethanol was added to the mixture to make it wet and mixed. After leaving the mixture to stand at room temperature for about 1 hour to thoroughly dry, 0.1 g of methylcellulose (trade name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain a latent heat storage material composition.
• methylcellulose trade name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.
• the precursor of the green body was fired using an HPM-1G gas replacement muffle furnace manufactured by AS ONE Corporation. Specifically, a ceramic crucible containing a cylindrical green body was placed in a muffle furnace, and fired under air flow of 1.0 L/min, heating rate of 5°C/min, firing conditions of 1000°C, and 1 h to obtain a latent heat storage material green body. When the temperature reached 530°C, the temperature (530°C) was maintained for 2 hours to perform degreasing and remove the organic binder.
• Example 2 A latent heat storage material molding was obtained using Milcon, which is a mixture of calcium carbonate (B) and sepiolite, instead of the wollastonite used in Example 1.
• the content of calcium carbonate (B) in Milcon was about 15.2 mass%.
• latent heat storage material A-1
• Milcon manufactured by Showa KDE, product name: MS-2
• a mixture of calcium carbonate and sepiolite a mixture of calcium carbonate and sepiolite
• Example 3 As the calcium compound (B), calcium hydroxide was used in place of the wollastonite used in Example 1, and a latent heat storage material molded body was obtained.
• latent heat storage material A-1
• 1.0 g of calcium hydroxide manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.
• 2.6 g of ethanol was added to the mixture to make it wet and mixed.
• 0.1 g of methylcellulose trade name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.
• water was added to the latent heat storage material composition to prepare a clay, which was then poured into a metal mold and extruded to form 10 cylindrical molded body precursors.
• the precursors were dried overnight (about 12 hours) at 60°C, and then fired under the same conditions as in Example 1 to obtain cylindrical latent heat storage material molded bodies with a latent heat storage material:oxide ratio of 84:16 by mass and a shape of ⁇ 5 mm x H5 mm. Furthermore, a compositional analysis was performed on the latent heat storage material compact obtained using ICP, and the calcium concentration was found to be 18.2% by mass (oxide equivalent).
• Example 4 As the calcium compound (B), calcium carbonate was used in place of the wollastonite used in Example 1, and a latent heat storage material molded body was obtained.
• latent heat storage material A-1
• 1.0 g of calcium carbonate manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.
• 2.3 g of ethanol was added to the mixture to make it wet and mixed.
• 0.1 g of methylcellulose trade name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.
• water was added to the latent heat storage material composition to prepare a clay, which was then poured into a metal mold and extruded to form 10 cylindrical molded body precursors.
• the precursors were dried overnight (about 12 hours) at 60°C, and then fired under the same conditions as in Example 1 to obtain cylindrical latent heat storage material molded bodies with a latent heat storage material:oxide ratio of 88:12 by mass and a shape of ⁇ 5 mm x H5 mm. Furthermore, a compositional analysis of the latent heat storage material compact obtained using ICP revealed that the calcium concentration was 13.6% by mass (oxide equivalent).
• Example 5 As the calcium compound (B), calcium carbonate was used in place of the wollastonite used in Example 1, and silica derived from silica sol was also used as an additive, to obtain a latent heat storage material molded body.
• 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 Industries, Ltd., solid content concentration: 20.3 mass%, product name: Snowtex (registered trademark) N), and 0.1 g of methylcellulose (product name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain a latent heat storage material composition. Next, water was added to the latent heat storage material composition to prepare a clay, which was then poured into a metal mold and extruded to form a precursor of a cylindrical molded body.
• the composition of the obtained latent heat storage material molded body was analyzed using ICP, and the calcium concentration was 9.0 mass% (oxide equivalent).
• 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.
• latent heat storage material A-1
• wollastonite Kinseimatec
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol 197 g
• silica sol solids concentration: 20.3% by mass
• product name Snowtex (registered trademark) N
• alumina product name: AS-50, Resonac, average particle size: 9.8 ⁇ m
• methylcellulose product name: Metrose (registered trademark), Shin-Etsu Chemical
• water was added to the latent heat storage material composition to prepare a clay, which was then poured into a metal mold and extruded to form 10 cylindrical precursor bodies.
• the precursor was dried overnight (about 12 hours) at 60°C, and then fired 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 by mass and a diameter of 6.7 mm and height of 6.7 mm.
• the composition of the latent heat storage material molded body obtained was analyzed using ICP, and the calcium concentration was found to be 3.7% by mass (oxide equivalent).
• Comparative Example 1 Instead of wollastonite (calcium compound (B)) used in Example 1, glass frit (manufactured by AGC, product name: CM251-ZL) was used to obtain a latent heat storage material molded body of Comparative Example 1.
• the composition of the molded body of Comparative Example 1 was analyzed using ICP in the same manner as in Example 1, and the calcium concentration was 0.2 mass% (oxide equivalent).
• Comparative Example 2 A latent heat storage material molded body of Comparative Example 2 was obtained by using glass fiber (manufactured by Tosoh SGM Corporation, product name: Quartz Wool Coarse) instead of the wollastonite used in Example 1.
• the composition of the molded body of Comparative Example 2 was analyzed using ICP in the same manner as in Example 1, and the calcium concentration was 0.1 mass% (oxide equivalent).
• Comparative Example 3 A latent heat storage material molded body of Comparative Example 3 was obtained by using silica derived from silica sol in place of the wollastonite used in Example 1.
• latent heat storage material (A-1) and silica sol manufactured by Nissan Chemical Industries, product name: Snowtex N (registered trademark) were weighed out so that the solid content was 1.5 g and placed in a mortar, mixed in a moist state and left to stand at room temperature for about 1 hour, but since it did not dry, it was further dried overnight (about 12 hours) at 80 ° C. After drying, 0.1 g of methylcellulose (product name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.) was added and mixed to obtain the composition of Comparative Example 3.
• methylcellulose product name: Metolose (registered trademark), manufactured by Shin-Etsu Chemical Co., Ltd.
• a composition analysis was performed on the compact of Comparative Example 3 using ICP in the same manner as in Example 1, and the calcium concentration was found to be 0.1% by mass (oxide equivalent).
• Comparative Example 4 A latent heat storage material molded body of Comparative Example 4 was produced without using a compound corresponding to the calcium compound (B).
• ⁇ Moldability> Among the 10 samples, if the proportion of the samples with no problems in appearance such as cracks or chips was 70% or more, it was judged to have good moldability and pass, and if it was less than 70%, it was judged to have poor moldability and fail. For example, as shown in Table 1, in Example 1, of the 10 samples of the heat storage material molded body prepared above, 9 samples were not observed to have problems in appearance such as cracks or chips. Therefore, the proportion of the samples with no problems in appearance in the heat storage material molded body of Example 1 was 90%, and the moldability was good, resulting in a pass.
• the thermal storage material molded bodies of Examples 1 to 6 were able to achieve good results in terms of metal leakage, moldability, and crushing strength.
• metal leakage was confirmed in the molded body of Comparative Example 1, and the crushing strength was also low.
• Metal leakage was confirmed in the molded body of Comparative Example 2, and the moldability of Comparative Example 3 was poor, and metal leakage was confirmed in Comparative Example 4, and the crushing strength was also poor.
• ⁇ Heat storage measurement> The amount of heat storage was measured by TG-DSC (manufactured by TA Instruments, product name: SDT650).
• the cylindrical sample obtained in Example 1 was crushed in a mortar.
• the crushed sample was placed in an alumina sample pan, and the temperature was raised to 700°C at a temperature rise rate of 10°C/min under nitrogen flow of 20 ml/min, and the amount of heat storage (latent heat amount/absorbed heat amount) was measured (first time). After that, the temperature was lowered to 500°C at a temperature drop rate of 5°C/min, and the amount of heat release (latent heat amount/heat release amount) was measured (first time).
• the temperature was raised again to 700°C at a temperature rise rate of 10°C/min, and the amount of heat storage (latent heat amount/absorbed heat amount) was measured (second time). After that, the temperature was lowered to 500°C at a temperature drop rate of 5°C/min, and the amount of heat release (latent heat amount/heat release amount) was measured (second time). Furthermore, the same operation as the second time was repeated again to measure the amount of stored heat (amount of latent heat/amount of absorbed heat) and the amount of released heat (amount of latent heat/amount of generated heat) (third time). As an example, the results of Example 1 are shown in Table 2.
• the latent heat storage material molded body obtained in Example 1 did not show any decrease in the amount of heat stored or released, even when the measurement was repeated three times. In other words, it was confirmed that the latent heat storage material molded body obtained in the Example repeatedly functions as a heat storage body. Furthermore, the same results as in Example 1 were obtained for the latent heat storage material molded bodies obtained in Examples 2 to 6. On the other hand, for the molded bodies of Comparative Examples 1 to 4, the amount of heat stored and released decreased when the measurement was repeated three times.

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