Structural material, and method for manufacturing structural material

Abstract

To provide a structural material which has excellent heat storage property, and can secure a heat source and energy.SOLUTION: There is provided a structural material having a heat storage material in which particles containing silicon oxide as a main component are coated with a modifier containing a resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to structural materials and methods for manufacturing structural materials. [Background technology]

[0002] BACKGROUND ART Research has been conducted to create heat storage materials using geological materials in the local environment in order to secure a heat source and energy at night in environments where solar power generation is not available. As the heat storage material, for example, a heat storage material containing calcium oxide as a main component has been disclosed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-158696 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a structural material that has excellent heat storage properties and can secure a heat source and energy. [Means for solving the problem]

[0005] A first aspect of the present disclosure is a heat storage material in which particles containing silicon oxide as a main component are coated with a modifier containing a resin.

[0006] A second aspect of the present disclosure is the heat storage material according to the first aspect, which is a porous body in which the particles coated with the modifier are bonded together.

[0007] A third aspect of the present disclosure is the heat storage material according to the first or second aspect, wherein the resin is at least one of a polyamide-imide resin and a phenolic resin.

[0008] A fourth aspect of the present disclosure is the heat storage material according to the first or second aspect, wherein the particles are particles containing silicon oxide present in outer space as a main component.

[0009] A fifth aspect of the present disclosure is the heat storage material according to the first or second aspect, wherein the modifier contains a solvent.

[0010] A sixth aspect of the present disclosure is a method for producing a heat storage material, which comprises coating particles containing silicon oxide as a main component with a modifier containing a resin.

[0011] A seventh aspect of the present disclosure is a method for producing a heat storage material according to the fifth aspect, wherein the silicon oxide is particles containing silicon oxide present in outer space as a main component. [Effects of the Invention]

[0012] According to the present disclosure, a structural material can be provided that has excellent heat storage properties and can secure a heat source and energy. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 10 is an explanatory diagram of environmental conditions in a simulation evaluation of a heat storage material according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram showing the surface temperature of the moon when polyamide-imide resin is used in a simulation evaluation of a heat storage material according to an embodiment of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram showing the surface temperature of the moon when a phenolic resin is used in a simulation evaluation of a heat storage material according to an embodiment of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram showing the amount of heat from the surface of the moon when polyamide-imide resin is used in a simulation evaluation of a heat storage material according to an embodiment of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram showing the amount of heat from the surface of the moon when a phenolic resin is used in a simulation evaluation of a heat storage material according to an embodiment of the present disclosure. [Figure 6] 3A and 3B are diagrams of particles and a modifier before and after kneading in a method for producing a heat storage material according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a diagram of a permeability test piece mold used in a method for producing a heat storage material according to an embodiment of the present disclosure. [Figure 8] FIG. 1 is a diagram of a thermal storage material according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the embodiments are not limited by the following description and can be modified as appropriate within the scope of the present disclosure. Furthermore, in this specification, unless otherwise specified, the symbol "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0015] (heat storage material) The heat storage material of the present disclosure is a heat storage material in which particles containing silicon oxide as a main component are coated with a modifier containing a resin. The heat storage material of the present disclosure may further contain other components as necessary. Hereinafter, in this specification, particles containing silicon oxide as a main component and coated with a modifier containing a resin may be referred to as "coated particles."

[0016] The present inventors have conducted extensive research and have found that a heat storage material having excellent heat storage properties can be obtained by coating particles containing silicon oxide as a main component with a modifier containing a resin. The heat storage material according to one embodiment of the present invention can secure a heat source and energy even at night in an environment where solar power generation is unavailable. Here, the environment where solar power generation is unavailable is not particularly limited, but an example thereof is an environment such as on the surface of the moon.

[0017] On the surface of the moon, day and night alternate every two weeks, so it is important to secure a heat source and energy at night when solar power generation cannot be used. In the lunar environment, it is possible to utilize the regolith that is widely deposited on the surface of the moon. Regolith itself is primarily composed of silicon oxide, which has a relatively high heat storage capacity, but because regolith has many voids, it is not suitable as a heat storage material in its original form. The heat storage material according to one embodiment of the present invention has excellent heat storage properties even if it is made of particles with many voids, such as regolith, by coating it with a modifier containing a resin.

[0018] The heat storage material of the present disclosure may be in the form of particles, or may be in the form of a porous body in which particles coated with a modifier are bonded together. The porous body is formed by bonding the resins together using the resin contained in the modifier. That is, the heat storage material according to one embodiment of the present disclosure can be formed by coating particles with a resin having high heat storage properties and molding them at a heating temperature of less than 300°C, so there is no need to melt the particles at a high temperature exceeding 1,000°C.

[0019] Furthermore, in the porous body, the voids formed by bonding of the particles are preferably a vacuum, since the transfer of energy as heat does not occur in the voids, thereby further improving the heat insulating performance.

[0020] <<Particle>> The particles are particles whose main component is silicon oxide, and may contain other components as necessary. "Mainly composed of silicon oxide" means that the particles have the highest content of silicon oxide relative to the entire particle, although they may contain impurities other than silicon oxide. By having the particles whose main component is silicon oxide, which has high heat storage capacity, they can be used as a heat storage material with even better heat storage capacity. Furthermore, the particles are preferably particles whose main component is silicon oxide, which exists in outer space.

[0021] The silicon oxide is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include silicon monoxide (SiO) and silicon dioxide (SiO2).

[0022] The content of silicon oxide is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 20% by mass or more, more preferably 45% by mass or more, based on the total amount of the particles.

[0023] The other components are not particularly limited and can be selected appropriately depending on the purpose. Examples include titanium dioxide (TiO), aluminum oxide (AlO), iron (II) oxide (FeO), iron (III) oxide (FeO), magnesium oxide (MgO), calcium oxide (CaO), sodium oxide (NaO), and potassium oxide (KO).

[0024] The density of silicon oxide is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 1,000 kg / m 3 More than 1,000 kg / m is preferable. 3 More than 3,000kg / m 3 Less than 2,000 kg / m is more preferable. 3 More than 2,500kg / m 3 The following are particularly preferred:

[0025] The thermal conductivity of silicon oxide is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1.0 W / (m·K) or higher, and more preferably 1.0 W / (m·K) to 5.0 W / (m·K). A thermal conductivity of 1.0 W / (m·K) or higher allows more efficient extraction of energy as heat from the heat storage material, allowing more energy to be released at night.

[0026] The specific heat of silicon oxide is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 500 J / (kg·K) or more, and more preferably 1,000 J / (kg·K) to 2,000 J / (kg·K). If the specific heat is 500 J / (kg·K) or more, more energy can be released at night.

[0027] The average particle size of the particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 μm or more and 250 μm or less. The average particle size can be measured, for example, using a laser diffraction particle size distribution analyzer (LA-950V2 manufactured by Horiba, Ltd.), and the obtained median diameter (particle size corresponding to 50% of the cumulative distribution, 50% particle size) can be used as the average particle size.

[0028] <<Modifier>> The modifier contains a resin and may further contain other components such as a solvent as necessary. By coating the particles with a modifier containing a resin, the specific heat and thermal conductivity of the coated particles themselves can be improved by the effect of the resin.

[0029] The resin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include polyamide resin, polyimide resin, polyamideimide resin, phenol resin, etc. These may be used alone or in combination of two or more. Among these, polyamideimide resin and phenol resin are preferred. When the resin is a phenol resin, a solvent may not be included.

[0030] The density of the resin is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 500 kg / m 3 More than 500 kg / m 3 More than 2,000kg / m 3 Less than 1,000 kg / m is more preferable. 3 More than 1,500kg / m 3 The following are particularly preferred:

[0031] There are no particular restrictions on the thermal conductivity of the resin and it can be selected appropriately depending on the purpose, but it is preferably 0.1 W / (m·K) or higher, and more preferably 0.1 W / (m·K) to 0.5 W / (m·K). If the thermal conductivity is 0.1 W / (m·K) or higher, energy can be extracted as heat more efficiently from the heat storage material, allowing more energy to be released at night.

[0032] The specific heat of the resin is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 500 J / (kg·K) or more, and more preferably 1,000 J / (kg·K) to 2,000 J / (kg·K). If the specific heat is 500 J / (kg·K) or more, more energy can be released at night.

[0033] The content of the resin is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 5% by mass or more and 40% by mass or less based on the total amount of the modifier.

[0034] The following explains how to predict the thermal properties of particles coated with a modifier. Table 1 shows the results of calculations using polyamide-imide resin (hereinafter sometimes referred to as "PAI resin") and phenolic resin as the resins contained in the modifier. [Table 1]

[0035] As is clear from the calculation results shown in Table 1, the specific heat and thermal conductivity of the heat storage material are high for both polyamide-imide resin and phenolic resin. Furthermore, as the thickness of the resin increases, the specific heat and thermal conductivity also increase.

[0036] Furthermore, a simulation evaluation in a lunar environment is performed on the heat storage material according to an embodiment of the present disclosure. In the simulation evaluation, calculations are performed assuming the case of a normal particle (regolith) state and the case of a heat storage material coated with polyamide-imide resin or phenolic resin under the environmental conditions shown in Fig. 1. The results are shown in Figs. 2 to 5. As shown in Figures 2 and 3, it can be seen that both polyamide-imide resin and phenolic resin can increase the surface temperature of the moon at night when the film thickness is 1 μm to 9 μm. Also, as shown in Figures 4 and 5, it can be seen that both polyamide-imide resin and phenolic resin can increase the amount of heat from the moon's surface when the film thickness is 1 μm to 9 μm.

[0037] The thickness of the modifier in the particles coated with the modifier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 μm or more, more preferably 5 μm or more.

[0038] The solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include water, ethyl lactate, propylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N,N-dimethylformamide, methyl ethyl ketone, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether, toluene, xylene, etc. These solvents may be used alone or in combination of two or more.

[0039] The content of the solvent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 40% by mass or more and 95% by mass or less based on the total amount of the modifier.

[0040] Examples of other components include plasticizers, surface lubricants, leveling agents, softeners, antioxidants, light stabilizers, ultraviolet absorbers, surfactants, and antistatic agents.

[0041] (Method of manufacturing heat storage material) The method for producing a heat storage material according to the present disclosure includes a step of coating particles containing silicon oxide as a main component with a modifier containing a resin. The method for producing a heat storage material according to the present disclosure may further include other steps as necessary.

[0042] The manufacturing apparatus used in the method for manufacturing a heat storage material of the present disclosure is not particularly limited and can be appropriately selected depending on the purpose. For example, a small device mainly composed of a screw can be used to knead the particles and the modifier, thereby coating the particles with the modifier. Since the small device can be operated only by motor drive, it is energy-saving and low-cost. Note that in an environment such as the lunar surface, it is preferable to use particles whose main component is silicon oxide, which exists in outer space as silicon oxide. This means that the only material transported from Earth is the modifier, minimizing increases in transportation costs.

[0043] The temperature at which the particles and modifier are kneaded is not particularly limited and can be selected appropriately depending on the purpose, but particles at 75°C or higher can be mixed with resin at room temperature and kneaded at room temperature.

[0044] The time for kneading the particles and modifier is not particularly limited and can be appropriately selected depending on the purpose, but for example, stirring for 30 seconds can be carried out a total of four times.

[0045] The other steps are not particularly limited and can be selected appropriately depending on the purpose, but examples include a step of heat-molding particles coated with a modifier. This allows the heat storage material to be shaped into a porous body in which particles coated with a modifier are bonded. The heating temperature can be set to 60°C or higher and 270°C or lower, taking the glass transition point or softening point as a guide depending on the properties of the resin. The heating time can be adjusted appropriately depending on the type of resin and the size of the porous body. [Example]

[0046] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0047] Example 1 800 g of Toyoura standard sand (TKA-1) as particles and 53.3 g of a modifier containing polyimideamide resin (HPC-5000 (Resonac Corporation), non-volatile content: 30.1%, viscosity (30°C, B-type viscometer): 2.72 Pa·s) as resin were placed in a container as shown in Figure 6, and the mixture was kneaded by stirring for 30 seconds four times. The kneaded mixture was heat-molded at 270°C for 60 minutes using a permeability test piece mold as shown in Figure 7 to obtain a heat storage material. The obtained heat storage material is shown in Figure 8.

[0048] Example 2 800 g of Toyoura standard sand (TKA-1) as particles and 57.1 g of a modifier containing polyimideamide resin (HPC-1000 (Resonac Corporation), non-volatile content: 28.0%, viscosity (25°C, B-type viscometer): 3.39 Pa·s) as resin were placed in a container as shown in Figure 6, and the mixture was kneaded by stirring for 30 seconds four times. The kneaded mixture was heat-molded at 270°C for 60 minutes using a permeability test piece mold as shown in Figure 7 to obtain a heat storage material. The obtained heat storage material is shown in Figure 8.

[0049] Example 3 10,000 g of Toyoura standard sand (TKA-1) as particles, 200 g of phenolic resin (MS-928) as resin, 30 g of hexamethylenetetramine as hardener, and 240 g of modifier containing 10 g of calcium stearate as lubricant were placed in a container as shown in Figure 6, and the mixture was stirred for 50 seconds to coat the particles with the modifier. The hardener was then dispersed, cooled, and the lubricant was dispersed. The mixture was heat-molded at 270°C for 60 minutes using a permeability test piece mold as shown in Figure 7 to obtain a heat storage material. The obtained heat storage material is shown in Figure 8.

[0050] The heat storage materials obtained in Examples 1 to 3 were measured for ignition loss (at 900°C for 40 minutes), ignition loss of the molded product (at 900°C for 40 minutes), weight, thickness, and transverse rupture strength. The results are shown in Table 2. The compressive strength (maximum stress) was also measured for Examples 1 and 2. The results are shown in Table 3.

[0051] [Table 2]

[0052] [Table 3]

[0053] As shown in Tables 2 and 3, the heat storage material of the present disclosure is excellent in compressive strength and bending stress, and can be used as a structural material.

Claims

1. A structural material comprising a heat storage material in which particles primarily composed of silicon oxide are coated with a modifier containing a resin.

2. 10. The structural material of claim 1, wherein said particles coated with said modifier are a bonded porous body.

3. 3. The structural material according to claim 1, wherein the resin is at least one of a polyamide-imide resin and a phenolic resin.

4. 3. The structural material according to claim 1, wherein the particles are particles containing silicon oxide, which exists in outer space, as a main component.

5. 3. The structural material of claim 1, wherein the modifier comprises a solvent.

6. A method for manufacturing a structural material, characterized in that particles mainly composed of silicon oxide are coated with a modifier containing a resin.

7. 7. The method for manufacturing a structural material according to claim 6, wherein the silicon oxide is a particle whose main component is silicon oxide present in outer space.

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