Method for producing inorganic material, apparatus for producing inorganic material, and structure

Abstract

To provide a method for producing an inorganic material which can be pyrolytically decomposed at a lower temperature than before.SOLUTION: A method for producing an inorganic material according to the present disclosure comprises a contact step S1, an atmosphere control step S2, and a heating step S3. In the contact step S1, a composite material 101 which comprises an organic material 106 that is composed of an organic material and an inorganic material 105 that is composed of an inorganic material is brought into contact with a decomposition promoting component 102 which promotes thermal decomposition of the organic material 106 and contains copper as a main component in terms of the mass ratio among the transition metal elements contained therein. In the atmosphere control step S2, the atmosphere of a space in which a mixture 107 that contains the composite material 101 and the decomposition promoting component 102 is present is controlled to be a gas 103 that contains oxygen. In the heating step S3, the composite material 101 and the decomposition promoting component 102 are heated in an oxidizing atmosphere in a state in which they are in contact with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing an inorganic material, an apparatus for producing an inorganic material, and a structure. [Background technology]

[0002] In response to environmental regulations and energy conservation, efforts are being made to reduce the weight of aircraft, railway vehicles, automobiles, etc. In particular, composite materials such as fiber-reinforced resins containing inorganic materials such as inorganic fibers and fillers are being used in components to reduce weight and improve rigidity. However, composite materials contain multiple materials, and there is a demand for separating the inorganic materials in order to recycle the composite materials.

[0003] The abstract of Patent Document 1 states that "when producing fuel from a treatment object containing a polymeric organic matter, the method includes a step of contacting the treatment object with a catalyst containing an oxide semiconductor and a transition metal element, and further includes a step of heating the treatment object that has been contacted with the catalyst containing the oxide semiconductor and the transition metal element in an atmosphere containing hydrogen and oxygen." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-55446 Summary of the Invention [Problem to be solved by the invention]

[0005] Paragraph 0033 of Patent Document 1 describes that the combination of an oxide semiconductor and a transition metal element promotes the oxidative decomposition reaction and allows the treatment temperature to be lowered. Although details will be described later with reference to Examples, the present inventors have found that the decomposition-promoting component that promotes the thermal decomposition of organic materials, which contains copper as a main component by mass ratio among the transition metal elements contained therein, can lower the thermal decomposition temperature compared to the case of using other transition metal elements. The problem to be solved by the present disclosure is to provide a method for producing an inorganic material that can be thermally decomposed at a lower temperature than conventional methods, an apparatus for producing an inorganic material, and a structure. [Means for solving the problem]

[0006] The method for producing an inorganic material according to the present disclosure includes a heating step of heating a composite material containing an organic material composed of an organic substance and an inorganic material composed of an inorganic substance in contact with a decomposition-promoting component that promotes thermal decomposition of the organic material and contains copper as a main component by mass ratio among the transition metal elements contained in the composite material in an oxidizing atmosphere. Other solutions will be described later in the description of the embodiment of the invention. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a method for producing an inorganic material that can be thermally decomposed at a lower temperature than conventional methods, an apparatus for producing an inorganic material, and a structure. [Brief description of the drawings]

[0008] [Figure 1] 1 is a flowchart illustrating a method for producing an inorganic material according to the present disclosure. [Diagram 2] 10 is a flowchart showing a method for producing an inorganic material according to another embodiment. [Diagram 3] 10 is a flowchart showing a method for producing an inorganic material according to another embodiment. [Figure 4] FIG. 2 is a perspective view showing the inside of an inorganic material manufacturing apparatus according to the present disclosure. [Diagram 5] FIG. 4 is a perspective view showing the inside of an inorganic material manufacturing apparatus according to another embodiment. [Figure 6] FIG. 1 is a perspective view of a structure of the present disclosure. [Figure 7] FIG. 13 is a perspective view of a structure according to another embodiment. [Figure 8] 1 is a graph showing the decomposition behavior of each decomposition-promoting component. [Figure 9] 1 is a graph showing the decomposition behavior of each decomposition-promoting component according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a form for carrying out the present disclosure (referred to as an embodiment) will be described with reference to the drawings. In the following description of one embodiment, other embodiments applicable to the one embodiment will also be described as appropriate. The present disclosure is not limited to the following one embodiment, and different embodiments can be combined with each other or modified as desired without significantly impairing the effects of the present disclosure. In addition, the same symbols will be used for the same members, and duplicate descriptions will be omitted. Furthermore, the same names will be used for members having the same functions. The contents shown are merely schematic, and for the sake of illustration, changes may be made from the actual configuration within a range that does not significantly impair the effects of the present disclosure, and some members may be omitted or modified between drawings. In addition, the same embodiment does not necessarily need to have all the configurations.

[0010] 1 is a flowchart showing a method for producing an inorganic material 105 according to the present disclosure (hereinafter, simply referred to as the "production method according to the present disclosure") The production method shown in FIG. 1 can be carried out, for example, by a production apparatus 200 shown in FIG. 4, which will be described later.

[0011] The manufacturing method of the present disclosure is a method for manufacturing an inorganic material 105 from a composite material 101 containing an inorganic material 105 and an organic material 106. As the composite material 101, for example, so-called "waste plastic" obtained from waste of home appliances (washing and drying machines, refrigerators, vacuum cleaners, water heaters, etc.), aircraft, railroad cars, automobiles, industrial products, etc. can be used. Therefore, the manufacturing method of the present disclosure can also be said to be a method for recycling the composite material 101 and the inorganic material 105. The manufactured inorganic material 105 can be reused as a part of a new composite material 101, for example, as a recycled material.

[0012] The inorganic material 105 in the composite material 101 from which the inorganic material 105 is separated (recovered) may be a virgin material or a recycled material. The recycled material may be, for example, an inorganic material 105 manufactured by the manufacturing method of the present disclosure. Hereinafter, when simply referring to "inorganic material 105," the inorganic material 105 may be either a virgin material or a recycled material unless otherwise specified.

[0013] In the manufacturing method of the present disclosure, the organic material 106 in the composite material 101 is thermally decomposed at a lower temperature than in the past (for example, 440° C. or lower, preferably 400° C. or lower). In the present disclosure, the thermal decomposition (thermal decomposition reaction) of the organic material 106 is carried out in an oxidizing atmosphere, and therefore can also be called oxidative decomposition. By carrying out the thermal decomposition at a lower temperature than in the past, it is possible to suppress thermal deterioration of the inorganic material 105 contained together with the organic material 106, and to suppress changes in the physical properties of the inorganic material 105, such as a decrease in strength. This makes it possible to manufacture a new composite material 101 that is comparable in physical properties to the composite material 101 that uses the inorganic material 105 as a virgin material.

[0014] The inorganic material 105 contained in the composite material 101 is composed of an inorganic substance. Examples of inorganic substances include inorganic fibers, inorganic fillers, and metals. Examples of inorganic fibers include glass fibers, asbestos fibers, carbon fibers, silica fibers, silica-alumina fibers, alumina fibers, zirconia fibers, potassium titanate fibers, Tyranno fibers, silicon carbide fibers, and metal fibers. These fibers can be used alone or in combination of two or more. These fibers are used in the form of continuous fibers, long fibers, short fibers, chopped fibers, and the like, and in the form of unidirectional materials, plain weaves, nonwoven fabrics, and the like. However, the fiber shape or fiber state is not limited to these fiber shapes or fiber states.

[0015] Examples of inorganic fillers include powders such as fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, aluminum nitride, boron nitride, beryllia, zircon, fosterite, stearite, spirel, mullite, titania, etc., and beads obtained by spheroidizing these. There is no limitation on the shape of the inorganic filler, and any shape such as spheres or flakes may be used.

[0016] Examples of metals contained in the inorganic material 105 include steel, aluminum, aluminum alloys, magnesium alloys, titanium alloys, etc. Furthermore, there is no limitation on the shape of the metal, and any shape such as plate-like, spherical, or scaly may be used.

[0017] Of these, the inorganic material preferably contains at least one of carbon fiber and glass fiber. These are often used to improve the strength of the composite material 101, for example. For this reason, the composite material 101 has high strength, but due to the high strength, it is difficult to remove (separate) the inorganic material 105 from the composite material 101, for example, by crushing the composite material 101. However, according to the manufacturing method of the present disclosure, as described above, the thermal decomposition temperature of the organic material 106 can be lowered than before. For this reason, the organic material 106 can be easily thermally decomposed, and the inorganic material 105 can be removed (manufactured) from the composite material 101.

[0018] The organic material 106 is made of an organic substance, and the organic substance includes a resin such as a thermosetting resin or a thermoplastic resin. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, a silicone resin, a polyimide resin, a bismaleimide resin, and a thermosetting urethane resin. Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylnitrile butadiene styrene, polyvinyl chloride, methacrylic resin, polyethylene terephthalate, polybutylene terephthalate, polyvinyl alcohol, polyamide, and polycarbonate. One type of resin may be used alone, or two or more types may be used in any ratio and proportion.

[0019] Among them, the organic matter preferably contains a thermosetting resin. Since a thermosetting resin is hardened by heating, it is difficult to melt the organic material 106, and it is difficult to separate the inorganic material 105 contained together with the organic material 106 from the organic material 106. However, according to the manufacturing method of the present disclosure, the thermal decomposition temperature of the organic material 106 can be lowered compared to the conventional method, so that the organic material 106 can be easily thermally decomposed, and the inorganic material 105 can be taken out (manufactured) from the composite material 101.

[0020] The composite material 101 may contain additives such as flame retardants, antioxidants, light stabilizers, dispersants, lubricants, plasticizers, antistatic agents, pigments, dyes, etc., as necessary.

[0021] The manufacturing method of the present disclosure includes a contact step S1, an atmosphere control step S2, and a heating step S3. The contact step S1 is a step of contacting a composite material 101 with a decomposition-promoting component 102. In the present disclosure, mixing is exemplified as an example of contact. Thus, a mixture 107 containing the composite material 101 and the decomposition-promoting component 102 is produced by contacting the composite material 101 with the decomposition-promoting component 102. Note that "mixing" does not need to be to the extent that the composite material 101 and the decomposition-promoting component 102 are completely and uniformly mixed as a whole, and may be in a state in which the composite material 101 and the decomposition-promoting component 102 coexist in the same reaction tank 1 (FIG. 4), for example.

[0022] The manner of contact is not particularly limited. For example, the composite material 101 crushed into a rod shape having a length of about 1 mm to 10 mm can be mixed with the decomposition-promoting component 102 in a powder form (for example, a particle size of 10 μm to 500 μm based on a laser diffraction scattering method). The mixing can be performed, for example, by putting the composite material 101 and the decomposition-promoting component 102 into the reaction vessel 1 (FIG. 4; a container or the like). Alternatively, the decomposition-promoting component 102 may be attached to a structure such as the wall surface of the reaction vessel 1 or the stirring mechanism 5 (FIG. 4), and the composite material 101 may be brought into contact with the attached decomposition-promoting component 102.

[0023] The decomposition-promoting component 102 promotes the thermal decomposition of the organic material 106, and contains copper as a main component (preferably more than 50 mass%, more preferably 100 mass%) by mass ratio among the transition metal elements contained in the decomposition-promoting component 102. The decomposition-promoting component 102 includes components that do not change during the thermal decomposition of the organic material 106 (e.g., copper oxide (II) etc.) and components that change (e.g., copper oxide (I), organic copper etc.). Of these, the decomposition-promoting component 102 that does not change during the thermal decomposition can be referred to as, for example, a "catalyst."

[0024] The decomposition-promoting component 102 contains copper. The copper referred to here may be copper alone or a copper compound. When the decomposition-promoting component 102 contains copper, the copper in the decomposition-promoting component 102 is oxidized to generate copper oxide (II) when the decomposition-promoting component 102 is heated in an oxidizing atmosphere. However, when the decomposition-promoting component 102 contains the above-mentioned copper oxide (II), the copper oxide (II) contained from the beginning usually does not change. When the copper oxide (II) is heated, thermal excitation occurs inside the copper oxide (II), and holes and electrons are generated. The holes, due to their oxidizing power, steal electrons from the organic matter present around the copper oxide (II), thereby oxidizing and decomposing the organic matter. In addition, the electrons generated by the thermal excitation are transferred to oxygen contained in the atmosphere, thereby generating active oxygen. The active oxygen promotes the oxidative decomposition of the organic matter, which also leads to the oxidative decomposition of the organic matter.

[0025] It has been revealed that by using the decomposition-promoting component 102 capable of generating mainly copper oxide (II) during thermal decomposition among various oxides, thermal decomposition can be performed at a low temperature (for example, 440°C or less, preferably 400°C or less). Unlike other oxides, the mechanism by which copper oxide (II) can oxidatively decompose organic matter at low temperatures is not necessarily clear. However, according to the inventor's investigation, it is believed to be due to the high activity (reactivity) of copper oxide (II), the valence of copper contained in copper oxide (II), the ease of generating holes and electrons in copper oxide (II), etc. Note that the mechanism is merely speculation and is not limited to this content, and there may be other reasons.

[0026] As described above, the decomposition-promoting component 102 contains copper as a main component. The term "main component" here means that the transition metal element contained in the decomposition-promoting component 102 is the most abundant in terms of mass ratio (for example, when there are two kinds of transition metal elements, copper is more than 50 mass%). The decomposition-promoting component 102 preferably contains at least one of copper alone or a compound containing copper as a main component (hereinafter referred to as copper compound). As the copper compound, for example, copper oxide, organic copper compound, copper alloy, etc. can be obtained. As the copper oxide, copper (I) oxide (Cu2O) and copper (II) oxide (CuO) can be mentioned. As the organic copper compound, copper acetate (II) and copper acetylacetonate (II) can be mentioned. Only one type of copper compound may be used, or two or more types may be used at any ratio and proportion.

[0027] In particular, it is preferable that the decomposition-promoting component 102 contains elemental copper. This allows the entire elemental copper to be oxidized to copper oxide (II), and increases the amount of copper oxide (II) involved in the thermal decomposition of the organic material 106. As a result, the amount of organic material 106 to be thermally decomposed can be increased, and the processing efficiency of the composite material 101 can be improved.

[0028] In addition, it is preferable that the decomposition-promoting component 102 contains at least one of copper oxide (I) and copper oxide (II). Since copper is easily naturally oxidized by oxygen, even copper oxide that can be naturally oxidized, such as copper oxide (II), can be used as the decomposition-promoting component.

[0029] In addition, it is preferable that the decomposition-promoting component 102 contains an organic copper compound. Since the organic copper compound has a carbon skeleton, it has excellent affinity with the organic material 106. Therefore, the organic copper compound easily acts on the organic material 106, and can easily promote the thermal decomposition of the organic material 106.

[0030] It is preferable that the decomposition-promoting component 102 does not contain an oxide semiconductor (except for copper oxide). Copper oxide here refers to copper oxide (II) and copper oxide (I). Copper oxide is an oxide semiconductor, and by using copper oxide among the oxide semiconductors, the organic material 106 can be thermally decomposed at a lower temperature than when other oxide semiconductors are used. Therefore, by not containing any oxide semiconductor other than copper oxide, the organic material 106 can be thermally decomposed at a lower temperature. However, although it is preferable that the decomposition-promoting component 102 does not contain any oxide semiconductor other than copper oxide, the organic material 106 may be supplementarily decomposed with an oxide semiconductor other than copper oxide.

[0031] Specifically, the decomposition-promoting component 102 may supplementarily contain at least one of a compound that is a thermally stable oxide semiconductor and a compound that produces a thermally stable oxide semiconductor when heated with the organic material 106. Examples of such compounds include at least one of CaO, MnO, ZrO2, WO2, TiO2, V2O5, Cr2O3, NiO, Fe2O3, Fe3O4, ZnO, CoO, and Co3O4.

[0032] It is preferable that the decomposition-promoting component 102 does not contain any transition metal elements (except copper). By using copper among the transition metals, copper oxide (II) can be generated when heated in an oxidizing atmosphere. As described above, the copper oxide (II) can thermally decompose the organic material 106 at a lower temperature than when other transition metals are used. Therefore, by not including any transition metal elements other than copper, the organic material 106 can be thermally decomposed at a lower temperature. However, although it is preferable that the component does not include any transition metal elements other than copper, the component may additionally include transition metal elements other than copper.

[0033] The content of the decomposition-promoting component 102 relative to the organic material 106 is preferably 50% by mass or more. By setting the amount of the decomposition-promoting component 102 used within this range, the organic material 106 can be thermally decomposed. However, the content of the decomposition-promoting component 102 can also be appropriately adjusted depending on the shapes of the organic material 106 and the decomposition-promoting component 102, etc. There is no particular upper limit to the content, and it may be appropriately determined depending on the production cost of the inorganic material 105, the internal volume of the reaction tank 1 (FIG. 4), etc.

[0034] The decomposition-promoting component 102 preferably has a particulate shape (for example, powder shape). By having such a shape, the contact area with the organic material 106 can be increased, and the thermal decomposition of the organic material 106 that occurs at the contact portion between the decomposition-promoting component 102 and the organic material 106 can be promoted.

[0035] The atmosphere control step S2 (FIG. 1) is a step of controlling the atmosphere at the contact portion where the composite material 101 and the decomposition-promoting component 102 are brought into contact with each other. In the example of the present disclosure, for example, the atmosphere of the space in which the mixture 107 obtained in the contact step S1 exists (the atmosphere of the internal space of the reaction tank 1 (FIG. 4)) is controlled. In the atmosphere control step S2, the atmosphere of the space in which the mixture 107 is placed is controlled to a gas 103 containing oxygen. That is, the mixture 107 exists in the gas 103. The gas 103 is, for example, air, oxygen gas, etc.

[0036] In addition, when at least one of the composite material 101 and the decomposition-promoting component 102 contains a component that generates oxygen during the heating step S3, the atmosphere control step S2 may not be included. When the atmosphere control step S2 is not included, the copper in the decomposition-promoting component 102 is oxidized by oxygen generated from at least one of the composite material 101 and the decomposition-promoting component 102 during the heating step S3. As a result, the heating step S3 is performed in which the composite material 101 and the decomposition-promoting component 102 are heated in an oxidizing atmosphere while being in contact with each other.

[0037] The heating step S3 is a step of heating the composite material 101 and the decomposition-promoting component 102 in contact with each other in an oxidizing atmosphere. In the example of the present disclosure, the heating step S3 is a step of heating the mixture 107 present in the gas 103.

[0038] The heating step S3 is performed by heating to a temperature that thermally decomposes the organic material 106. By heating to this temperature, the organic material 106 can be thermally decomposed.

[0039] However, the heating step S3 is preferably performed by heating at a temperature of, for example, 440° C. or less, preferably 420° C. or less, and more preferably 400° C. or less, which is a temperature at which the organic material 106 is thermally decomposed. For example, by heating at a temperature of 440° C. or less, preferably 420° C. or less, and more preferably 400° C. or less, it is possible to suppress thermal deterioration of the inorganic material 105, which has a significant effect when the recycled inorganic material 105 is reused. In addition, the heating step S3 is preferably performed by heating at a temperature of, for example, 200° C. or more, preferably 250° C. or more, more preferably 300° C. or more, and particularly preferably 350° C. or more.

[0040] The heating time in the heating step S3 is not particularly limited, but may be, for example, from 5 minutes to 1 hour.

[0041] The solid organic material 106 is converted into exhaust gas 104 by the thermal decomposition of the organic material 106. The exhaust gas 104 contains, for example, carbon dioxide, and is appropriately exhausted to the outside. Meanwhile, the inorganic material 105 contained in the composite material 101 remains in the reaction tank 1 (FIG. 4). Therefore, the inorganic material 105 can be extracted from the reaction tank 1.

[0042] The heating step S3 is preferably performed while at least one of the composite material 101 and the decomposition-promoting component 102 is subjected to at least one of vibration and stirring in a state in which the composite material 101 and the decomposition-promoting component 102 are in contact (e.g. mixed). By performing the heating step S3 in this manner, the contact opportunity between the composite material 101 and the decomposition-promoting component 102 can be increased, and the thermal decomposition of the organic material 106 can be promoted, compared to a case in which the heating step S3 is performed while the composite material 101 is left stationary.

[0043] The heating step S3 is preferably carried out using the reaction vessel 1 (FIG. 4) used in the contacting step S1. By carrying out the contacting step S1 and the heating step S3 using the same reaction vessel 1, the thermal decomposition of the organic material 106 can be carried out continuously.

[0044] Fig. 2 is a flow chart showing a method for producing an inorganic material 105 according to another embodiment. In the embodiment shown in Fig. 2, unlike the embodiment shown in Fig. 1, a contact step S1 is performed after an atmosphere control step S2. Specifically, for example, the atmosphere in the internal space of a reaction vessel 1 (Fig. 4) in which a decomposition-promoting component 102 is placed is composed of a gas 103 containing oxygen (atmosphere control step S2). Therefore, the decomposition-promoting component 102 is present in the gas 103. Then, by further placing a composite material 101 in the reaction vessel 1 in this state, the atmosphere of the mixture 107 is composed of the gas 103 (contact step S1).

[0045] The embodiment shown in FIG. 2 also makes it possible to oxidatively decompose the organic material 106 at a lower temperature than before.

[0046] FIG. 3 is a flow chart showing a method for producing an inorganic material 105 according to another embodiment. In the embodiment shown in FIG. 3, the heating step S3 includes a preheating step S31 and a main heating step S32 in the embodiment shown in FIG. 2. After the atmosphere control step S2, the preheating step S31, which is a part of the heating step S3, is performed. The preheating step S31 is a step of increasing the temperature of the decomposition-promoting component 102 to a heating temperature in the main heating step S32 described below. After the temperature of the decomposition-promoting component 102 is increased to a desired temperature, the composite material 101 is put into a reaction tank, and the mixture 107 is produced (contact step S1). Then, the main heating step S32 is performed on the mixture 107. The main heating step S32 can be performed in the same manner as the heating step S3 described with reference to FIG. 1 and the like.

[0047] 3 also makes it possible to oxidatively decompose the organic material 106 at a lower temperature than in the past. Furthermore, since the composite material 101 is brought into contact with the preheated decomposition-promoting component 102, it is possible to shorten the time from when the composite material 101 is brought into contact with the decomposition-promoting component 102 until it is heated to a temperature at which it can be thermally decomposed. This makes it possible to shorten the processing time for the composite material 101.

[0048] FIG. 4 is a perspective view showing the inside of a manufacturing apparatus 200 for the inorganic material 105 (FIG. 1) of the present disclosure. The manufacturing apparatus 200 includes a reaction tank 1, a heating mechanism 2, an air supply port 3, an exhaust port 4, and a stirring mechanism 5. The reaction tank 1 contains a composite material 101 and a decomposition-promoting component 102. In the example shown in FIG. 4, the composite material 101 broken (crushed) into a long and thin rod shape is embedded in the powdered decomposition-promoting component 102. The reaction tank 1 is, for example, a hollow tank. The heating mechanism 2 heats the composite material 101 and the decomposition-promoting component 102 inside the reaction tank 1. The heating mechanism 2 is provided at the bottom of the reaction tank 1 and heats the composite material 101 and the decomposition-promoting component 102 from the bottom of the reaction tank 1. The heating mechanism 2 is, for example, an electric heating wire, a boiler, or the like.

[0049] The air supply port 3 (air supply pipe) supplies oxygen-containing gas 103 to the inside of the reaction tank 1. The exhaust port 4 (exhaust pipe) exhausts gas generated inside the reaction tank 1 from the reaction tank 1 as exhaust gas 104. The gas exhausted from the exhaust port 4 contains gas (e.g., carbon dioxide, water vapor, etc.) generated by thermal decomposition of the organic material 106. By exhausting the organic material 106 from the reaction tank 1 as a gas, the inorganic material 105 remains inside the reaction tank 1, making it easier to remove the inorganic material 105. The air supply port 3 and the exhaust port 4 are provided at the top of the reaction tank 1.

[0050] The stirring mechanism 5 stirs the composite material 101 and the decomposition-promoting component 102 inside the reaction tank 1. By providing the stirring mechanism 5, the contact opportunity between the composite material 101 and the decomposition-promoting component 102 is increased compared to the case where the material is left to react at rest, and the thermal decomposition of the organic material 106 generated at the contact portion between the composite material 101 and the decomposition-promoting component 102 can be promoted. The stirring mechanism 5 is, for example, a stirring blade, and in the illustrated example, the stirring blade is embedded in the powdered decomposition-promoting component 102.

[0051] As described above, inside the reaction tank 1, the composite material 101 and the decomposition-promoting component 102 come into contact with each other. Then, the gas 103 containing oxygen is supplied to the inside of the reaction tank 1 through the air supply port 3. Furthermore, the composite material 101 and the decomposition-promoting component 102 present inside the reaction tank 1 are heated by the heating mechanism 2. With these, the manufacturing method of the present disclosure (for example, FIG. 1) can be performed. Furthermore, the exhaust gas 104 generated by the decomposition reaction is exhausted from the reaction tank 1 through the exhaust port 4. The inorganic material 105 remaining inside the reaction tank 1 due to the thermal decomposition of the organic material 106 can be taken out, for example, through an upper opening of the reaction tank 1 using any jig (not shown). The removal can be performed, for example, after the supply of the gas 103 and the driving of the stirring mechanism 5 are stopped.

[0052] 5 is a perspective view showing the inside of a manufacturing apparatus 200 for the inorganic material 105 according to another embodiment. The manufacturing apparatus 200 shown in FIG. 5 further includes a recovery mechanism 6 in addition to the manufacturing apparatus 200 shown in FIG. 4. The recovery mechanism 6 recovers the inorganic material 105 obtained by thermal decomposition of the organic material 106 in the composite material 101 from inside the reaction tank 1. By providing the recovery mechanism 6, it becomes easier to recover the inorganic material 105 from inside the reaction tank 1.

[0053] In the example of the present disclosure, the recovery mechanism 6 is an outlet (extraction pipe) provided on the lower side of the reaction vessel 1. The inorganic material 105 can be recovered by separating it from the decomposition-promoting component 102 by utilizing differences in specific gravity, shape, etc., between the inorganic material 105 and the decomposition-promoting component 102. The outlet is preferably provided in a portion close to the bottom surface of the reaction vessel 1.

[0054] The manufacturing method of the present disclosure using the manufacturing apparatus 200 shown in Fig. 5 can be continuously performed. Specifically, for example, the inorganic material 105 is produced by thermally decomposing the organic material 106 inside the reaction tank 1 by the manufacturing method of the present disclosure. After production, the supply of the gas 103 and the driving of the stirring mechanism 5 are stopped, and the recovery mechanism 6 recovers the inorganic material 105. After the recovery, an optional transport mechanism (not shown) supplies the composite material 101 and the decomposition-promoting component 102 into the inside of the reaction tank 1 through, for example, a raw material supply port (not shown) of the reaction tank 1. Then, the manufacturing method of the present disclosure is performed again.

[0055] Fig. 6 is a perspective view of a structure 110 according to the present disclosure. Fig. 6 illustrates a member 112 provided in the structure 110, and in the example of Fig. 6, the member 112 is a plate material. The member 112 is made of a composite material 111. The composite material 111 is a newly manufactured composite material using an inorganic material 105 manufactured by the manufacturing method shown in Fig. 1 and the like, for example.

[0056] The structure 110 is any structure, such as a railroad car, a ship, an aircraft, an automobile, a wind power generator, a unit bath, a septic tank, a printed circuit board, a playground equipment, or skis, and the member 112 can be used as any member constituting the structure 110. For example, the member 112 can be used as a blade in a wind power generator, a frame or window frame for a railroad car, a portion from which a stator winding that constitutes a motor is taken out, a portion from which a permanent magnet that constitutes a rotor is taken out, a component of an inverter, or the like.

[0057] The member 112 includes an inorganic material 105 (FIG. 1) that is manufactured by at least a heating step S3 (FIG. 1) in which the composite material 101 (FIG. 1) and the decomposition-promoting component 102 (FIG. 1) are in contact with each other and heated in an oxidizing atmosphere. With such a member 112 and a structure 110 including the member 112, the amount of the inorganic material 105 that is discarded can be reduced. Furthermore, the strength of the member 112 including the newly manufactured composite material 111 is reduced to a degree that does not have a significant effect on the use of the composite material 111, compared to the physical properties (e.g., strength) of the composite material 111 manufactured using the inorganic material 105 that is a virgin material. Therefore, it is possible to obtain a member 112 and a structure 110 having physical properties such as desired strength.

[0058] Regarding physical properties, the physical properties of the inorganic material 105 of a virgin material and the physical properties of the inorganic material 105 obtained by the manufacturing method of the present disclosure (i.e., obtained by recycling the composite material 101) do not strictly match. Specifically, the physical properties of the inorganic material 105 change at least slightly due to heating for pyrolysis of the organic material 106. However, the degree of the change varies depending on the heating conditions during pyrolysis (e.g., heating temperature, heating time) and the shape of the composite material 101 during recycling. Therefore, it is impossible or impractical to quantitatively evaluate the physical properties of the inorganic material 105 obtained by recycling the composite material 101. Therefore, in the example of the present disclosure, the characteristics of the structure 110 are specified by the manufacturing method of the structure 110.

[0059] Moreover, when looking at the structure 110, whether the structure 110 was manufactured using the inorganic material 105, which is a virgin material, or the inorganic material 105 obtained by recycling the composite material 101 can be understood by evaluating the physical properties (e.g., mechanical strength) of the inorganic material 105. That is, if the evaluated mechanical strength is the same (or approximately the same) as the mechanical strength of the virgin material, the structure 110 can be said to have been manufactured using the inorganic material 105, which is a virgin material. On the other hand, if the evaluated mechanical strength does not have a significant effect on the use of the structure 110 but is lower than the mechanical strength of the virgin material, the structure 110 can be said to have been manufactured using the inorganic material 105 obtained by recycling the composite material 101.

[0060] 7 is a perspective view of a structure 120 according to another embodiment. The structure 120 includes a member 122. The member 122 is composed of a composition 121 including the above-mentioned composite material 101 (FIG. 1) and a decomposition-promoting component 102 (FIG. 1). The decomposition-promoting component 102 is present, for example, in the organic material 106 in the composite material 101. Therefore, for example, the inorganic material 105 and the decomposition-promoting component 102 are dispersed in the organic material 106.

[0061] 7, the inorganic material 105 can be separated by performing the heating step S3 on the structure 120 after use. This eliminates the need for the contact step S1 (FIG. 1), making it easy to recycle. EXAMPLES

[0062] The present disclosure will now be described more specifically with reference to examples.

[0063] <Example 1> A bisphenol A diglycidyl ether type thermosetting epoxy resin was used as the organic material 106 (Fig. 1), and glass fiber was used as the inorganic material 105 (Fig. 1) to produce a glass fiber reinforced plastic (GFRP) as the composite material 101 (Fig. 1). The content of the inorganic material 105 in the composite material 101 was set to 50 mass %. Therefore, the content of the organic material 106 in the composite material 101 was also 50 mass %. The composite material 101 was broken into chips measuring approximately 5 mm in length, 2 mm in width, and 0.2 mm in thickness.

[0064] Copper oxide (II) (CuO) was prepared as the decomposition-promoting component 102 (FIG. 1). The copper oxide (II) had an average particle size (D50) of 100 μm as measured by a laser diffraction particle size distribution measuring device. The chip-shaped composite material 101 and the decomposition-promoting component 102 were mixed (contact step S1) to obtain a mixture 107. The content of the decomposition-promoting component 102 in the mixture 107 was set to 50% by mass. Therefore, the content of the composite material 101 in the mixture 107 was also 50% by mass. Therefore, the content of the decomposition-promoting component 102 relative to the organic material 106 in the composite material 101 was 200% by mass.

[0065] The mixture 107 was used to analyze the decomposition behavior of the organic material 106. The analysis was performed using a thermal mass reduction device. The analysis conditions (decomposition conditions for the organic material 106) were to raise the temperature from room temperature to 700°C at 10°C / min. Here, the temperature at which the mass of the organic material 106 became 5% (i.e., almost no organic material 106 remained) was defined as the decomposition temperature, and a decomposition temperature of 440°C or less was evaluated as being capable of being decomposed at a low temperature. As a result of the analysis, the decomposition temperature was 362°C, and it was confirmed that the organic material 106 could be decomposed at 440°C or less.

[0066] <Example 2> The decomposition temperature was analyzed in the same manner as in Example 1, except that copper oxide (I) (CuO) was used instead of copper oxide (II). As a result, the decomposition temperature was 372°C.

[0067] <Example 3> Except for using elemental copper (Cu) instead of copper (II) oxide, the decomposition temperature was analyzed in the same manner as in Example 1. As a result, the decomposition temperature was 377°C.

[0068] <Example 4> The decomposition temperature was analyzed in the same manner as in Example 1, except that copper(II) acetylacetonate (Cu(C5H7O2)2) was used instead of copper(II) oxide. As a result, the decomposition temperature was 392°C.

[0069] <Example 5> The decomposition temperature was analyzed in the same manner as in Example 1, except that a mixture of copper oxide (II) and titanium oxide (TiO2) in a mass ratio of 55:45 was used instead of copper oxide (II). As a result, the decomposition temperature was 377°C.

[0070] <Example 6> Except for changing the mass ratio of copper (II) oxide to titanium oxide to 75:25, the decomposition temperature was analyzed in the same manner as in Example 5. As a result, the decomposition temperature was 376°C.

[0071] <Example 7> Except for using cobalt oxide (CoO) instead of titanium oxide, the decomposition temperature was analyzed in the same manner as in Example 5. As a result, the decomposition temperature was 363°C.

[0072] <Example 8> The decomposition temperature was analyzed in the same manner as in Example 7, except that the mass ratio of copper (II) oxide to cobalt oxide was changed to 75:25. As a result, the decomposition temperature was 356°C.

[0073] <Example 9> Except for using carbon fiber instead of glass fiber, the decomposition temperature was analyzed in the same manner as in Example 1. As a result, the decomposition temperature was 364°C.

[0074] <Example 10> The decomposition temperature was analyzed in the same manner as in Example 1, except that an unsaturated polyester resin, which is a thermosetting resin, was used instead of the bisphenol A diglycidyl ether type epoxy resin. As a result, the decomposition temperature was 366°C.

[0075] <Example 11> The decomposition temperature was analyzed in the same manner as in Example 1, except that the content of the decomposition-promoting component 102 in the mixture 107 was changed from 50% by mass to 20% by mass. Therefore, the content of the decomposition-promoting component 102 relative to the organic material 106 in the composite material 101 was 50% by mass. As a result, the decomposition temperature was 381°C.

[0076] <Example 12> The decomposition temperature was analyzed in the same manner as in Example 1, except that the content of the decomposition-promoting component 102 in the mixture 107 was changed from 50% by mass to 80% by mass. Therefore, the content of the decomposition-promoting component 102 relative to the organic material 106 in the composite material 101 was 800% by mass. As a result, the decomposition temperature was 377°C.

[0077] <Example 13> The decomposition temperature was analyzed in the same manner as in Example 1, except that the content of the decomposition-promoting component 102 in the mixture 107 was changed from 50 mass% to 4.8 mass%. Therefore, the content of the decomposition-promoting component 102 relative to the organic material 106 in the composite material 101 was 10 mass%. As a result, the decomposition temperature was 412°C.

[0078] In Example 13, the decomposition temperature exceeded 400°C, but was lower than the decomposition temperatures in Comparative Examples 1 to 7, which show the conventional technology, described below. Therefore, by using the decomposition-promoting component 10, the decomposition temperature can be lowered than before. However, in order to further lower the decomposition temperature, it was found that the content of the decomposition-promoting component 102 relative to the organic material 106 in the composite material 101 is preferably 50 mass% or more (Examples 1 to 12).

[0079] <Comparative Example 1> Except for using titanium oxide instead of copper (II) oxide, the decomposition temperature was analyzed in the same manner as in Example 1. As a result, the decomposition temperature was 505°C.

[0080] <Comparative Example 2> The decomposition temperature was analyzed in the same manner as in Example 1, except that dichromate (Cr2O3) was used instead of copper oxide (II). As a result, the decomposition temperature was 495°C.

[0081] <Comparative Example 3> Except for using zinc oxide (ZnO2) instead of copper oxide (II), the decomposition temperature was analyzed in the same manner as in Example 1. As a result, the decomposition temperature was 492°C.

[0082] <Comparative Example 4> Except for using nickel oxide (NiO) instead of copper oxide (II), the decomposition temperature was analyzed in the same manner as in Example 1. As a result, the decomposition temperature was 514°C.

[0083] <Comparative Example 5> The decomposition temperature was analyzed in the same manner as in Example 5, except that the mass ratio of copper (II) oxide to titanium oxide was changed to 25:75. As a result, the decomposition temperature was 445°C.

[0084] <Comparative Example 6> The decomposition temperature was analyzed in the same manner as in Example 1, except that copper-supported titanium oxide was used instead of copper (II) oxide. In the copper-supported titanium oxide, the transition metal element that is the main component in terms of mass ratio among the transition metal elements contained therein is titanium. As a result of the analysis, the decomposition temperature was 456°C.

[0085] <Comparative Example 7> The decomposition temperature was analyzed in the same manner as in Example 1, except that titanium oxide supporting iron was used instead of copper (II) oxide. In titanium oxide supporting iron, the transition metal element that is the main component in terms of mass ratio among the transition metal elements contained therein is titanium. As a result of the analysis, the decomposition temperature was 500°C.

[0086] <Summary> From the above results, it has been confirmed that, according to the present disclosure, the decomposition temperature can be reduced to, for example, 440° C. or lower, and the decomposition temperature can be particularly lowered compared to the case where a transition metal element other than copper is used as the main component.

[0087] <Differences in decomposition behavior due to differences in transition metal elements> The same thermosetting resin was used except for various changes to the metal oxide, and the content of the thermosetting resin and the metal oxide was set to a mass ratio of 1:1, and the decomposition behavior was analyzed in the same manner as in Example 1.

[0088] FIG. 8 is a graph showing the decomposition behavior of each decomposition-promoting component 102. The graph shown in FIG. 8 shows the difference in decomposition temperature due to the difference in the transition metal element of the main component contained in the decomposition-promoting component 102. The transition metal elements used are chromium (dotted line), nickel (dashed line), titanium (dashed line divided finer than the dashed line showing nickel), zinc (one-dot chain line), and copper (II) (two-dot chain line). Of these, copper (II) is an embodiment, and chromium, nickel, titanium, and zinc are all comparative examples. All of the transition metal elements are contained in the resin in the form of oxides. The vertical axis is mass, and the horizontal axis is temperature. The vertical axis is expressed as a relative ratio with the mass at the start of heating being 100%. FIG. 8 shows the change in mass reduction when the sample is heated in the thermal mass reduction device used in Example 1. For reference, the "resin" shown by the solid line is a reference example that does not contain the decomposition-promoting component 102. This point is the same as in FIG. 9 described later.

[0089] In all the examples, a mass reduction was observed as the temperature of the sample increased. This means that the organic material 106 was thermally decomposed as the temperature of the sample increased. In particular, in the oxides (comparative examples) other than copper oxide (II), the mass decreased gradually as the temperature increased. When copper oxide (II) (example) was used, the mass rapidly decreased when the sample was heated to about 350°C, and the mass decreased to nearly 0%. This result means that the thermal decomposition of the organic material 106 progressed rapidly at a specific temperature (about 350°C). The reason for this is not necessarily clear and is not limited to this reason, but according to the inventor's investigation, it is thought that the thermal decomposition progressed in a chain reaction. Therefore, it can be seen that the use of copper oxide (II) can promote the thermal decomposition of the organic material 106, and as a result, it can be thermally decomposed at a lower temperature than other metals.

[0090] FIG. 9 is a graph showing the decomposition behavior of each decomposition-promoting component 102 according to another embodiment. The conditions were the same as those shown in FIG. 8 except that the decomposition-promoting component 102 was different, and the mass loss change was analyzed. The decomposition-promoting components 102 are titanium oxide (thin dotted line), titanium oxide supporting copper (thick dashed line), titanium oxide supporting iron (dashed line), copper alone (thin dashed line), copper oxide (I) (thick dotted line), and copper oxide (II) (dash-dotted line). As described above, in both titanium oxide supporting copper and titanium oxide supporting iron, the transition metal element that is the main component in terms of mass ratio among the transition metal elements contained therein is titanium. Therefore, among these, copper alone, copper oxide (I) and copper oxide (II) are embodiments, and titanium oxide, titanium oxide supporting copper, and titanium oxide supporting iron are all comparative examples.

[0091] When the decomposition-promoting component 102 contains copper as a main component, that is, when it is copper alone (thin dashed line), copper oxide (I) (thick dotted line), or copper oxide (II) (double-dotted line), the mass is almost 0% at 400°C or less. In particular, when copper oxide, that is, copper oxide (I) or copper oxide (II), or copper alone is used, the mass is rapidly reduced at about 350°C as described in FIG. 8 above. Among the composite materials 101, there may be composite materials 101 that are used at a relatively high temperature. For this reason, by using a decomposition-promoting component 102 that undergoes a gradual change in mass until it reaches a relatively high temperature and rapidly reduces in mass at a specific temperature, the degree of mass reduction can be suppressed to a small extent even when the composite material 101 is used at a relatively high temperature (but below the specific temperature). [Explanation of symbols]

[0092] 1 Reactor 101 Composite materials 102 Degradation accelerating components 103 Gas 104 Exhaust Gas 105 Inorganic materials 106 Organic materials 107 Mixture 110 Structures 111 Composite materials 112 Components 120 Structures 122 Materials 2 Heating mechanism 200 Manufacturing equipment 3 Air outlet 4. Exhaust port 5 Stirring mechanism 6. Collection Mechanism S1 Contact process S2 Atmosphere control process S3 heating process S31 Preheating process S32 Main heating process

Claims

1. A composite material including an organic material composed of an organic substance and an inorganic material composed of an inorganic substance; a decomposition-promoting component that promotes the thermal decomposition of the organic material and contains copper as a main component by mass ratio among the transition metal elements contained therein; The method includes a heating step of heating the mixture in an oxidizing atmosphere while the mixture is in contact with the A method for producing an inorganic material comprising the steps of:

2. The inorganic material includes at least one of carbon fiber and glass fiber. The method for producing an inorganic material according to claim 1 .

3. The decomposition-promoting component contains copper as an element. The method for producing an inorganic material according to claim 1 .

4. The decomposition-promoting component contains at least one of copper oxide (I) and copper oxide (II). The method for producing an inorganic material according to claim 1 .

5. The decomposition-promoting component includes an organic copper compound. The method for producing an inorganic material according to claim 1 .

6. The decomposition-promoting component has a particle shape. The method for producing an inorganic material according to claim 1 .

7. The organic material includes a thermosetting resin. The method for producing an inorganic material according to claim 1 .

8. The heating step is carried out by heating at a temperature at which the organic material is thermally decomposed. The method for producing an inorganic material according to claim 1 .

9. The heating step is carried out at a temperature of 400° C. or less. The method for producing an inorganic material according to claim 8 .

10. The heating step is carried out while subjecting at least one of the composite material and the decomposition-promoting component to at least one of vibration and stirring in a state in which the composite material and the decomposition-promoting component are in contact with each other. The method for producing an inorganic material according to claim 1 .

11. A contacting step of contacting the composite material with the decomposition-promoting component is included, The heating step is carried out using the reaction vessel used in the contact step. The method for producing an inorganic material according to claim 1 .

12. The decomposition-promoting component does not include an oxide semiconductor (except for copper oxide). The method for producing an inorganic material according to claim 1 .

13. The decomposition-promoting component does not contain any transition metal elements (except copper). The method for producing an inorganic material according to claim 1 .

14. The content of the decomposition-promoting component relative to the organic material is 50% by mass or more. The method for producing an inorganic material according to claim 1 .

15. A composite material including an organic material composed of an organic substance and an inorganic material composed of an inorganic substance; a reaction vessel containing a decomposition-promoting component that promotes the thermal decomposition of the organic material and contains copper as a main component by mass ratio among the transition metal elements contained therein; a heating mechanism for heating the composite material and the decomposition-promoting component inside the reaction vessel; an air supply port for supplying an oxygen-containing gas into the reaction vessel; and an exhaust port for exhausting gas generated inside the reaction tank from the reaction tank. An apparatus for producing an inorganic material.

16. A stirring mechanism is provided for stirring the composite material and the decomposition-promoting component inside the reaction tank.

16. The apparatus for producing an inorganic material according to claim 15.

17. A recovery mechanism is provided for recovering the inorganic material obtained by thermal decomposition of the organic material in the composite material from inside the reaction tank.

16. The apparatus for producing an inorganic material according to claim 15.

18. The gas exhausted from the exhaust port includes gas generated by thermal decomposition of the organic material.

16. The apparatus for producing an inorganic material according to claim 15.

19. A composite material including an organic material composed of an organic substance and an inorganic material composed of an inorganic substance; a decomposition-promoting component that promotes the thermal decomposition of the organic material and contains copper as a main component by mass ratio among the transition metal elements contained therein; The present invention provides a member containing the inorganic material, which is manufactured by at least a heating step of heating the inorganic material in an oxidizing atmosphere while contacting the inorganic material with the inorganic material. A structure characterized by:

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