Method for manufacturing inorganic material, apparatus for manufacturing inorganic material, and method for disassembling composite material

Abstract

To provide a method for producing an inorganic material by which the thermal decomposition temperature of an organic material can be made lower than that of a conventional method.SOLUTION: A method for producing an inorganic material includes a heat-treatment step S3 of heat-treating an integrated object 107 in which a composite material 101 containing an inorganic material 105 composed of an inorganic substance and an organic material 106 composed of an organic substance is in contact with a decomposition-accelerating ingredient 102 for accelerating thermal decomposition of the organic material 106, wherein the decomposition-accelerating ingredient 102 contains manganese dioxide as a main ingredient. The S3 is performed at a temperature of 250 °C or more and 400 °C or less.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 method for decomposing a composite material. [Background technology]

[0002] In response to environmental regulations and energy conservation, efforts are being made to reduce the weight of structures such as home appliances, railway vehicles, aircraft, and automobiles. Among these, composite materials such as fiber-reinforced resins containing inorganic materials such as fibers and fillers are being used as structural components. This reduces the weight and improves the rigidity of structural components. However, composite materials contain multiple materials, and there is a demand for separating the inorganic materials from the composite materials in order to recycle the inorganic materials. Patent Document 1 describes a technique for separating the inorganic materials from the composite materials.

[0003] The abstract of Patent Document 1 states that "when producing fuel from a treatment object containing a polymeric organic substance, the method includes a step of contacting the treatment object with a catalyst containing an oxide semiconductor and a transition metal element, and 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] Japanese Patent Publication No. 2022-55446 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, organic matter in a composite material is burned using a catalyst containing manganese (paragraphs 0023 and 0026). This allows the inorganic matter in the composite material to be separated. The combustion is carried out in an atmosphere containing hydrogen and oxygen (paragraph 0028). Details will be described later with reference to the examples, but the inventors' investigations have revealed that the use of manganese dioxide, rather than simple manganese, can significantly reduce the thermal decomposition temperature. The problem to be solved by the present disclosure is to provide a method for producing an inorganic material, an apparatus for producing an inorganic material, and a method for decomposing a composite material, which are capable of lowering the thermal decomposition temperature of an organic material compared to conventional methods. [Means for solving the problem]

[0006] The method for producing an inorganic material according to the present disclosure includes a heating step of heating an integrated product in which a composite material containing an inorganic material composed of an inorganic substance and an organic material composed of an organic substance is in contact with a decomposition-promoting component that promotes the thermal decomposition of the organic material, the decomposition-promoting component containing manganese dioxide as a main component. Other solutions will be described later in the description of the preferred embodiments of the present invention. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a method for producing an inorganic material, an apparatus for producing an inorganic material, and a method for decomposing a composite material, which are capable of lowering the thermal decomposition temperature of an organic material compared to conventional methods. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flowchart illustrating a method for producing an inorganic material according to the present disclosure. [Figure 2] 10 is a flowchart showing a method for manufacturing an inorganic material according to another embodiment. [Figure 3] 10 is a flowchart showing a method for manufacturing an inorganic material according to another embodiment. [Figure 4] FIG. 1 is a perspective view showing the inside of an inorganic material manufacturing apparatus according to the present disclosure. [Figure 5] FIG. 10 is a perspective view showing the inside of an inorganic material manufacturing apparatus according to another embodiment. [Figure 6]1 is a graph showing the change in mass of organic materials for each decomposition-accelerating component. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as "embodiments") 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 one embodiment described below, and different embodiments can be combined with each other or modified as desired without significantly impairing the effects of the present disclosure. Furthermore, the same components will be given the same reference numerals, and redundant descriptions will be omitted. Furthermore, components having the same functions will be given the same names. The contents shown are merely schematic, and for convenience of illustration, changes may be made from the actual configuration within the scope of not significantly impairing the effects of the present disclosure, and some components may be omitted or modified between drawings. Furthermore, the same embodiment does not necessarily have to include all of the configurations.

[0010] FIG. 1 is a flowchart showing a method for producing an inorganic material according to the present disclosure (hereinafter simply referred to as the "production method according to the present disclosure"). The production method according to the present disclosure can be performed using, for example, a production apparatus 200 shown in FIG. 4, which will be described later. The production method according to the present disclosure is a method for producing an inorganic material 105 from a composite material 101 containing an inorganic material 105 and an organic material 106 (e.g., consisting of the inorganic material 105 and the organic material 106). The inorganic material 105 can be produced by thermally decomposing (e.g., oxidatively decomposing (combustion, etc.)) the organic material 106 in the composite material 101. Therefore, the production method according to the present disclosure is also a method for decomposing a composite material 101 according to the present disclosure (hereinafter simply referred to as the "decomposition method according to the present disclosure"). The following description will focus on the production method according to the present disclosure, and a description of the decomposition method according to the present disclosure will be omitted as appropriate. The matters described below regarding the production method according to the present disclosure can be similarly applied to the decomposition method according to the present disclosure.

[0011] First, for convenience of explanation, the inorganic material 105, the organic material 106, and the composite material 101 will be explained, and then the manufacturing method of the present disclosure (the decomposition method of the present disclosure) will be explained.

[0012] The composite material 101 can be, for example, so-called "waste plastics" obtained from waste products such as home appliances (washing machines, dryers, refrigerators, vacuum cleaners, hot water heaters, etc.), aircraft, railroad cars, automobiles, and industrial products. Therefore, the manufacturing method (disassembly 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 obtained inorganic material 105 can be reused as a part of a new composite material 101, for example, as a recycled material.

[0013] The inorganic material 105 in the composite material 101 from which the inorganic material 105 is produced (separated and recovered) may be a virgin material or a recycled material. The recycled material may be, for example, an inorganic material 105 produced by the production method of the present disclosure. Hereinafter, when simply referring to the "inorganic material 105," the inorganic material 105 may be either a virgin material or a recycled material unless otherwise specified.

[0014] In the decomposition method of the present disclosure, the organic material 106 in the composite material 101 is thermally decomposed at a lower temperature than conventionally used (for example, 500°C or lower, preferably 450°C or lower, and more preferably 400°C or lower), as will be described in detail later. 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 considered oxidative decomposition. By performing the thermal decomposition at a lower temperature than conventionally used, thermal degradation of the inorganic material 105 contained together with the organic material 106 can be suppressed, and changes in the physical properties of the inorganic material 105, such as a decrease in strength, can be suppressed. This makes it possible to produce a new composite material 101 whose physical properties are comparable to those of a composite material 101 using virgin inorganic material 105.

[0015] 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 inorganic fibers can be used alone or in combination of two or more. Inorganic 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 state is not limited to these fiber shapes or states.

[0016] Examples of inorganic fillers include powders of 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., as well as beads obtained by spheroidizing these. There are no limitations on the shape of the inorganic filler, and any shape, such as spherical or flaky, may be used.

[0017] Examples of metals contained in the inorganic material 105 include steel, aluminum, aluminum alloys, magnesium alloys, titanium alloys, etc. There is no limitation on the shape of the metal, and any shape such as plate, sphere, or flake may be used.

[0018] Of these, the inorganic material 105 preferably includes 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 this 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 compared to conventional methods. Therefore, the organic material 106 can be easily thermally decomposed, and the inorganic material 105 can be removed (manufactured) from the composite material 101.

[0019] 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 thermosetting resins include epoxy resin, phenolic resin, urea resin, melamine resin, unsaturated polyester resin, silicone resin, polyimide resin, bismaleimide resin, and thermosetting urethane resin. Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, acrylonitrile 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 desired ratio.

[0020] In particular, it is preferable that the organic material 106 contains a thermosetting resin. Because a thermosetting resin hardens when heated, it is difficult to melt the organic material 106, and it is difficult to separate the inorganic material 105 contained therein 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 conventional methods. This allows the organic material 106 to be easily thermally decomposed, and the inorganic material 105 to be extracted from the composite material 101.

[0021] When the inorganic material 105 is a resin and the organic material 106 is a fiber, the composite material 101 is, for example, a fiber-reinforced resin.

[0022] There are no particular limitations on the contents of inorganic material 105 and organic material 106 in composite material 101. For example, the content of inorganic material 105 in composite material 101 may be 30% by mass or more and 70% by mass or less, and the remainder other than inorganic material 105 may be organic material 106.

[0023] The composite material 101 may contain additives such as flame retardants, antioxidants, light stabilizers, dispersants, lubricants, plasticizers, antistatic agents, pigments, and dyes, as needed.

[0024] The decomposition method of the present disclosure includes a contacting step S1, an atmosphere controlling step S2, and a heating step S3.

[0025] The contacting step S1 is a step of bringing the composite material 101 and the decomposition-promoting component 102 into contact with each other. The contact results in an integrated product 107 in which the composite material 101 and the decomposition-promoting component 102 have come into contact with each other. In the present disclosure, mixing is exemplified as an example of contact. Therefore, the contacting of the composite material 101 with the decomposition-promoting component 102, i.e., mixing, produces a mixture containing the composite material 101 and the decomposition-promoting component 102 (an example of the integrated product 107). Note that the "mixing" does not necessarily mean that the composite material 101 and the decomposition-promoting component 102 are mixed completely and uniformly; for example, the composite material 101 and the decomposition-promoting component 102 may coexist in the same reaction vessel 1 (FIG. 4).

[0026] The manner of contact is not particularly limited. For example, composite material 101 pulverized into rods having a length of approximately 1 mm to 10 mm can be mixed with decomposition-promoting component 102 in powder form (for example, an average particle size determined by a laser diffraction scattering method of, for example, 10 μm to 500 μm). In particular, by using decomposition-promoting component 102 in powder form and bringing powdered decomposition-promoting component 102 into contact with composite material 101, the contact area between decomposition-promoting component 102 and composite material 101 can be increased. This can promote the thermal decomposition of organic material 106 that occurs at the contact area between decomposition-promoting component 102 and organic material 106.

[0027] The contact (e.g., mixing) can be carried out, for example, inside the reaction vessel 1 (an example of a vessel). Specifically, the contact can be carried out by placing the composite material 101 and the decomposition-promoting component 102 in the reaction vessel 1 and appropriately stirring, vibrating, 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. Alternatively, since it is sufficient that the composite material 101 and the decomposition-promoting component 102 are in contact with each other, the composite material 101 may be placed on a plate-shaped decomposition-promoting component 102 and brought into contact with it.

[0028] The decomposition-promoting component 102 is a component that promotes the thermal decomposition of the organic material 106. The decomposition-promoting component 102 contains manganese dioxide (MnO2) as a main component. The term "main component" as used herein refers to the component (simple substance or compound) that is contained in the decomposition-promoting component 102 in the largest amount by mass. For example, the main component is the component in question when only one component is contained; the main component is the component in a relatively large amount when two components are contained; and the main component is the component in a largest amount when three or more components are contained. This allows the amount of organic material 106 to be thermally decomposed to be increased, as described above, and improves the efficiency of the heat treatment of the composite material 101.

[0029] The amount of manganese dioxide used is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the entire amount of decomposition-promoting component 102. Although details will be described later, by using decomposition-promoting component 102 containing manganese dioxide as the main component, organic material 106 can be thermally decomposed at a lower temperature than conventional methods.

[0030] Unlike other compounds (e.g., oxides) other than manganese dioxide, the mechanism by which manganese dioxide can oxidatively decompose organic material 106 at low temperatures is not entirely clear, but the following mechanism is conceivable, for example: However, the following mechanism is merely speculation, is not limited to this, and other reasons may also be possible.

[0031] For example, when manganese dioxide is heated in the contact step S1, thermal excitation occurs inside the manganese dioxide, generating holes and electrons. The holes, due to their oxidative power, steal electrons from organic matter (organic material 106) present around the manganese dioxide, thereby oxidizing and decomposing the organic matter. In addition, the electrons generated by thermal excitation move to oxygen contained in the atmosphere, generating active oxygen. The active oxygen promotes the oxidative decomposition of organic matter, which also leads to the oxidative decomposition of the organic matter.

[0032] Here, when manganese elemental rather than manganese dioxide is used and heated in an oxidizing atmosphere, the manganese elemental is oxidized. However, manganese in manganese oxides can have multiple valences, such as divalent, trivalent, tetravalent, pentavalent, hexavalent, and heptavalent. Simply oxidizing manganese in an oxidizing atmosphere does not necessarily result in the manganese elemental being tetravalent, which is the valence in manganese dioxide. Therefore, using manganese elemental is not expected to lower the thermal decomposition temperature.

[0033] Therefore, the reduction in the thermal decomposition temperature can only be achieved by using manganese dioxide, rather than manganese alone, as the decomposition-promoting component 102. That is, it has been revealed that by using manganese dioxide, among manganese alone and various oxides, during thermal decomposition, it is possible to carry out thermal decomposition at a low temperature (for example, 400°C or lower).

[0034] The use of manganese dioxide also provides the following effects. Specifically, manganese dioxide acts as an oxidizing agent, and the oxygen contained in the manganese dioxide may oxidize organic matter. That is, manganese, which constitutes manganese dioxide, is more likely to release oxygen than other transition metal elements. Therefore, manganese dioxide releases its own oxygen, and the released oxygen acts on organic matter, promoting the oxidative decomposition of the organic matter. Meanwhile, manganese reduced by the release of oxygen is quickly oxidized by atmospheric oxygen and surrounding manganese dioxide (oxidizing agent) to return to manganese dioxide with a valence of 4. In particular, since the manganese that is oxidized is manganese derived from manganese dioxide, manganese dioxide is preferentially produced by oxidation. In this way, the use of manganese dioxide acts externally like a catalyst, allowing the decomposition-promoting component 102 to be used repeatedly.

[0035] The decomposition-promoting component 102 may additionally contain a component other than manganese dioxide (a component that promotes the thermal decomposition of the organic material 106). Such a component may be, for example, an oxide semiconductor. Specifically, the decomposition-promoting component 102 may additionally contain at least one of a thermally stable oxide semiconductor compound and a compound that generates a thermally stable oxide semiconductor upon heating with the organic material 106. Examples of such compounds include at least one of CaO, MnO, ZrO2, WO2, CuO, TiO2, VO5, Cr2O3, NiO, Fe2O3, Fe3O4, ZnO, CoO, and Co3O4. Furthermore, the decomposition-promoting component 102 may contain an oxide semiconductor that can be oxidized back to manganese dioxide when manganese dioxide acts as an oxidizing agent and manganese is reduced. Examples of such oxide semiconductors include TiO2 (titanium oxide) and CuO (copper (II) oxide).

[0036] The manganese dioxide content is, for example, 100% by mass or more, preferably 150% by mass or more, more preferably 200% by mass or more, even more preferably 300% by mass or more, and particularly preferably 500% by mass or more, relative to the mass of the organic material 106. By using an amount of manganese dioxide within this range, the organic material 106 can be thermally decomposed. However, the manganese dioxide content can be adjusted appropriately depending on the shapes of the organic material 106 and the decomposition-promoting component 102, etc. The decomposition temperature tends to decrease as the amount of manganese dioxide used increases. The upper limit of the manganese dioxide content is, for example, 1000% by mass, preferably 700% by mass, relative to the mass of the organic material 106, but is not limited to these.

[0037] 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. In the example of the present disclosure, for example, the atmosphere of the space (internal space of the reaction vessel 1) in which the integrated object 107 obtained in the contact step S1 is present is controlled. In the atmosphere control step S2, for example, the atmosphere of the space in which the integrated object 107 is placed is controlled to an oxygen-containing gas 103 (FIG. 4), thereby controlling the space to an oxidizing atmosphere. That is, the integrated object 107 is present in the gas 103. The oxidizing atmosphere gas 103 is, for example, air, oxygen gas, etc., but may also contain, for example, 0.01% by volume or less of hydrogen.

[0038] In addition, if at least one of the composite material 101 and the decomposition-promoting component 102 contains a component that can create a desired atmosphere during the heating step S3 (for example, a component that generates oxygen), the atmosphere control step S2 does not need to be included.

[0039] The heating step S3 is a step of heating the integral body 107 in which the composite material 101 and the decomposition-promoting component 102 are in contact with each other. In the example of the present disclosure, the heating step S3 is a step of heating the integral body 107 present in the gas 103 inside the reaction vessel 1.

[0040] Heating step S3 is performed by heating at a temperature that thermally decomposes organic material 106. Heating at this temperature allows organic material 106 to be thermally decomposed. Specifically, heating step S3 is performed at a temperature of, for example, 200°C or higher and 420°C or lower, preferably 230°C or higher and 400°C or lower, more preferably 250°C or higher and 370°C or lower, and particularly preferably 300°C or higher and 350°C or lower. In particular, heating step S3 is preferably performed at a temperature of 250°C or higher and 400°C or lower. Heating within this temperature range allows organic material 106 to be thermally decomposed, and also makes it possible to suppress thermal degradation of inorganic material 105, which has a significant impact when recycled inorganic material 105 is reused.

[0041] As described above, the heating step S3 is preferably performed in an oxidizing atmosphere, which can promote oxidative decomposition of the organic material 106. Furthermore, as described above, the manganese dioxide can be reused repeatedly.

[0042] The oxidizing atmosphere referred to here is preferably a gas containing oxygen and, for example, a hydrogen content of 0.01% by volume or less (it may contain no hydrogen at all). By using such a gas, the organic material 106 can be oxidatively decomposed, and the generation of minor components such as hydrocarbons due to the coexistence of hydrogen can be suppressed. The hydrogen content is preferably an amount that does not create a reducing atmosphere, for example, 0.01% by volume or less, but may also be, for example, 0.1% by volume or less, preferably 0.05% by volume or less.

[0043] The heating step S3 is preferably performed in a gas phase such as gas 103. That is, it is preferable to heat the integrated body 107 in a gas phase of an oxidizing atmosphere. This makes it easier to control the heating temperature and to remove the inorganic material 105.

[0044] The heating step S3 is preferably performed while at least one of vibrating and stirring the integrated object 107. This increases the contact opportunity between the composite material 101 and the decomposition-promoting component 102, and suppresses a decrease in reaction efficiency due to uneven reaction.

[0045] The heating step S3 is preferably carried out inside the reaction tank 1 (container) used in the contacting step S1. That is, after the contacting step S1 in which the composite material 101 and the decomposition-promoting component 102 are brought into contact inside the reaction tank 1, it is preferable to carry out the heating step S3 directly inside the reaction tank 1 without transferring the integrated object 107 to another container. This can reduce the effort required to put the composite material 101 and the like into and take it out of the reaction tank 1, and the inorganic material 105 can be produced continuously.

[0046] The heating time in the heating step S3 is not particularly limited, but may be, for example, 5 minutes to 2 hours.

[0047] The solid organic material 106 is converted into exhaust gas 104 (FIG. 4) by thermal decomposition of the organic material 106 in the heating step S3. The exhaust gas 104 contains, for example, carbon dioxide and is appropriately discharged to the outside. Meanwhile, the inorganic material 105 contained in the composite material 101 remains in the reaction vessel 1. Therefore, the inorganic material 105 can be extracted from the reaction vessel 1.

[0048] FIG. 2 is a flowchart showing another embodiment of a method for producing an inorganic material 105. In the embodiment shown in FIG. 2, unlike the embodiment shown in FIG. 1, a contact step S1 is performed after the 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 (contained) is, for example, an oxidizing atmosphere, and is composed of, for example, a gas 103 (FIG. 4) containing oxygen (atmosphere control step S2). Therefore, the decomposition-promoting component 102 is present in the gas 103. Then, by further containing a composite material 101 in this state in the reaction vessel 1, the atmosphere around the integrated object 107 becomes, for example, an oxidizing atmosphere (contact step S1).

[0049] The embodiment shown in FIG. 2 also makes it possible to oxidatively decompose the organic material 106 at a lower temperature than conventional methods.

[0050] FIG. 3 is a flowchart showing another embodiment of a method for producing an inorganic material 105. In the embodiment shown in FIG. 3, the heating step S3 in the embodiment shown in FIG. 2 above includes a preheating step S31 and a main heating step S32. After the atmosphere control step S2, the preheating step S31, which is part of the heating step S3, is performed. The preheating step S31 is a step of raising the temperature of the decomposition-promoting component 102 to the heating temperature in the main heating step S32 described below. After the temperature of the decomposition-promoting component 102 is raised to the desired temperature, the composite material 101 is introduced into the reaction vessel 1, and an integrated object 107 is produced (contact step S1). Then, the main heating step S32 is performed on the integrated object 107. The main heating step S32 can be performed in the same manner as the heating step S3 described above with reference to FIG. 1 etc.

[0051] 3 also makes it possible to oxidatively decompose organic material 106 at a lower temperature than conventional methods. Furthermore, because composite material 101 is brought into contact with preheated decomposition-promoting component 102, it is possible to shorten the time required from bringing composite material 101 into contact with decomposition-promoting component 102 until the temperature is raised to a temperature at which the composite material 101 can be thermally decomposed. This shortens the processing time for composite material 101.

[0052] Fig. 4 is a perspective view showing the inside of a manufacturing apparatus 200 for an inorganic material 105 according to the present disclosure. Fig. 4 illustrates an integrated object 107 in which a composite material 101 is uniformly dispersed in a powdered (particulate) decomposition-promoting component 102. In other words, the composite material 101 broken (crushed) into elongated rod shapes (chip shapes) is embedded in the powdered decomposition-promoting component 102. However, the integrated object 107 is not limited to the shape shown in the figure, and it is sufficient that the composite material 101 and the decomposition-promoting component 102 come into contact with each other and are integrated together.

[0053] The manufacturing apparatus 200 includes a reaction vessel 1, a heating mechanism 2, a supply port 3, a discharge port 4, and a stirring mechanism 5. The reaction vessel 1 (storage vessel) is a vessel that stores a composite material 101 and a decomposition-promoting component 102. In the example of the present disclosure, a thermal decomposition reaction (oxidative decomposition reaction) of the organic material 106 in the composite material 101 proceeds inside the reaction vessel 1. In the example of the present disclosure, the reaction vessel 1 is, for example, a hollow tank. The heating mechanism 2 is a mechanism that heats the inside of the reaction vessel 1. In the example of the present disclosure, the heating mechanism 2 heats the composite material 101 and the decomposition-promoting component 102 inside the reaction vessel 1. The heating mechanism 2 is provided at the bottom of the reaction vessel 1 and heats the composite material 101 and the decomposition-promoting component 102 from the bottom of the reaction vessel 1. The heating mechanism 2 is, for example, an electric heating wire, a boiler, or the like.

[0054] The supply port 3 is an opening (air inlet) for supplying a fluid into the reaction vessel 1. The fluid is, for example, gas 103. As described above, the gas 103 is a gas containing oxygen. Preferably, the gas 103 contains oxygen and has a hydrogen content of 0.01% by volume or less (it may contain no hydrogen at all). The outlet 4 is an opening (exhaust port) for discharging the fluid inside the reaction vessel 1 from the reaction vessel 1. The fluid is, for example, exhaust gas 104. The exhaust gas 104 contains gas (e.g., carbon dioxide, water vapor, etc.) generated by the thermal decomposition of the organic material 106. When the organic material 106 is discharged from the reaction vessel 1 as a gas, the inorganic material 105 remains inside the reaction vessel 1, making it easier to remove the inorganic material 105. The supply port 3 and the outlet 4 are provided at the top of the reaction vessel 1. Note that the exhaust gas 104 may also contain unreacted gas 103.

[0055] 5 is a perspective view showing the inside of a manufacturing apparatus 200 for manufacturing an inorganic material 105 according to another embodiment. The manufacturing apparatus 200 shown in FIG. 5 further includes a separation mechanism 6 that separates the inorganic material 105 from the inside of the reaction tank 1. The separation mechanism 6 is, for example, provided near the bottom of the reaction tank 1, and is an opening (separation port) that can separate the inorganic material 105 produced in the reaction tank 1 from the integral mass 107. By including the separation mechanism 6, for example, the inorganic material 105 can be separated from the integral mass 107 that remains while the oxidative decomposition reaction is progressing in the reaction tank 1.

[0056] The present disclosure is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described to clearly explain the present disclosure, and the present disclosure is not necessarily limited to those having all of the described configurations. Next, the manufacturing method, manufacturing apparatus 200, and disassembly method of the present disclosure will be described in more detail with reference to examples. [Example]

[0057] Example 1 A bisphenol A diglycidyl ether type thermosetting epoxy resin (thermosetting resin) was used as the organic material 106, and glass fiber was used as the inorganic material 105, to produce a glass fiber reinforced plastic (GFRP) as the composite material 101. The content of inorganic material 105 in the composite material 101 was set to 50 mass %. Therefore, the content of 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.

[0058] Powdered manganese dioxide (MnO2) was prepared as the decomposition-promoting component 102. The particle size of the manganese dioxide was 50 μm as an average particle size based on a laser diffraction scattering method. The chip-shaped composite material 101 and the powdered decomposition-promoting component 102 were mixed to obtain a monolithic body 107. The content of manganese dioxide (decomposition-promoting component 102) in the monolithic body 107 was set to 75 mass %. Therefore, the content of the composite material 101 in the monolithic body 107 was also 25 mass %. Therefore, the content of manganese dioxide relative to the organic material 106 in the composite material 101 was 600 mass %.

[0059] The decomposition behavior of the organic material 106 was analyzed using the monolith 107. The analysis was performed using a thermal mass reduction device. The analysis was performed by heating the monolith 107 from room temperature (25°C) to 700°C at a rate of 10°C / min. The analysis was performed by exposing the monolith 107 to an oxidizing atmosphere containing oxygen and with a hydrogen content of 0.01% by volume or less. The temperature at which the mass of the organic material 106 became 1% (i.e., almost no organic material 106 remained) was defined as the decomposition temperature.

[0060] Analysis revealed that the decomposition temperature was 300°C.

[0061] <Example 2> The decomposition temperature was analyzed in the same manner as in Example 1, except that the content of manganese dioxide relative to the organic material 106 in the composite material 101 was set to 100 mass %. As a result, the decomposition temperature was 378°C.

[0062] Example 3 The decomposition temperature was analyzed in the same manner as in Example 1, except that the content of manganese dioxide relative to the organic material 106 in the composite material 101 was set to 1000 mass %. As a result, the decomposition temperature was 302°C.

[0063] Example 4 The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese dioxide and copper (II) oxide (CuO) were used in combination as decomposition-accelerating component 102. In decomposition-accelerating component 102, the content of manganese dioxide (main component) was 100 mass %, and the content of copper (II) oxide was 50 mass %. The decomposition temperature was 359°C.

[0064] <Example 5> The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese dioxide and titanium oxide were used in combination as decomposition-promoting component 102. The content of manganese dioxide (main component) in decomposition-promoting component 102 was 100 mass %, and the content of titanium oxide was 50 mass %. The decomposition temperature was 377°C.

[0065] Example 6 The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese dioxide and titanium oxide were used in combination as decomposition-promoting component 102. The content of manganese dioxide (main component) in decomposition-promoting component 102 was 100 mass %, and the content of titanium oxide was 90 mass %. The decomposition temperature was 382°C.

[0066] Example 7 The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese dioxide and copper oxide (I) (CuO) were used in combination as decomposition-accelerating component 102. In decomposition-accelerating component 102, the content of manganese dioxide (main component) was 100 mass %, and the content of copper oxide (I) was 50 mass %. The decomposition temperature was 381°C.

[0067] Example 8 The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese dioxide and copper oxide (I) (CuO) were used in combination as decomposition-accelerating component 102. In decomposition-accelerating component 102, the content of manganese dioxide (main component) was 100 mass %, and the content of copper oxide (I) was 90 mass %. The decomposition temperature was 385°C.

[0068] Example 9 The decomposition temperature was analyzed in the same manner as in Example 1, except that carbon fiber was used instead of glass fiber. As a result, the decomposition temperature was 302°C.

[0069] 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 312°C.

[0070] <Comparative Example 1> The decomposition temperature was analyzed in the same manner as in Example 1, except that copper (II) oxide (CuO) was used instead of manganese dioxide as the decomposition-accelerating component. As a result, the decomposition temperature was 401°C.

[0071] <Comparative Example 2> The decomposition temperature was analyzed in the same manner as in Example 1, except that titanium oxide was used instead of manganese dioxide as the decomposition-promoting component. As a result, the decomposition temperature was 538°C.

[0072] <Comparative Example 3> The decomposition temperature was analyzed in the same manner as in Example 1, except that chromium oxide was used instead of manganese dioxide as the decomposition-accelerating component. As a result, the decomposition temperature was 473°C.

[0073] <Comparative Example 4> The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese monoxide (MnO; manganese has a valence of 2) was used instead of manganese dioxide as the decomposition-promoting component. As a result, the decomposition temperature was 508°C.

[0074] <Comparative Example 5> The decomposition temperature was analyzed in the same manner as in Example 1, except that trimanganese tetroxide (Mn3O4; manganese valences are divalent and trivalent) was used instead of manganese dioxide as the decomposition-promoting component. As a result, the decomposition temperature was 543°C.

[0075] <Comparative Example 6> The decomposition temperature was analyzed in the same manner as in Example 1, except that manganese (Mn, manganese element; manganese valence is 0) was used instead of manganese dioxide as the decomposition-promoting component. As a result, the decomposition temperature was 554°C. <Summary> The above results are summarized in Table 1 below.

[0076] [Table 1]

[0077] As described above, Patent Document 1 discloses that manganese can be used. However, by using manganese dioxide (Example 1), the decomposition temperature could be significantly reduced by approximately 200°C to 250°C compared to manganese oxides other than manganese dioxide (Comparative Examples 4 and 5) and manganese alone (Comparative Example 6). Therefore, it was found that by using manganese dioxide, organic material 106 can be thermally decomposed (oxidatively decomposed) at a lower temperature than conventional methods. It was also found that by using manganese dioxide, organic material 106 can be thermally decomposed (oxidatively decomposed) at a lower temperature than oxides other than manganese dioxide (Comparative Examples 1 to 3).

[0078] Furthermore, it was found that even when manganese dioxide was used in combination with other metal oxides (copper (II) oxide, titanium oxide, copper (I) oxide, etc.) (Examples 4 to 8), the organic material 106 could be thermally decomposed (oxidatively decomposed) at a lower temperature than in the conventional case (Comparative Examples 4 to 6). Furthermore, the results of Examples 1 to 3 showed that the decomposition temperature decreased as the amount of manganese dioxide used increased.

[0079] <Differences in decomposition behavior due to differences in decomposition-promoting components> FIG. 6 is a graph showing the change in mass of the organic material for each decomposition-promoting component. The horizontal axis is temperature, and the vertical axis is the mass of the organic material 106. The thick solid line graph (reference example) shows the change in mass of the organic material 106 containing only the organic material 106 (resin). The dotted line graph (comparison example) shows the change in mass of the organic material 106 when titanium oxide is used. The thin dashed dotted line graph shows the change in mass of the organic material 106 when copper oxide (CuO(II) (comparison example)) is used. The thick dashed line graph (Comparative Example) represents the change in mass of organic material 106 when manganese monoxide (MnO) was used. The coarse dashed line graph (Comparative Example) represents the change in mass of organic material 106 when manganese monoxide (MnO) was used. The fine dashed line graph (Comparative Example) represents the change in mass of organic material 106 when manganese tetroxide (MnO) was used. The thin solid line graph (Example) represents the change in mass of organic material 106 when manganese dioxide (MnO) was used. This thin solid line graph is the graph obtained in Example 1 above. The mass change is expressed as a relative value, with the mass at 200°C being 100%. The experimental conditions were the same as those in Example 1 above, under which the thin solid line graph was obtained, except that the decomposition-accelerating component used was different.

[0080] In both cases, the mass of organic material 106 decreased with increasing temperature, indicating the progress of thermal decomposition of organic material 106. However, the graphs for titanium oxide (dotted line), manganese elemental material (thick dashed line), manganese tetroxide oxide (fine dashed line), and manganese monoxide (coarse dashed line) show roughly the same trend as the graph for only organic material 106, shown by the thick solid line, and it is thought that these do not contribute to a decrease in the thermal decomposition temperature.

[0081] However, when copper (II) oxide (thin dashed line) and manganese dioxide (thin solid line) were used, behavior significantly different from the change in mass of organic material 106 shown by the thick solid line was observed. Specifically, when copper (II) oxide (thin dashed line) was used, the mass rapidly decreased as the temperature rose to around 350°C. Then, at around 400°C, the mass reached almost 0%. When manganese dioxide (thin solid line) was used, the mass rapidly decreased as the temperature rose above 250°C, reaching almost 0%. Thereafter, the mass remained almost zero. Therefore, it can be said that by using manganese dioxide, the entire organic material 106 disappeared almost instantly.

[0082] As described above, when manganese dioxide, which also contains manganese, is compared with manganese alone, manganese monoxide, and manganese trimanganese tetroxide, a large difference in the shape of the graph was found. Therefore, it was found that simply containing manganese does not necessarily mean that the material can be thermally decomposed at a low temperature of, for example, about 250°C (for example, 400°C or less), and that it is only by using manganese dioxide that the effect of being thermally decomposable at about 250°C (for example, 400°C or less, preferably 350°C or less, more preferably 300°C or less) is achieved. [Explanation of symbols]

[0083] 1 Reaction vessel 101 Composite materials 102 Degradation accelerating components 103 Gas 104 Exhaust Gas 105 Inorganic materials 106 Organic materials 107 One Piece 2 Heating mechanism 200 Manufacturing equipment 3 Supply port 4 Outlet 5 Stirring mechanism 6 Separation mechanism S1 Contact process S2 Atmosphere control process S3 heating process S31 Preheating process S32 Main heating process

Claims

1. The method includes a heating step of heating an integrated product in which a composite material including an inorganic material composed of an inorganic substance and an organic material composed of an organic substance is contacted with a decomposition-promoting component that promotes thermal decomposition of the organic material, The decomposition-promoting component contains manganese dioxide as a main component. A method for producing an inorganic material, comprising:

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

3. The method for producing an inorganic material according to claim 1, The heating step is carried out at a temperature of 250° C. or higher and 400° C. or lower. A method for producing an inorganic material, comprising:

4. The method for producing an inorganic material according to claim 1, The content of the manganese dioxide is 100% by mass or more relative to the mass of the organic material. A method for producing an inorganic material, comprising:

5. The method for producing an inorganic material according to claim 1, The organic material includes a thermosetting resin. A method for producing an inorganic material, comprising:

6. The method for producing an inorganic material according to claim 1, The heating step is carried out in an oxidizing atmosphere. A method for producing an inorganic material, comprising:

7. The method for producing an inorganic material according to claim 6, The oxidizing atmosphere is a gas containing oxygen and having a hydrogen content of 0.01% by volume or less. A method for producing an inorganic material, comprising:

8. The method for producing an inorganic material according to claim 1, The decomposition-promoting component is in a powder form, The powdered decomposition-promoting component is brought into contact with the composite material. A method for producing an inorganic material, comprising:

9. The method for producing an inorganic material according to claim 1, The heating step is carried out in the gas phase. A method for producing an inorganic material, comprising:

10. The method for producing an inorganic material according to claim 1, The heating step is carried out while the integrated body is subjected to at least one of vibration and stirring. A method for producing an inorganic material, comprising:

11. The method for producing an inorganic material according to claim 1, a contacting step of contacting the composite material with the decomposition-promoting component inside a container, The heating step is carried out in the same vessel used in the contacting step. A method for producing an inorganic material, comprising:

12. a container for containing a composite material including an inorganic material composed of an inorganic substance and an organic material composed of an organic substance, and a decomposition-promoting component for promoting the thermal decomposition of the organic material; a heating mechanism for heating the inside of the container; a supply port for supplying a fluid into the container; a discharge port for discharging the fluid inside the storage tank from the storage tank, The decomposition-promoting component contains manganese dioxide as a main component. An inorganic material manufacturing apparatus characterized by:

13. The inorganic material manufacturing apparatus according to claim 12, Further, a separation mechanism for separating the inorganic material from the inside of the storage tank is provided. An inorganic material manufacturing apparatus characterized by:

14. The method includes a heating step of heating an integrated product in which a composite material including an inorganic material composed of an inorganic substance and an organic material composed of an organic substance is contacted with a decomposition-promoting component that promotes thermal decomposition of the organic material, The decomposition-promoting component contains manganese dioxide as a main component. A method for decomposing a composite material, comprising:

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