Composite particles

Abstract

To provide composite particles that can efficiently generate ammonia. [Solution] The present invention provides composite particles in which an ammonia-generating compound is supported on a carrier, wherein the carrier is at least one selected from the group consisting of silicon carbide, alumina, titania, silica, zirconia, ceria, silica-alumina, calcia, magnesia, and carbon black, and the ammonia-generating compound is a compound that generates ammonia upon heating, is insoluble in perfluorohexane, and has a specific gravity lower than that of perfluorohexane at 20°C.

Description

[Technical Field]

[0001] This disclosure relates to composite particles. [Background technology]

[0002] Patent Document 1 describes a method of decomposing a reducing agent, such as urea, which is a nitrogen-containing compound that is solid at room temperature and pressure, into a reducing agent decomposition catalyst such as alumina or silica by contacting the reducing agent with a heated gas (such as air) containing water vapor. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-15739 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the contact between reducing agents such as urea, which are solid nitrogen-containing compounds at room temperature and pressure, and reducing agent decomposition catalysts such as alumina and silica was insufficient, resulting in inefficient conversion to ammonia. Therefore, heating the reducing agent decomposition catalyst to 250°C to 500°C was a challenge.

[0005] This disclosure aims to provide composite particles that can efficiently generate ammonia. [Means for solving the problem]

[0006] According to the present disclosure, there is provided a composite particle in which an ammonia-generating compound is supported on a carrier, the carrier being at least one selected from the group consisting of silicon carbide, alumina, titania, silica, zirconia, ceria, silica alumina, calcia, magnesia, and carbon black, and the ammonia-generating compound being a compound that generates ammonia upon heating, being insoluble in perfluorohexane, and having a specific gravity smaller than the specific gravity of perfluorohexane at 20 °C.

[0007] According to this composite particle, since the ammonia-generating compound and the carrier are always in contact with each other, the conversion of the ammonia-generating compound to ammonia by heating is efficiently performed, and ammonia can be sufficiently generated even at 200 °C or lower.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide composite particles capable of efficiently generating ammonia.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a graph showing the NH3 absorbance with respect to the heating time. [Figure 2] FIG. 2 is a graph showing the NH3 absorbance with respect to the heating temperature. [Figure 3] FIG. 3 is a schematic diagram showing a state in which the entire amount of the carrier introduced into perfluorohexane has sunk in the liquid. [Figure 4] FIG. 4 is a schematic diagram showing a state in which the entire amount of the ammonia-generating compound introduced into perfluorohexane has floated on the liquid surface. [Figure 5] FIG. 5 is a schematic diagram showing a state in which a part of the composite particles introduced into perfluorohexane has floated on the liquid surface and the remaining part has sunk in the liquid. [Figure 6] FIG. 6 is a schematic diagram showing a state in which the entire amount of the composite particles introduced into perfluorohexane has floated on the liquid surface. [Figure 7] Figure 7 is a schematic diagram showing a state in which the entire amount of the composite particles introduced into perfluorohexane has sunk in the liquid.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, specific embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0011] 1. Composite Particles The composite particles of the present disclosure contain an ammonia-generating compound and a carrier.

[0012] The carrier is at least one selected from the group consisting of silicon carbide, alumina, titania, silica, zirconia, ceria, silica alumina, calcia, magnesia, and carbon black. Any of the carriers contained in the composite particles of the present disclosure is insoluble in perfluorohexane and has a specific gravity greater than the specific gravity of perfluorohexane at 20°C. Therefore, when only the carrier is introduced into perfluorohexane at 20°C, the entire amount of the introduced carrier sinks in the liquid (see Figure 3).

[0013] As the carrier, at least one selected from the group consisting of silicon carbide, alumina, titania, silica, and carbon black is preferable because ammonia can be generated more efficiently, and at least one selected from the group consisting of silicon carbide and silica is more preferable.

[0014] The BET specific surface area of the carrier is preferably 5 to 300 m 2 / g, more preferably 15 m 2 / g or more, still more preferably 25 m 2 / g or more, even more preferably 35 m 2 / g or more, particularly preferably 50 m 2 / g or more, more preferably 250 m 2 / g or less, still more preferably 200 m2 It is below / g, and more preferably 150 m 2 It is below / g, particularly preferably 100 m 2 It is below / g. In particular, when the BET specific surface area of the carrier is within the above range, there is a tendency for it to be easier to balance the ammonia generation efficiency and the handling property of the composite particles at a high level.

[0015] The BET specific surface area of the carrier can be calculated by the BET method using a specific surface area measuring device. The BET method is a method of measuring the amount of gas (nitrogen gas) physically adsorbed on the particle surface when the particles are in a low-temperature state and calculating the specific surface area. For the measurement of the BET specific surface area, Macsorb HM-1208 manufactured by Mountech Co., Ltd. was used.

[0016] The bulk density of the carrier is preferably 0.01 g / cm 3 or more, more preferably 0.03 g / cm 3 or more, still more preferably 0.05 g / cm 3 or more, preferably 1.00 g / cm 3 or less, more preferably 0.80 g / cm 3 or less.

[0017] The bulk density of the carrier is obtained by collecting W (g) of the carrier particles as a measurement sample, allowing this measurement sample to naturally fall into a graduated cylinder, gently shaking it to make the apparent volume V (cm 3 ) constant, measuring its mass and volume, and calculating based on the following formula. Bulk density (g / cm 3 ) = mass of measurement sample [W (g)] / volume of measurement sample [V (cm 3 )]

[0018] The ammonia-generating compound contained in the composite particles of this disclosure is insoluble in perfluorohexane and has a specific gravity lower than that of perfluorohexane at 20°C. Therefore, when only the ammonia-generating compound is added to perfluorohexane at 20°C, the entire amount of the added ammonia-generating compound floats on the surface of the liquid (see Figure 4).

[0019] In the composite particles of this disclosure, the ammonia-generating compound is supported on a carrier. In this disclosure, if the particles are placed in perfluorohexane adjusted to a temperature of 20°C, the perfluorohexane is stirred for 1 minute, and after sufficient standing, the particles are not separated in the perfluorohexane, then it can be said that the ammonia-generating compound is supported on the carrier.

[0020] If the ammonia-generating compound is not supported on a carrier, but merely in contact with the carrier, some of the particles introduced into perfluorohexane will float on the surface, while the rest of the particles will sink into the liquid (see Figure 5).

[0021] On the other hand, in the case of composite particles in which the ammonia-generating compound is supported on a carrier, the entire amount of composite particles introduced into perfluorohexane will either float on the surface of the liquid or sink (see Figures 6 and 7). The buoyancy or sinking of the composite particles is determined by the ratio of the ammonia-generating compound to the carrier within the composite particles.

[0022] The ammonia-generating compound contained in the composite particles of this disclosure is a compound that generates ammonia upon heating. In the composite particles of this disclosure, the ammonia-generating compound is supported on a carrier. Therefore, by heating the composite particles of this disclosure, ammonia can be generated more efficiently than when only the ammonia-generating compound is heated.

[0023] In one embodiment, by heating the composite particles of the present disclosure, a larger amount of ammonia can be generated than when heating only the ammonia-generating compound, even if the heating temperature and heating time are the same.

[0024] In one embodiment, the amount of ammonia generated when the composite particles are heated at 180°C for 30 minutes is 1.1 times or more the amount of ammonia generated when only the ammonia-generating compound is heated at 180°C for 30 minutes. The amount of ammonia generated when the composite particles are heated at 180°C for 30 minutes may be 1.3 times or more, 1.5 times or more, 1.7 times or more, 1.9 times or more, 2.1 times or more, or 2.3 times or more, and may be 5.0 times or less, 4.5 times or less, 4.0 or less, or 3.5 times or less, compared to the amount of ammonia generated when only the ammonia-generating compound is heated at 180°C for 30 minutes. In this way, by heating the composite particles of this disclosure, a larger amount of ammonia can be generated compared to heating only the ammonia-generating compound.

[0025] In one embodiment, by heating the composite particles of the present disclosure at a lower temperature than when heating only the ammonia-generating compound, it is possible to generate the same or greater amount of ammonia compared to when heating only the ammonia-generating compound. In one embodiment, by heating the composite particles of the present disclosure at a temperature 20°C or more lower than when heating only the ammonia-generating compound, it is possible to generate the same or greater amount of ammonia compared to when heating only the ammonia-generating compound.

[0026] In one embodiment, the ammonia generation temperature of the composite particles is 70 to 300°C. Preferably, the ammonia generation temperature of the composite particles is 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and still more preferably 110°C or higher. Furthermore, even when the composite particles of this disclosure are heated to a low temperature range of 180°C or lower, 170°C or lower, 160°C or lower, or 150°C or lower, a sufficient amount of ammonia is generated from the composite particles of this disclosure.

[0027] As described above, by heating the composite particles of this disclosure, it is possible to generate a larger amount of ammonia than when heating only the ammonia-generating compound, or to generate the same or greater amount of ammonia at a lower temperature. In other words, the composite particles of this disclosure can efficiently generate ammonia.

[0028] The average particle diameter of the composite particles of this disclosure is preferably 0.01 to 200 μm, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, more preferably 150 μm or less, and even more preferably 100 μm or less. The average particle diameter of the composite particles is the median diameter determined by a laser diffraction particle size distribution analyzer. When the average particle diameter of the composite particles is within the above range, it tends to be easier to achieve a high level of balance between ammonia generation efficiency and the handlingability of the composite particles.

[0029] The content of the ammonia-generating compound in the composite particles of this disclosure is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 8% by mass or more, even more preferably 10% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 50% by mass or less, in order to generate ammonia more efficiently.

[0030] When the carrier is silicon carbide, the content of the ammonia-generating compound in the composite particles of this disclosure is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, even more preferably 10% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 30% by mass or less, based on the total mass of the ammonia-generating compound and the carrier, in order to generate ammonia more efficiently.

[0031] When the carrier is silica, the content of the ammonia-generating compound in the composite particles of this disclosure is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 50% by mass or less, and still more preferably 30% by mass or less, based on the total mass of the ammonia-generating compound and the carrier, in order to generate ammonia more efficiently.

[0032] When the carrier is carbon black, the content of the ammonia-generating compound in the composite particles of this disclosure is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, preferably 90% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, relative to the total mass of the ammonia-generating compound and the carrier, in order to generate ammonia more efficiently.

[0033] The melting point of the ammonia-generating compound is preferably 100 to 350°C, more preferably 120°C or higher, and more preferably 340°C or lower. In particular, by using an ammonia-generating compound that is solid below 100°C, the ammonia-generating compound can remain stable in the composite particles even when the composite particles are stored for a long period of time, improving the handling of the composite particles.

[0034] As the ammonia-generating compound, at least one selected from urea, acetylurea, biuret, inorganic ammonium salts, N-phenylbenzamidine, and guanidines is preferred, more preferably at least one selected from urea, inorganic ammonium salts, and guanidines, and even more preferably urea, as it can generate ammonia more efficiently.

[0035] Examples of guanidines include phenylguanidine, diphenylguanidine, cyanoguanidine, guanidine hydrochloride, and guanidine carbonate. An example of an inorganic ammonium salt is ammonium chloride.

[0036] The composite particles of this disclosure can efficiently generate ammonia when heated, and therefore can be suitably used in applications where efficient ammonia generation during use is required. The composite particles of this disclosure can be suitably used, for example, as a polymer additive or fertilizer.

[0037] 2. Method for manufacturing composite particles The composite particles of this disclosure can be manufactured by a manufacturing method that involves supporting an ammonia-generating compound on a carrier, for example, using a thermal plasma method, an impregnation-supported method, or a mechanical particle composite method.

[0038] One method for producing composite particles using the thermal plasma method is to supply a carrier into a thermal plasma flame to put the carrier into a gas phase state, rapidly cool the carrier in the gas phase state by supplying a cooling gas toward the terminal end of the thermal plasma flame to generate primary carrier particles, and then supply an ammonia-generating compound to the primary carrier particles to support the ammonia-generating compound on the primary carrier particles.

[0039] The temperature of the thermal plasma flame must be higher than the boiling point of the carrier. For example, the temperature of the thermal plasma flame can be set to 6000°C. The atmospheric pressure of the thermal plasma flame is preferably below atmospheric pressure, for example, 0.5 to 100 kPa. The shape of the carrier supplied into the thermal plasma flame is preferably in powder form. The supply of the ammonia-generating compound to the primary fine particles can be carried out, for example, by spraying an aqueous solution of the ammonia-generating compound onto the primary fine particles. The aqueous solution of the ammonia-generating compound is preferably sprayed into an atmosphere in which the ammonia-generating compound does not thermally decompose. The droplets containing the sprayed ammonia-generating compound come into contact with the primary fine particles, the solvent then evaporates, and the ammonia-generating compound precipitates on the primary fine particles.

[0040] One method for producing composite particles using the impregnation-supporting method involves adding a support to a solution of an ammonia-generating compound and evaporating the solvent to support the ammonia-generating compound on the support. The solution of the ammonia-generating compound is preferably an aqueous solution. The solvent is preferably water.

[0041] The mechanical particle compounding method is a method of producing composite particles by applying mechanical forces such as compressive force, shear force, frictional force, and impact force while mixing an ammonia-generating compound with a carrier, thereby coating the surface of the carrier with the ammonia-generating compound. For example, one method is to mix the ammonia-generating compound and the carrier while crushing them using a mortar and pestle. In a method in which the ammonia-generating compound and carrier are placed in a bag and the bag is shaken, no mechanical force is applied to the ammonia-generating compound or the carrier, so the ammonia-generating compound cannot be supported on the carrier.

[0042] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims.

[0043] <1> According to the first aspect of this disclosure, A composite particle in which an ammonia-generating compound is supported on a carrier, The carrier is at least one selected from the group consisting of silicon carbide, alumina, titania, silica, zirconia, ceria, silica-alumina, calcia, magnesia, and carbon black. The ammonia-generating compound is a compound that generates ammonia upon heating, is insoluble in perfluorohexane, and has a specific gravity lower than that of perfluorohexane at 20°C. Composite particles are provided. <2> According to the second aspect of this disclosure, A composite particle is provided in which, when the composite particle is heated at 180°C for 30 minutes, the amount of ammonia generated is 1.1 times or more the amount of ammonia generated when only the ammonia-generating compound is heated at 180°C for 30 minutes. <3> According to the third aspect of this disclosure, A composite particle is provided in which the content of the ammonia-generating compound in the composite particle is 1% by mass or more, relative to the total mass of the ammonia-generating compound and the carrier. <4> According to the fourth aspect of this disclosure, The present invention provides composite particles from any of the first to third viewpoints, wherein the ammonia generation temperature of the composite particles is 70 to 300°C. <5> According to the fifth aspect of this disclosure, A composite particle is provided, wherein the melting point of the ammonia-generating compound is 100 to 350°C, according to any of the first to fourth viewpoints. <6> According to the sixth aspect of this disclosure, A composite particle is provided in any of the first to fifth aspects, wherein the ammonia-generating compound is at least one selected from urea, acetylurea, biuret, N-phenylbenzamidine, and guanidines. <7> According to the seventh aspect of this disclosure, The BET specific surface area of ​​the carrier is 5 to 300 m². 2 A composite particle is provided that is 1 to 6 in any of the six aspects, with a value of / g. <8> According to the eighth aspect of this disclosure, A composite particle according to any of the first to seventh aspects is provided, obtained by a manufacturing method in which the ammonia-generating compound is supported on the carrier using a thermal plasma method, an impregnation support method, or a mechanical particle composite method. [Examples]

[0044] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to such embodiments.

[0045] Preparation Example 1 In Preparation Example 1, silicon carbide particles with a particle size of approximately 2-3 μm were used as raw materials and supplied into a thermal plasma flame using a powder feeder. The input to the high-frequency oscillation coil for generating the thermal plasma flame was kept constant at 50 kW, and the pressure inside the plasma torch was fixed at 40 kPa. Argon gas and hydrogen gas were used as the plasma gas, with the argon gas flow rate set to 210 liters / min (standard conditions) and the hydrogen gas flow rate to 15 liters / min (standard conditions). Argon gas was used as the cooling gas, with the argon gas flow rate set to 400 liters / min (standard conditions). Urea was used as the ammonia-generating compound, and water was used as the solvent. An aqueous solution containing urea (urea concentration 25.0 W / W%) was sprayed onto the primary silicon carbide particles using a spray gas from a region where the urea does not thermally decompose. Argon gas was used as the spray gas. The urea used was manufactured by Fujifilm Wako Pure Chemical Industries (melting point 132-136°C, specific gravity 1.335).

[0046] Preparation Example 2 In Preparation Example 2, the only difference from Preparation Example 1 was that methane gas was added to the argon gas used as the cooling gas, and the flow rate of the methane gas was set to 0.5 liters / minute.

[0047] Evaluation of ammonia generation 1 The samples (composite particles prepared in Preparation Example 1 and urea from Comparative Example 3) were placed in the reactor, and while flowing a gas adjusted to an oxygen concentration of 20 vol% and a nitrogen concentration of 80 vol% at a rate of 10 cc / min, the temperature inside the reactor was raised from room temperature to 180°C, and then the samples were heated at 180°C for a predetermined time. The ammonia generated by heating was measured using a Fourier transform infrared spectrophotometer (FT-IR). The amount of ammonia generated was evaluated using a wavenumber of 966 cm⁻¹. -1 Absorbance was used. Figure 1 shows the ammonia generation behavior with respect to heating time per 2 mg of urea. The heating time shown in Figure 1 is defined as the time when the temperature inside the reactor reaches 180°C, with 0 minutes being the starting point. If ammonia is generated from the sample before the temperature inside the reactor reaches 180°C, the NH3 absorbance will exceed 0 even at the point when the heating time is 0 minutes.

[0048] As shown in Figure 1, when composite particles of urea and silicon carbide are heated at 180°C, more ammonia is generated than when urea alone is used.

[0049] Evaluation of ammonia generation amount 2 The samples (composite particles prepared in Preparation Example 1 and urea from Comparative Example 3) were placed in the reactor, and the reactor was heated at a heating rate of 4°C / min while flowing a gas adjusted to an oxygen concentration of 20 vol% and a nitrogen concentration of 80 vol% at a rate of 10 cc / min. The ammonia generated by heating was measured using a Fourier transform infrared spectrophotometer (FT-IR). The amount of ammonia generated was evaluated using a wavenumber of 966 cm⁻¹. -1 The absorbance was used. Figure 2 shows the ammonia evolution behavior with respect to heating temperature per 2 mg of urea.

[0050] As shown in Figure 2, when comparing the composite particles of urea and silicon carbide (Preparation Example 1) with urea alone, a difference in NH3 absorbance between the two begins to be observed at 80°C. Compared to the absorbance of urea alone, the NH3 absorbance of the composite particles is approximately 3 times higher at 100°C, approximately 15 times higher at 120°C, and approximately 25 times higher at 140°C. Therefore, it can be seen that heating the composite particles of urea and silicon carbide at a temperature 20°C or more lower than that of heating urea alone can generate the same or more ammonia than heating urea alone.

[0051] Immersion test of particles in perfluorohexane 30 ml of perfluorohexane (manufactured by Tokyo Chemical Industry Co., Ltd., specific gravity 1.69) was poured into a 50 ml glass screw tube, 100 mg of particles were added, and the mixture was stirred for 1 minute at 270 rpm using a magnetic stirrer. After standing for 30 minutes, the separation state was visually observed and evaluated according to the following criteria. Y: As shown in Figure 5, some of the particles were floating on the liquid surface, while some of the particles were submerged in the liquid. N: As shown in Figure 6, the entire amount of particles was floating on the liquid surface, or as shown in Figure 7, the entire amount of particles was submerged in the liquid. If the entire volume of particles floats on the liquid surface, or if the entire volume of particles sinks in the liquid, then it can be said that the ammonia-generating compound is supported on the carrier.

[0052] Weight loss rate of ammonia-generating compounds when heated at 180°C for 30 minutes The initial weight of the sample (particles) was weighed using an analytical balance (product name: AUX220 (manufactured by Shimadzu Corporation)), and then the sample was heated in a 180°C oven for 30 minutes. After heating, the weight was weighed again using an analytical balance (product name: AUX220 (manufactured by Shimadzu Corporation)). The weight loss rate (mass %) was calculated using the following formula. Weight reduction rate (%)=(AB) / A A = Initial weight of particles (g) × Ammonia-generating compound content in composite particles (mass%) / 100) B = Weight of particles after heating at 180°C for 30 minutes (g) - Initial weight of particles (g) × Content of carrier in composite particles (mass%) / 100)

[0053] Furthermore, the weight reduction factor of the particles was calculated using the following formula. Weight reduction ratio=D / E D = Weight loss rate of ammonia-evolving compounds in composite particles (%) E = Weight loss rate of ammonia-generating compounds contained in the composite particles (%) (The weight loss percentage of E is as shown in Comparative Examples 3-5 in Table 1.) The weight loss ratio is the ratio of the amount of ammonia generated when the composite particles are heated at 180°C for 30 minutes to the amount of ammonia generated when only the ammonia-generating compound is heated at 180°C for 30 minutes. The more efficiently the composite particles generate ammonia, the greater the weight loss ratio. In other words, the ammonia generation efficiency of the composite particles can be determined from the weight loss ratio.

[0054] Example 1 The weight loss rate of urea in the composite particles prepared in Preparation Example 1 was measured when heated at 180°C for 30 minutes. Furthermore, the separation state of these particles in perfluorohexane was confirmed.

[0055] Example 2 The weight loss rate of urea in the composite particles prepared in Preparation Example 2 was measured when heated at 180°C for 30 minutes. Furthermore, the separation state of these particles in perfluorohexane was confirmed.

[0056] Example 3 Urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as an ammonia-generating compound and silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as a support were weighed in a weight ratio of 10:90 and thoroughly mixed using a mortar and pestle until homogenized to prepare composite particles. The weight loss rate of urea was measured when these composite particles were heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0057] Example 4 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02271) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071). The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0058] Example 5 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (NMSiC99, manufactured by Nanomakers) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silicon carbide were weighed in a weight ratio of 90:10. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0059] Example 6 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (NMSiC99, manufactured by Nanomakers, Inc.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silicon carbide were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0060] Example 7 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (NMSiC99, manufactured by Nanomakers, Inc.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silicon carbide were weighed in a weight ratio of 50:50. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0061] Example 8 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (NMSiC99, manufactured by Nanomakers, Inc.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silicon carbide were weighed in a weight ratio of 30:70. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0062] Example 9 Composite particles were prepared in the same manner as in Example 3, except that silicon carbide (NMSiC99, manufactured by Nanomakers, Inc.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silicon carbide were weighed in a weight ratio of 10:90. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0063] Example 10 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 90:10. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0064] Example 11 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0065] Example 12 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 50:50. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0066] Example 13 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 30:70. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0067] Example 14 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 10:90. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0068] Example 15 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL OX50, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0069] Example 16 Composite particles were prepared in the same manner as in Example 3, except that silica (AEROSIL 130, manufactured by Nippon Aerosil Co., Ltd.) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0070] Example 17 Composite particles were prepared in the same manner as in Example 3, except that silica (Rheorosil CP-102, manufactured by Tokuyama Corporation) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0071] Example 18 Composite particles were prepared in the same manner as in Example 3, except that silica (RheoroSeal QS-102, manufactured by Tokuyama Corporation) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0072] Example 19 Composite particles were prepared in the same manner as in Example 3, except that silica (RheoroSeal QS-30, manufactured by Tokuyama Corporation) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and urea and silica were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0073] Example 20 Composite particles were prepared in the same manner as in Example 3, except that carbon black (Cancarb, THERMAX N990) was used instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071) as the support, and urea and carbon black were weighed in a weight ratio of 90:10. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0074] Example 21 Composite particles were prepared in the same manner as in Example 3, except that carbon black (Cancarb, THERMAX N990) was used instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071) as the support, and urea and carbon black were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0075] Example 22 Composite particles were prepared in the same manner as in Example 3, except that carbon black (Cancarb, THERMAX N990) was used instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071) as the support, and urea and carbon black were weighed in a weight ratio of 50:50. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0076] Example 23 Composite particles were prepared in the same manner as in Example 3, except that carbon black (Cancarb, THERMAX N990) was used instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071) as the support, and urea and carbon black were weighed in a weight ratio of 30:70. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0077] Example 24 Composite particles were prepared in the same manner as in Example 3, except that carbon black (Cancarb, THERMAX N990) was used instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071) as the support, and urea and carbon black were weighed in a weight ratio of 10:90. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0078] Example 25 Composite particles were prepared in the same manner as in Example 3, except that alumina (AKP-G07, Sumitomo Chemical Co., Ltd.) was used as the support instead of silicon carbide (02071, Nisshin Engineering Co., Ltd.), and urea and alumina were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0079] Example 26 Composite particles were prepared in the same manner as in Example 3, except that titania (Sakai Chemical Industry Co., Ltd., R-5N) was used as the support instead of silicon carbide (Nisshin Engineering Co., Ltd., 02071), and urea and titania were weighed in a weight ratio of 80:20. The weight loss rate of urea was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0080] Example 27 Composite particles were prepared in the same manner as in Example 3, except that 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silicon carbide (manufactured by Nanomakers, NMSiC99) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and 1,3-diphenylguanidine and silicon carbide were weighed in a weight ratio of 80:20. The weight loss rate of 1,3-diphenylguanidine was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0081] Example 28 Composite particles were prepared in the same manner as in Example 3, except that 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silicon carbide (manufactured by Nanomakers, NMSiC99) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and 1,3-diphenylguanidine and silicon carbide were weighed in a weight ratio of 70:30. The weight loss rate of 1,3-diphenylguanidine was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0082] Example 29 Composite particles were prepared in the same manner as in Example 3, except that 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was used as the ammonia-generating compound instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335), silicon carbide (manufactured by Nanomakers, NMSiC99) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and 1,3-diphenylguanidine and silicon carbide were weighed in a weight ratio of 50:50. The weight loss rate of 1,3-diphenylguanidine was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0083] Example 30 Composite particles were prepared in the same manner as in Example 3, except that 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silicon carbide (manufactured by Nanomakers, NMSiC99) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and 1,3-diphenylguanidine and silicon carbide were weighed in a weight ratio of 20:80. The weight loss rate of 1,3-diphenylguanidine was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0084] Example 31 Composite particles were prepared in the same manner as in Example 3, except that 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was used as the ammonia-generating compound instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335), silicon carbide (manufactured by Nanomakers, NMSiC99) was used as the support instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071), and 1,3-diphenylguanidine and silicon carbide were weighed in a weight ratio of 10:90. The weight loss rate of 1,3-diphenylguanidine was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0085] Example 32 Composite particles were prepared in the same manner as in Example 3, except that ammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 338°C, specific gravity 1.53) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silica (manufactured by Nippon Aerosil Co., Ltd., AEROSIL 50) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and ammonium chloride and silica were weighed in a weight ratio of 80:20. The weight loss rate of ammonium chloride was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0086] Example 33 Composite particles were prepared in the same manner as in Example 3, except that ammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 338°C, specific gravity 1.53) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silica (manufactured by Nippon Aerosil Co., Ltd., AEROSIL 50) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and ammonium chloride and silica were weighed in a weight ratio of 50:50. The weight loss rate of ammonium chloride was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0087] Example 34 Composite particles were prepared in the same manner as in Example 3, except that ammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 338°C, specific gravity 1.53) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silica (manufactured by Nippon Aerosil Co., Ltd., AEROSIL 50) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and ammonium chloride and silica were weighed in a weight ratio of 20:80. The weight loss rate of ammonium chloride was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0088] Example 35 Composite particles were prepared in the same manner as in Example 3, except that ammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 338°C, specific gravity 1.53) was used instead of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as the ammonia-generating compound, and silica (manufactured by Nippon Aerosil Co., Ltd., AEROSIL 50) was used instead of silicon carbide (manufactured by Nisshin Engineering Co., Ltd., 02071) as the support, and ammonium chloride and silica were weighed in a weight ratio of 10:90. The weight loss rate of ammonium chloride was measured when heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0089] Comparative Example 1 Urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) as an ammonia-generating compound and silicon carbide (manufactured by Nanomakers, NMSiC99) as a support were weighed in a 10:90 ratio and placed in a polyethylene bag. The mixture was then mixed by shaking the polyethylene bag. The weight loss rate of the urea was measured when the mixed particles were heated at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0090] Comparative Example 2 Mixed particles were prepared in the same manner as in Comparative Example 1, except that urea and silicon carbide were weighed in a weight ratio of 30:70. The weight loss rate of urea was measured after heating at 180°C for 30 minutes. Furthermore, the separation state in perfluorohexane was confirmed.

[0091] Comparative Example 3 The weight loss rate of urea (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., melting point 132-136°C, specific gravity 1.335) was measured when heated at 180°C for 30 minutes.

[0092] Comparative Example 4 The weight loss rate of 1,3-diphenylguanidine (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 147°C, specific gravity 1.13) was measured when heated at 180°C for 30 minutes.

[0093] Comparative Example 5 The weight loss rate of ammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd., melting point 338°C, specific gravity 1.53) was measured when heated at 180°C for 30 minutes.

[0094] Table 1 shows the weight loss rate of the ammonia-generating compound and the separation state in perfluorohexane when heated at 180°C for 30 minutes in each example and comparative example. The content of each component in the composite particles of Examples 1 and 2 was determined by Rietveld analysis. Aeris from Spectris Corporation was used for the Rietveld analysis. From Table 1, it was confirmed that the particles produced by the thermal plasma method and the mechanical particle composite method showed a greater weight loss rate of the ammonia-generating compound and a greater amount of ammonia generation compared to the particles mixed in a bag or the ammonia-generating compound alone. Furthermore, separation of the ammonia-generating compound and the carrier was not observed in perfluorohexane for the particles produced by the thermal plasma method and the mechanical particle composite method, but separation was observed for the particles mixed in a bag.

[0095] The physical properties of each component listed in Table 1 are shown below.

[0096] Ammonia-producing compounds Urea: Melting point 132-136°C, specific gravity 1.335 1,3-Diphenylguanidine: Melting point 147°C, specific gravity 1.13 Ammonium chloride: Melting point 338°C, specific gravity 1.53

[0097] Carrier Silicon carbide (1): Manufactured by Nisshin Engineering Co., Ltd., 02071, BET specific surface area 71 m² 2 / g Silicon carbide (2): Manufactured by Nisshin Engineering Co., Ltd., 02271, BET specific surface area 75 m² 2 / g Silicon carbide (3): Nanomakers, NMSiC99, BET specific surface area 55 m² 2 / g Silica (1): Manufactured by Nippon Aerosil Co., Ltd., AEROSIL 50, BET specific surface area 50 m² 2 / g Silica (2): Manufactured by Nippon Aerosil Co., Ltd., AEROSIL OX50, BET specific surface area 50 m² 2 / g Silica (3): Manufactured by Nippon Aerosil Co., Ltd., AEROSIL 130, BET specific surface area 130 m² 2 / g Silica (4): Tokuyama Corporation, Rheoroseal CP-102, BET specific surface area 200 m² 2 / g Silica (5): Tokuyama Corporation, Rheoroseal QS-102, BET specific surface area 200 m² 2 / g Silica (6): Tokuyama Corporation, Rheoroseal QS-30BET, specific surface area 300m² 2 / g Carbon black: Cancarb, THERMAX N990, BET specific surface area 7 m² 2 / g Alumina: Sumitomo Chemical Co., Ltd., AKP-G07, BET specific surface area 80 m² 2 / g Titania: Manufactured by Sakai Chemical Industry Co., Ltd., R-5N, BET specific surface area 17m² 2 / g

[0098] [Table 1] [Explanation of symbols]

[0099] 11 Perfluorohexane 12 Carrier particles 13 Ammonia-evolving compounds 14 particles

Claims

1. A composite particle in which an ammonia-generating compound is supported on a carrier, The carrier is at least one selected from the group consisting of silicon carbide, alumina, titania, silica, zirconia, ceria, silica-alumina, calcia, magnesia, and carbon black. The ammonia-generating compound is a compound that generates ammonia upon heating, is insoluble in perfluorohexane, and has a specific gravity lower than that of perfluorohexane at 20°C. A composite particle characterized by the following features.

2. The composite particles according to claim 1, wherein the amount of ammonia generated when the composite particles are heated at 180°C for 30 minutes is 1.1 times or more the amount of ammonia generated when only the ammonia-generating compound is heated at 180°C for 30 minutes.

3. The composite particle according to claim 1 or 2, wherein the content of the ammonia-generating compound in the composite particle is 1% by mass or more with respect to the total mass of the ammonia-generating compound and the carrier.

4. The composite particle according to claim 1 or 2, wherein the ammonia generation temperature of the composite particle is 70 to 300°C.

5. The composite particle according to claim 1 or 2, wherein the melting point of the ammonia-generating compound is 100 to 350°C.

6. The composite particle according to claim 1 or 2, wherein the ammonia-generating compound is at least one selected from urea, acetylurea, biuret, inorganic ammonium salts, N-phenylbenzamidine, and guanidines.

7. The BET specific surface area of ​​the carrier is 5 to 300 m². ２ The composite particles according to claim 1 or 2, wherein the particle size is / g.

8. The composite particles according to claim 1 or 2, obtained by a manufacturing method in which the ammonia-generating compound is supported on the carrier using a thermal plasma method, an impregnation support method, or a mechanical particle composite method.

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