JPWO2014057564A1 - Manufacturing method of coated material using freeze-drying method - Google Patents

Abstract

The method for producing a dried nanoparticle includes a step of producing a dispersion in which nanoparticles are dispersed in an organic solvent, and a lyophilization step of lyophilizing the dispersion to remove the organic solvent.

Description

  The present invention relates to a method for producing a dried nanoparticle using a freeze-drying method.

  Conventionally, a dispersion (hereinafter referred to as a slurry) in which a powder is dispersed in a solvent has been dried by a method such as air drying, heating drying, or vacuum drying in a room temperature air atmosphere. Among these methods, air drying in a normal temperature air atmosphere is the simplest method, and the slurry is usually left in the air atmosphere, or the solvent is evaporated by applying a moderately strong wind to the slurry. A dry powder can be obtained. Further, the heat drying method is used as a method for promoting the transpiration of the solvent by increasing the temperature and realizing a higher degree of drying faster.

  The vacuum drying method is used as a method of promoting the transpiration of the solvent by placing the slurry under vacuum to realize a higher degree of dryness faster. In addition, about the heating at the time of air drying or vacuum drying, it is used suitably according to the objective, a sample, etc.

  Even when a method such as air drying, heating drying, or vacuum drying under a normal temperature air atmosphere is used, a dried particle can be obtained. However, when these drying methods are used, the concentration of particles increases with decreasing solvent and the proximity distance decreases, and eventually comes into contact. Usually, the particles are aggregated by the interaction between the particles as the concentration increases. This phenomenon is more pronounced as the particle size becomes smaller, particularly when the particle size is 1 μm or less.

  Therefore, the dried particle obtained by using these methods is strongly agglomerated and it is difficult to obtain the characteristics as the original particles. Therefore, it is necessary to perform distributed processing again at the time of use. At this time, generally, a method of crushing by applying an external force such as a mill or a roll is used. However, there is a problem that the particles are affected by destruction or deformation by the applied force. In addition, sufficient dispersibility cannot often be achieved even when such a force as to be affected is applied.

  In the case of a drying method involving heating, the particles may be affected by the structure and the like, and required characteristics may not be obtained.

  In addition, a method of removing a solvent from a solution in which nano-sized ultrafine particles are dissolved by freeze-drying is also used (see Patent Documents 2 and 3).

Japanese Patent No. 3005683 Japan Special Table 2008-538552 Japanese Unexamined Patent Publication No. 2009-138030

  The method of obtaining fine particles using the freeze-drying method is easy to implement and handle the fine particles as a product, and further application is expected in the future. On the other hand, the methods described in Patent Documents 2 and 3 use water and a dispersant in the process, and it has been found that the use of these may affect the performance of the dried nanoparticle as a product. .

  An object of this invention is to provide the manufacturing method of the nanoparticle dry body using the freeze-drying method which solved the trouble of the prior art.

  The present invention provides a method for producing a dried nanoparticle comprising: a step of producing a dispersion in which nanoparticles are dispersed in an organic solvent; and a freeze-drying step of lyophilizing the dispersion to remove the organic solvent. provide.

  For example, an organic solvent having a melting point of −30 ° C. to 30 ° C. is selected.

  For example, the organic solvent is t-butanol, cyclohexane, acetic acid, acetophenone, acetylacetone, 2-aminoethanol, aniline, benzaldehyde, benzyl alcohol, benzylbenzoate, cyclohexanol, diethylene glycol, diethylene glycol monoethyl ether acetate, dimethylacetamide, dimethyl sulfoxide. 1,4-dioxane, ethylene glycol, formamide, formic acid, glycerol, 2-methyl-2-butanol, nitrobenzene, 1-octanol, 3-pentanol, tetrachloroethylene, trifluoroacetic acid, xylene, or A mixture of two or more types.

  The organic solvent may contain water.

  For example, the nanoparticles are metals such as nickel, cobalt, silver, gold, platinum, copper, and aluminum. Moreover, the carbon material used as metal substitutes, such as a carbon nanotube, may be sufficient.

  The nanoparticle dry body manufactured by the manufacturing method of the nanoparticle dry body mentioned above is also contained in this invention.

  The present invention is a method for producing a dried nanoparticle using a freeze-drying method, and it can be dried while removing the solvent in a state where the dispersion structure (state) is fixed by freezing, thereby suppressing particle aggregation during the drying process. can do.

The graph which shows the particle size distribution obtained by the light-scattering method of the slurry 3 (before freeze-drying) of Example 1 The graph which shows the particle size distribution obtained by the light-scattering method of the slurry 5 (after freeze-drying) of Example 1 The graph which shows the particle size distribution obtained by the light-scattering method of the slurry 6 (after freeze-drying) of Example 2 The graph which shows the particle size distribution obtained by the light-scattering method of the slurry 7 (after freeze-drying) of Example 3 Graph showing the particle size distribution obtained by the light scattering method of slurry B of Comparative Example 2 (after lyophilization with water) It is the surface photograph of a coating film, (a) is a microscope picture of the coating film A by the slurry A of the comparative example 1, (b) is a microscope picture of the coating film 1 by the slurry 5 of Example 1. It is the surface photograph of a coating film, (a) is a microscope picture of the coating film by the slurry 6 of Example 2, (b) is a microscope picture of the coating film by the slurry B of the comparative example 2.

  Hereinafter, embodiments of the present invention will be described in detail.

  The present invention provides a method for producing a dried nanoparticle comprising: a step of producing a dispersion in which nanoparticles are dispersed in an organic solvent; and a freeze-drying step of lyophilizing the dispersion to remove the organic solvent. To do.

  That is, according to the method for producing a dried nanoparticle, a dispersion liquid in which nanoparticles having an average particle size of 1 μm or less are mainly dispersed in an organic solvent is exposed to a freeze-drying step, and the organic solvent is removed.

  The freeze-drying method in the freeze-drying step is a drying method in which the solvent is removed in a state where the structure of the object to be dried and the arrangement of the components are fixed, and has been mainly used for food applications. As noted, the scope of coverage is also expanding. The Applicant has also continued his research focusing on these unique characteristics of the freeze-drying method.

  Nanoparticles are generally very cohesive and it is difficult to achieve a dispersed state. Moreover, even if the dispersion state is once realized in the solvent, it reaggregates with the passage of time, and it is difficult to maintain the dispersion state as in the case of the dispersion.

  Furthermore, since it is desired to use various dispersing solvents depending on the application of the nanoparticles, it is often necessary to carry out laborious and costly processes such as solvent replacement in the initial slurry state. There is. Therefore, in order to obtain a slurry having a free composition depending on the application, supply in a dry powder state is suitable in many situations. However, at the time of drying, the slurry concentration increases due to the decrease in the solvent, the distance between particles is reduced, and the particles are dried through a state in which they are more likely to be aggregated. Since such a dry powder is agglomerated with a very strong force, it is difficult to redisperse in a solvent, which causes a problem that it is difficult to handle.

  On the other hand, according to the freeze-drying method, the slurry structure (state) is fixed while the nanoparticles are in a dispersed state, and only the solvent (organic solvent) is removed while being fixed, thereby suppressing the above-described problem. .

  In the freeze-drying method, water is usually used as a solvent. However, in the case of a material having a high surface activity such as a metal, when the water is used as a solvent, the surface of the material may be modified such as corrosion or oxidation. is there. Since changes in the composition and chemical state of the material surface greatly affect the properties of the material itself as well as the dispersibility, it is desirable to use an organic solvent rather than a highly active solvent such as water.

  Therefore, according to the present invention, an organic solvent is used as a dispersion solvent for dispersing nanoparticles. In addition, many organic solvents generally have a high vapor pressure, so that there is an advantage that drying becomes easy.

Conventionally, a method of using an additive such as a dispersing agent at the time of slurry preparation has been studied. However, since these additives such as dispersants are usually organic substances mainly composed of carbon, they act on materials and processes in the same way as organic contamination, resulting in deterioration of electrical properties and thermal processes. There is a problem that degassing occurs. On the other hand, in the present invention, as a rule, no dispersant is used at the time of slurry preparation due to the effect of freeze-drying, or the amount can be reduced more than usual. However, the use of a dispersant is not denied in the range that does not adversely affect the type of nanoparticles.
Here, the additive such as a dispersant is a compound added to obtain the dispersibility and stability of the nanoparticles in the slurry, and generally an amphiphilic substance such as a surfactant. Is given as an example.

  In addition, when an organic solvent is used, attention should be paid to its melting point. Many organic solvents have a melting point lower than that of water. However, if the melting point is too low, the freezing process may be hindered, for example, because it takes too long to freeze. In addition, since a solvent having a high melting point has a high boiling point, a solvent having an excessively high melting point may interfere with the drying process due to the fact that it takes too much time for sublimation. In addition, when the melting point is near or above room temperature, it becomes difficult to adjust slurry because it becomes solid at room temperature. In view of these, the organic solvent preferably has a melting point in the range of −30 to 30 ° C., more preferably in the range of −20 ° C. to 20 ° C., and still more preferably in the range of −10 ° C. to 10 ° C. It is in the range of ° C.

  Examples of organic solvents used while satisfying the above requirements are t-butanol (tertiary butyl alcohol), cyclohexane, acetic acid, acetophenone, acetylacetone, 2-aminoethanol, aniline, benzaldehyde, benzyl alcohol, benzylbenzoate, cyclohexanol, diethylene glycol , Diethylene glycol monoethyl ether acetate, dimethylacetamide, dimethyl sulfoxide, 1,4-dioxane, ethylene glycol, formamide, formic acid, glycerol, 2-methyl-2-butanol, nitrobenzene, 1-octanol, 3-pentanol, tetrachloroethylene, There are trifluoroacetic acid, xylene, and the like, and these are composed of one kind or a mixture of two or more kinds.

  The nanoparticles of the present invention are made of, for example, a metal. Since many metals are resistant to organic solvents, there is a greater degree of freedom in selecting a solvent that is more suitable for lyophilization. For example, among metals, nickel, cobalt, silver, gold, platinum, copper, aluminum and the like are used.

  Further, it is desirable that the temperature in the freeze-drying process is controlled to be equal to or lower than the melting point of the organic solvent to be used. This is because if the slurry temperature is equal to or higher than the melting point of the organic solvent at the stage where freeze-drying is not completed, vacuum drying occurs and aggregation is induced.

  Moreover, it is desirable that the processing container used in the freeze-drying process is pre-cooled to a temperature equal to or lower than the melting point of the organic solvent used in advance before the freeze-drying process. The time required for freezing is closely related to the effect of the invention, and it is desirable that the time required for freezing is short from the knowledge of the food field and the like that has been performed conventionally. This is because if the time required for freezing becomes longer, the nanoparticles settle and reagglomerate. Further, in the freezing stage, freezing is realized by cooling the slurry through the processing container by a cooler. In many cases, since the slurry is charged outside the cooled apparatus, a time from slurry charging to cooling is required. Therefore, it is expected to shorten the freezing time by pre-cooling the processing container.

  In addition, it is desirable that the freeze-drying step includes a step of bringing the slurry into contact with a gas or liquid cooled to a solvent melting point or lower. Usually, since the slurry is cooled from the contact surface with the processing container, freezing of the non-contact surface is delayed. However, by bringing into contact with the cooling gas or liquefied gas, cooling is performed also from the non-contact surface of the processing container, and freezing can proceed more rapidly. In addition, about a contact method, spraying, dripping, etc. are selected, However It does not specifically limit.

  As described above, the time required for freezing is closely related to the effect of the invention, and it is desirable that the time be shorter. Therefore, it is desirable that the time required for freezing is shorter than the reaggregation time of the particles in the slurry.

  The nanoparticle dry body manufactured by the manufacturing method of the nanoparticle dry body of this invention is also contained in this invention. The dried nanoparticle of the present invention has good handleability and can be applied to various fields. For example, Multi-Layer Ceramic Capacitors (MLCCs) are electronic devices that are expected to expand further in the future, but there is a strong demand for miniaturization and micronization of Ni nanoparticles that are used as materials. ing. The present invention can reliably meet such demands. Further, it can be applied to particles for inkjet ink, particles for battery electrodes, particles for transparent conductive films, dielectric particles, and the like.

  The present invention is a method for producing a dried nanoparticle using a freeze-drying method, and it can be dried while removing the solvent in a state where the dispersion structure (state) is fixed by freezing, thereby suppressing particle aggregation during the drying process. can do.

  According to the present invention, it is possible to obtain a dry powder in a dispersed state, so that it is easy to re-disperse in a solvent, and even if it is in an associated state of a plurality of particles, it is dried while the solvent is interposed. The binding force is extremely weak, and a redispersion state can be easily realized by stirring or ultrasonic irradiation.

  Further, since there is no treatment such as heating that may affect the particles, the particle characteristics can be maintained even after drying.

  Next, an embodiment of the implementation process of the present invention will be described. The nanoparticle dry body production technology according to the present invention includes the freeze-drying method described above. Here, “freeze-drying” means a drying method in which a target sample is frozen below the melting point of the solvent, and then the pressure is reduced while the sample temperature is kept below the melting point to sublimate the solvent. This is so-called freeze drying, which utilizes the property of lowering the boiling point of the solvent under reduced pressure, and is also referred to as “vacuum freeze drying” because of the method of drying under reduced pressure (vacuum) conditions.

  Various nanoparticles can be selected as the nanoparticles used in the production method according to the present invention, but those mainly composed of a metal material are used. For example, metal nanoparticles such as nickel, cobalt, silver, gold, platinum, copper, and aluminum are used.

  In addition, the shape of the nanoparticles is not particularly limited, and various shapes of nanoparticles can be appropriately selected depending on the application to be used. Further, surface treatment such as surface modification may be applied depending on the purpose of use.

  Next, in the production of the dried nanoparticle, it will be described in four parts: a slurrying process, a freezing process, a drying process, and a removing process.

<Slurry process>
This slurrying step corresponds to a step of producing a dispersion by dispersing the target nanoparticles in an organic solvent. Various distributed processes may be additionally performed, and a known distributed process may be used. It should be noted that the transition from the slurrying process to the below-described freezing process is preferably performed in as short a time as possible from the viewpoint of suppressing aggregation during storage.

  Specifically, a method of introducing nanoparticles into an organic solvent stirred with a known stirring device such as a stirring blade or a magnetic stirrer can be used. About the nanoparticle density | concentration in a slurry, it is possible to select suitably according to a use or the objective.

  Conventionally, a method using an additive such as a dispersant has been studied. However, since the dispersant is usually an organic substance mainly composed of carbon, it acts in the same manner as organic contamination in terms of materials and processes. In other words, there are problems such as deterioration of electrical characteristics and generation of degassing in the thermal process. In the present invention, considering the possibility that the dispersant itself adversely affects the use of the nanoparticles due to its effect, in principle, the dispersant is not used in the slurrying process in the present invention, or the physical properties of the nanoparticles are adversely affected. The amount can be reduced more than usual within a range that does not appear (for example, in the case of Ni nanoparticles for MLCC, the dispersant remaining after drying is 2 wt% or less).

<Freezing process>
This freezing step is a step of freezing the slurry produced in the above-described slurrying step, and corresponds to a part of the freeze-drying step. Any known cooling and freezing method can be used as long as it can cool to the melting point or lower of the organic solvent to be used.

  Specifically, it can be performed by a method of installing a processing container on a cooling shelf, which is performed by ordinary freeze-drying. However, in order to increase the freezing rate, it is desirable that the treatment shelf is precooled, and the precooling temperature is more desirably lower than the melting point of the organic solvent to be used. Moreover, it is preferable that not only the cooling shelf but also the processing container is pre-cooled, and the pre-cooling temperature is more preferably lower than the melting point of the organic solvent to be used.

  Furthermore, not only freezing by contact cooling with a cooling shelf or a processing vessel, but also cooling by a liquefied gas such as a cooled gas, liquid nitrogen, or liquefied carbon dioxide gas may be used in combination. In addition to these, as long as the conditions determined by cost, material, and application are satisfied, a freezing method by directly adding slurry into liquefied gas or the like may be used. In selecting the method, it is preferable to select a method that shortens the time required for freezing.

<Drying process>
This drying process corresponds to a part of the freeze-drying process. In this step, a vacuum drying method can be used in which the slurry temperature is controlled so as not to exceed the melting point of the organic solvent used. However, if cooling is performed more than necessary during the drying process, there is a problem that the time required for drying becomes longer. Therefore, it is preferable to control the slurry temperature as high as possible within a range not exceeding the melting point. In the drying step, since the heat of evaporation is taken away with the evaporation of the organic solvent, the slurry temperature usually decreases. Therefore, it is desirable to perform the heating while taking care that the sample temperature does not exceed the melting point.

  In addition, although it is necessary to provide sufficient time for drying, changes in slurry temperature during drying, input energy (heat amount) necessary for preventing overcooling, and the like are reference indicators due to the presence of the heat of evaporation. .

<Removal process>
After the drying step is completed, the pressure in the treatment tank is returned to normal pressure, and a removal step of taking out the dried nanoparticle that remains after slurry drying is performed. However, in order to prevent dew condensation on the nanoparticle dry body, it is desirable not to take out the nanoparticle dry body in a cooled state but to return the temperature of the nanoparticle dry body to room temperature. Note that as the gas used for returning the pressure to the normal pressure, other gases such as nitrogen and a rare gas can be used as appropriate in addition to the atmosphere, depending on the material and application.

Examples of the present invention and comparative examples will be described below.
<Example 1: Lyophilization of Ni nanoparticles (t-butanol)>
Under a nitrogen flow, 20.0 g of nickel acetate tetrahydrate and 226.0 g of oleylamine were mixed and then heated at 120 ° C. for 20 minutes with stirring to obtain a blue reaction solution 1. Next, the reaction solution 1 was irradiated with microwaves and heated at 250 ° C. for 5 minutes to obtain a nickel (Ni) nanoparticle slurry 1.

  The obtained Ni nanoparticle slurry 1 was allowed to stand and separated, and the supernatant liquid was removed, followed by washing three times with a mixed solvent having a volume ratio of methanol and toluene of 1: 4, and further using isopropyl alcohol (IPA) as a solvent. Substitution was performed and slurry 2 was obtained.

  The obtained slurry 2 was subjected to mechanical dispersion treatment to obtain slurry 3. FIG. 1 shows the particle size distribution of the slurry 3 obtained by the light scattering method. As shown in the figure, the slurry 3 showed a good dispersion state.

  Slurry 3 was prepared as slurry 4 using t-butanol as a solvent by solvent substitution, then poured into a pre-cooled metal vat, and quickly cooled to −40 ° C. in a lyophilizer to solidify. After the slurry was solidified, evacuation was started and lyophilization was performed. During freeze-drying, temperature was controlled by applying heat while controlling the slurry temperature to be equal to or lower than the melting point of the solvent used in order to efficiently dry and compensate for the heat of evaporation.

  After confirming that the solvent was removed from the amount of heat necessary for temperature control, the elapsed time, the state of the slurry, etc., cooling was stopped in a state where vacuuming was maintained, and the temperature was gradually raised to near room temperature. This is to prevent condensation due to atmospheric exposure in the cooled state. When the temperature reached around room temperature, it was opened to the atmosphere to obtain freeze-dried powder 1.

  The obtained freeze-dried powder 1 was again charged into IPA to obtain slurry 5. In addition, in the process of obtaining the slurry 5, the mechanical dispersion treatment as in the case of obtaining the slurry 3 is not performed. FIG. 2 shows the particle size distribution of the slurry 5 by the light scattering method. As shown in the figure, it was understood that although the slurry 5 was once dried, it was in a good dispersed state as much as before drying.

  Moreover, the coating film 1 which apply | coated the slurry 5 on smooth glass and dried was obtained. The coating film 1 has a metallic luster, suggesting that it has a smooth surface. When the surface roughness of the coating film 1 was measured with a laser microscope, Ra = 0.06 μm, which was confirmed to be extremely smooth (see FIG. 6B).

  Therefore, it was confirmed that the freeze-dried powder 1 has good redispersibility comparable to the state before drying.

<Example 2: Lyophilization of Ni nanoparticles (cyclohexane)>
A lyophilized powder 2 was obtained in the same manner as in Example 1 except that cyclohexane was used as the solvent used for lyophilization. FIG. 3 shows the particle size distribution of the slurry 6 obtained by treating the slurry 6 by the same treatment as that of the slurry 5 by the light scattering method. As shown in the figure, it can be seen that the dispersion is as good as before drying.

  In addition, when the surface roughness of the coating film obtained by applying the slurry 6 to a paste using a general matrix such as terpineol and applying and drying the surface roughness was measured, it was found that an extremely smooth surface of Ra = 0.0003 μm was obtained. (See FIG. 7 (a)).

<Example 3: Freeze drying of Ni nanoparticles (nitrobenzene)>
The same treatment as in Example 2 was performed to obtain freeze-dried powder 2. FIG. 4 shows the particle size distribution of the slurry 7 obtained by the same treatment as that of the slurry 5 except that nitrobenzene is used as a dispersion solvent. As shown in the figure, it is understood that when lyophilization is performed using an organic solvent, re-dispersion is hardly affected by the dispersion conditions (dispersion solvent).

<Comparative Example 1: Ni nanoparticles at room temperature>
The slurry 3 obtained in Example 1 was air-dried in an air atmosphere to obtain a normal (normal temperature) dry powder 1. The obtained dry powder 1 was put into IPA to obtain slurry A. In the process of obtaining the slurry A, the mechanical dispersion treatment as in the case of obtaining the slurry 3 is not performed. Slurry A has extremely poor dispersibility due to very strong agglomeration at the time of drying, and there are a large number of coarse particle masses that can be confirmed visually, and the particle size distribution should be measured in the same treatment as lyophilized powder. I couldn't even do it.

  Moreover, the coating film A which apply | coated the supernatant of the slurry A considered that there is comparatively little aggregation on smooth glass, and was dried was obtained. The coating film A does not have a metallic luster like the coating film 1 despite the use of a supernatant with relatively little aggregation, and is black, so it has a rough surface with poor smoothness. It is suggested. When the surface roughness of the coating film A was measured with a laser microscope, Ra = 1.14 μm, which was confirmed to be extremely rough as compared to the coating film 1 (see FIG. 6A). .

  Therefore, it was confirmed that a dry powder having high specific redispersibility can be obtained by using lyophilization.

<Comparative Example 2: Lyophilization of Ni nanoparticles with water solvent>
In Example 1, a lyophilized powder 3 was obtained by performing the same treatment except that water was used as the solvent used for lyophilization. About this freeze-dried powder 3, the particle size distribution by the light-scattering method of the slurry B obtained by the same process as the slurry 5 is shown in FIG. Since two peaks occur and each peak is not sharp, it can be seen that sufficient redispersion cannot be achieved when lyophilization is performed using water as a solvent.

  Further, when the surface roughness of the coating film obtained by applying the slurry B as a paste using a general matrix such as terpineol and applying and drying was measured, Ra = 0.022 μm, compared to the case of using an organic solvent for lyophilization. It was found that the surface had a low smoothness (see FIG. 7B). This result also shows that sufficient redispersion is not possible when lyophilization is performed using water as a solvent.

  Table 1 shows the results of surface composition analysis of freeze-dried 3 by X-ray photoelectron spectroscopy (XPS). In the table, the result of freeze-dried powder 3 is also shown. From the comparison between the two companies, a significant increase in the amount of oxygen is observed when water is used. That is, it can be seen that when water or the like is used in the case of a material having a high surface activity such as metal, modification such as oxidation occurs. Since the surface composition and chemical state greatly affect not only the dispersibility but also the characteristics of the material itself, it can be seen that it is desirable to use an organic solvent such as cyclohexane instead of using highly active water as a solvent.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  According to the present invention, it is possible to dry while removing the solvent in a state where the dispersion structure (state) is fixed by freezing, so that aggregation of particles in the drying process can be suppressed. Therefore, the nanoparticle dry body which has good handleability and can be applied to various fields is provided.

The present invention includes a step of producing a dispersion in which nanoparticles are dispersed in an organic solvent, a freeze-drying step of lyophilizing the dispersion to remove the organic solvent, and drying of the nanoparticles remaining after the freeze-drying step There is provided a method for producing a coated product , comprising a step of taking out a body, and a step of obtaining a slurry of the taken-out dried nanoparticle .

The present invention also includes a coating method in which a coating film produced by the above-described coating material manufacturing method is coated on a smooth surface to form a coating film .

Claims (7)

  A method for producing a dried nanoparticle comprising: a step of producing a dispersion in which nanoparticles are dispersed in an organic solvent; and a freeze-drying step of lyophilizing the dispersion to remove the organic solvent.   The manufacturing method of the nanoparticle dry body of Claim 1 whose melting | fusing point of the said organic solvent is -30 degreeC-30 degreeC.   The organic solvent is t-butanol, cyclohexane, acetic acid, acetophenone, acetylacetone, 2-aminoethanol, aniline, benzaldehyde, benzyl alcohol, benzylbenzoate, cyclohexanol, diethylene glycol, diethylene glycol monoethyl ether acetate, dimethylacetamide, dimethylsulfoxide, 1 , 4-dioxane, ethylene glycol, formamide, formic acid, glycerol, 2-methyl-2-butanol, nitrobenzene, 1-octanol, 3-pentanol, tetrachloroethylene, trifluoroacetic acid, xylene, or two The manufacturing method of the nanoparticle dry body of Claim 1 or 2 which is a mixture which combined the type or more.   The manufacturing method of the nanoparticle dry body of any one of Claim 1 to 3 in which the said organic solvent does not contain water.   The manufacturing method of the nanoparticle dry body of any one of Claim 1 to 4 whose said nanoparticle is a metal.   The method for producing a dried nanoparticle according to claim 5, wherein the metal is at least one of nickel, cobalt, silver, gold, platinum, copper, and aluminum.   The nanoparticle dry body manufactured by the manufacturing method of the nanoparticle dry body of any one of Claim 1 to 6.

Images