JP6567356B2 - Hollow carbon particles comprising elemental nitrogen and method for producing hollow carbon particles - Google Patents

Description

  The present invention relates to a hollow carbon particle containing nitrogen element and a method for producing the hollow carbon particle.

  Carbon materials are widely used in various applications because they are thermally and chemically stable and have electrical conductivity. In recent years, attempts have been made to hollow out particulate materials because various surface materials can have a large surface area while reducing the particle diameter.

  As a method for producing hollow particles using a phenol resin, polystyrene latex particles are dispersed in a phenol resin aqueous solution, and the dispersion is spray-pyrolyzed to produce hollow particles (for example, see Non-Patent Document 1). And a method using silica as a template (nucleating agent) (for example, see Non-Patent Document 2) is known.

  However, since the method described in Non-Patent Document 1 is produced by spray pyrolysis, there is a problem that the amount of spray and heat conduction are limited, and the productivity is extremely low. In the method described in Non-Patent Document 2, it is necessary to use toxic hydrogen fluoride in order to remove silica as a template, and a special container must be used. There was a problem. Furthermore, hollow carbon particles containing nitrogen elements are not known in the prior art.

Ratna Balgis et al., "Morphology control of hierarchical porous carbon particles from phenolic resin and polystyrene latex template via aerosol process", Carbon, 2015, volume 84, pages 281-289 Xianglin Yu et al., "Aerosol assisted synthesis of silica / phenolic resin composite mesoporous hollow spheres", Colloid Polymer Science, 2008, volume 286, pages 1361-1368

  An object of the present invention is to provide a hollow carbon particle containing elemental nitrogen and an efficient and safe method for producing a hollow carbon particle.

  In order to solve the above-mentioned problems, the present inventors have studied in detail the hollow carbon particles containing nitrogen element and the method for producing the hollow carbon particles. As a result, the present invention has been completed.

That is, the present invention includes the following preferred embodiments.
[1] Hollow carbon particles having one void inside and containing nitrogen element.
[2] The hollow carbon particles according to [1], wherein the content of nitrogen element is 1% by mass or more and 30% by mass or less with respect to the mass of the hollow carbon particles.
[3] The hollow according to [1] or [2], wherein the hollow carbon particles have an average particle diameter of 50 nm or more and 500 nm or less, and an average thickness of a carbon wall forming the hollow carbon particles is 1 nm or more and 200 nm or less. Carbon particles.
[4] A coating step of coating the surface of the core made of the resin composition having a negative zeta potential with a thermosetting resin to obtain a coated core,
A curing step of heating the coated core to cure the thermosetting resin to obtain a cured coated core;
A method for producing hollow carbon particles, comprising: a heat treatment step of thermally treating the cured coated core to thermally decompose the core to obtain a hollow carbon particle precursor; and a carbonization step of carbonizing the hollow carbon particle precursor.
[5] The production method according to the above [4], wherein the resin composition having a negative zeta potential comprises polystyrene.
[6] The production method according to [4] or [5], wherein the thermosetting resin comprises a phenol resin.
[7] The production method according to [6], wherein the phenol resin comprises a phenol resin having a nitrogen functional group.
[8] The production method according to any one of [4] to [7], wherein the curing step is performed in a liquid phase.
[9] The production method according to any one of [4] to [8], wherein the heat treatment step and the carbonization step are performed simultaneously.
[10] The production method according to any one of [4] to [9], wherein the heat treatment step and / or the carbonization step is performed in an inert gas atmosphere at a temperature of 300 ° C. or higher and 3000 ° C. or lower.

  According to the present invention, there are provided a hollow carbon particle having an advantage of a high specific surface area and a low density and containing nitrogen element, and an efficient and safe method for producing a hollow carbon particle.

1 is an electron microscopic observation view of a core manufactured according to Example 1. FIG. 1 is an electron microscopic observation view of hollow carbon particles produced according to Example 1. FIG. 1 is a transmission microscope observation view of hollow carbon particles produced according to Example 1. FIG. 3 is an electron microscopic observation view of hollow carbon particles produced according to Example 2. FIG. 3 is a transmission microscope observation view of hollow carbon particles produced according to Example 2. FIG. 4 is an electron microscopic observation view of hollow carbon particles produced according to Example 3. FIG. 4 is a transmission microscope observation view of hollow carbon particles produced according to Example 3. FIG. 6 is an electron microscopic observation view of a core manufactured according to Comparative Example 1. FIG. 2 is an electron microscopic observation view of a product manufactured according to Comparative Example 1. FIG. 6 is an electron microscopic observation view of a product manufactured according to Comparative Example 2. FIG.

  The hollow carbon particle of the present invention has one void inside and contains nitrogen element.

<Content of nitrogen element>
The amount of elemental nitrogen contained in the hollow carbon particles of the present invention depends on the thermosetting resin and heat treatment conditions used when producing the hollow carbon particles, and is preferably 1 mass relative to the mass of the hollow carbon particles. % To 30% by mass, more preferably 2% to 20% by mass, and particularly preferably 2% to 15% by mass. When the amount of the nitrogen element contained in the hollow carbon particles is within the above range, the nitrogen element-containing effect (for example, electrical effect) can be suitably obtained, and good stability against oxygen can be obtained. In the present invention, the content of nitrogen element can be measured using an oxygen / nitrogen / hydrogen analyzer (EMGA-930 manufactured by Horiba, Ltd.).

<Average particle size>
The average particle size of the hollow carbon particles of the present invention is preferably 50 nm or more and 500 nm or less, more preferably 60 nm or more and 400 nm or less. When the average particle diameter of the hollow carbon particles is within the above range, the hollow carbon particles can have good mechanical strength, can maintain the hollow, and the hollow region is preferably used to increase the surface area. Can bring.

<Average thickness of carbon wall>
The average thickness of the carbon walls forming the hollow carbon particles can be controlled by the amount of the thermosetting resin relative to the core, and is preferably 1 nm to 200 nm, more preferably 10 nm to 100 nm. When the average thickness of the carbon wall is within the above range, the preferred mechanical strength of the hollow carbon particles can be obtained and the hollowness can be maintained, and the thermosetting resin is not used excessively, thereby preventing adhesion between particles. You can also In the present invention, the average thickness of the carbon wall is obtained by observing hollow carbon particles with a transmission electron microscope (JEM3200-FS, manufactured by JEOL Ltd.), measuring the thickness of the carbon wall of 10 hollow carbon particles, and calculating the average value. Can be obtained by calculating.

<Gap>
The average diameter of the voids of the hollow carbon particles of the present invention can be adjusted by the average diameter of the core made of a resin composition having a negative zeta potential, which will be described later, preferably 50 nm or more and 200 nm or less, more preferably 60 nm. It is 180 nm or less. When the average diameter of the voids of the hollow carbon particles is within the above range, the voids inside the hollow carbon particles (hereinafter sometimes referred to as hollow regions) are suitably used, and a favorable increase in surface area can be brought about. In the present invention, the average diameter of the voids is obtained by observing the hollow carbon particles with a transmission electron microscope (JEM3200-FS, manufactured by JEOL Ltd.), measuring the diameter of the voids of 10 hollow carbon particles, and calculating the average value. Can be obtained.

  The porosity of the hollow carbon particles of the present invention is preferably 1% or more and 90% or less, more preferably 5% or more and 90% or less, and further preferably 10% or more and 85% or less with respect to the volume of the hollow carbon particles. . When the porosity of the hollow carbon particles is within the above range, the hollow region can be suitably used, and good mechanical strength can be obtained.

  The shape of the void is not particularly limited. It is preferable from the viewpoint that the mechanical strength is maintained and the uneven distribution hardly occurs when the third component is injected into the hollow region, when the shape of the void is spherical.

  The hollow carbon particles of the present invention usually have one void inside, but may have two or more voids.

The method for producing hollow carbon particles is:
A coating step of coating the surface of a core made of a resin composition having a negative zeta potential with a thermosetting resin to obtain a coated core;
A curing step of heating the coated core to cure the thermosetting resin to obtain a cured coated core;
It includes a heat treatment step in which the cured coated core is heat treated to thermally decompose the core to obtain a hollow carbon particle precursor, and a carbonization step in which the hollow carbon particle precursor is carbonized.

<Core>
In the present invention, the core is made of a resin composition having a negative zeta potential. The resin composition having a negative zeta potential is preferably formed by polymerization of an aromatic vinyl monomer such as styrene, a vinyl monomer such as vinyl acetate, or a (meth) acrylic acid monomer such as methyl methacrylate. A resin capable of being produced. The resin composition having a negative zeta potential includes a resin produced using styrene from the viewpoints of being easily thermally decomposable and not generating an activation gas such as water and carbon dioxide during decomposition. More specifically, it is more preferable that the resin composition having a negative zeta potential comprises polystyrene. The resin composition having a negative zeta potential may further contain an additive such as an emulsifier such as dodecylbenzenesulfonic acid as long as the performance as a core is not impaired. The content of the additive is preferably 5% by mass or less, more preferably 1% by mass or less, based on the resin composition having a negative zeta potential.

  The core is made of a resin composition having a negative zeta potential. “Zeta potential” is the difference between the potential of the core surface and the potential of a solution sufficiently away from it, and “the core is made of a resin composition having a negative zeta potential” means that the core is negative. It is that it is charged. The zeta potential of the core is not particularly limited as long as it is negative. Preferably they are -30v or more and -70mV or less, More preferably, they are -40mV or more and -60mV or less.

  Depending on the surface potential of the core, when the surface of the core is coated with the thermosetting resin, the manner in which the thermosetting resin is fixed to the core changes. Specifically, the fixing is homogenized or the coated cores are fused together. When the coated cores are bonded to each other, the thermosetting resin coating layer is locally thinned after the curing step, so that it cannot withstand the carbonization treatment described later, and hollow carbon particles cannot be formed.

  The average diameter of the core used in the present invention is not particularly limited because it depends on the desired average diameter of the voids of the hollow carbon particles. The average diameter of the core is preferably 50 nm to 200 nm, more preferably 60 nm to 180 nm. When the average diameter of the core is within the above range, a suitable hollow region can be obtained, and a favorable increase in surface area can be obtained, and the hollow region can be maintained without being blocked by the carbonization treatment described later. .

  The manufacturing method of the core in this invention is not specifically limited. The core can be produced, for example, by adding a monomer to distilled water, purified water or ion-exchanged water as a solvent, sufficiently stirring, suspending, adding a polymerization initiator, and stirring with heating.

  The monomer is not particularly limited as long as a negatively charged core can be produced. One or more monomers such as aromatic vinyl monomers such as styrene, vinyl monomers such as vinyl acetate, and (meth) acrylic acid monomers such as methyl methacrylate can be used. It is preferable to use a styrenic monomer from the viewpoint that it can be thermally decomposed easily and does not generate an activating gas such as water or carbon dioxide during decomposition. It is more preferable to use styrene having a structural unit derived from a hydrophobic monomer such as styrene or alkyl (meth) acrylate, and styrene having another copolymerizable monomer structural unit, for example, having 3 to 22 carbon atoms. Alkyl (meth) acrylate styrene having an alkyl group, and 2-methylstyrene can be used.

  The concentration of the monomer in the solvent is not particularly limited. The amount is preferably 0.01 mol or more and 1 mol or less, and more preferably 0.02 mol or more and 0.8 mol or less per liter of the solvent. When the concentration of the monomer in the solvent is within the above range, the coarsening of the core due to aggregation can be avoided, and the stability of the emulsion can be ensured.

  The zeta potential of the core can be adjusted by the polymerization initiator. When producing a core using a styrene monomer, an inorganic peroxide can be used as a polymerization initiator in order to make the zeta potential of the core negative. The inorganic peroxide is not particularly limited, and for example, ammonium persulfate, lithium persulfate, sodium persulfate, potassium persulfate, calcium persulfate, magnesium persulfate, and the like can be used. In order to avoid the residue of the polymerization initiator in the produced core, it is preferable to use ammonium persulfate, sodium persulfate, or ammonium persulfate. When a core is produced using a vinyl monomer and a (meth) acrylic acid monomer, a water-soluble anionic polymerization initiator such as potassium persulfate and 2,2′-azobis (2-methyl) are used as a polymerization initiator. Water-soluble cationic polymerization initiators such as propionamidine) dihydrochloride can be used. It is preferable to use a water-soluble cationic polymerization initiator.

The concentration of the polymerization initiator is not particularly limited as long as the polymerization proceeds. It is preferably 0.1 × 10 ⁻⁴ mol or more and 2 × 10 ⁻⁴ mol or less, and more preferably 0.2 × 10 ⁻⁴ mol or more and 1 × 10 ⁻⁴ mol or less per liter of the solvent. When the concentration of the polymerization initiator is within the above range, a suitable polymer molecular weight can be obtained, so that the shape of the core can be maintained and the polymerization can be sufficiently advanced.

  There is no particular limitation on the temperature at which the polymerization of the monomer is carried out. The temperature may be any temperature at which polymerization proceeds, and is usually from 40 ° C. to 90 ° C., preferably from 50 ° C. to 80 ° C. When the temperature at which the monomer polymerization is performed is within the above range, the polymerization can be sufficiently progressed so that monomer residue can be avoided, and the average diameter of the core is controlled because the polymerization rate is not too high. can do.

  The reaction time of the polymerization of the monomer depends on the polymerization temperature and cannot be particularly specified. Usually, it is 1 hour or more and 100 hours or less, preferably 2 hours or more and 80 hours or less.

  A core having a desired average diameter and zeta potential can be manufactured by the manufacturing method described above.

<Coating process>
In the coating step, the core of the resin composition having a negative zeta potential can be coated with a thermosetting resin to obtain a coated core.

  In the present invention, the thermosetting resin is preferably one phenol resin, polycarbodiimide resin, epoxy resin, furan resin, polyimide resin, polyamide resin, polyamideimide resin, melamine resin, polyacrylonitrile resin, unsaturated polyester resin. Including the above. From the viewpoint of the carbonization yield and the nitrogen element content of the carbide, more preferably, the thermosetting resin comprises a phenol resin.

  The phenol resin can be produced by a condensation (polymerization) reaction between phenols and formaldehyde. The phenols that can be used are not particularly limited as long as they form a phenol resin by polymerization with formaldehyde. For example, phenol, cresol, xylenol, bisphenol A, bisphenol F, resorcinol, methyl resorcinol, aminophenol and the like can be used. In this invention, since it is preferable that a phenol resin contains the phenol resin which has a nitrogen functional group, it is preferable that phenols are a phenol which has a nitrogen functional group. The phenol having a nitrogen functional group is, for example, 2-aminophenol, 3-aminophenol, 4-aminophenol, 2,6-diaminophenol, or 2,4-diaminophenol. In view of availability and economy, 2-aminophenol and 4-aminophenol are particularly preferable.

  The mixing ratio of phenols and formaldehyde is not particularly limited as long as a large amount of formaldehyde is mixed in order to completely react and consume the phenol content. Formaldehyde is usually used at a mixing ratio of 1.0 to 10 mol times, preferably 1.0 to 8 mol times with respect to 1 mol of phenols. When the mixing ratio is within the above range, the phenol content can be completely consumed by the reaction, and insoluble paraformaldehyde can be prevented from being generated by the self-condensation of too much formaldehyde.

  In the present invention, the composition ratio between the thermosetting resin and the core is not particularly limited. The thermosetting resin is usually used in an amount of 0.01 g to 50 g, preferably 0.05 g to 20 g, relative to 1 g of the core. When the composition ratio between the thermosetting resin and the core is within the above range, the core can be satisfactorily coated, and it is possible to avoid the formation of a product composed only of the thermosetting resin before coating.

  The temperature at which the polymerization reaction of the thermosetting resin is performed is not particularly limited. Usually, it can be carried out at a temperature of 40 to 200 ° C., preferably 60 to 180 ° C., more preferably 120 to 180 ° C. If the temperature for carrying out the polymerization reaction of the thermosetting resin is within the above range, the polymerization reaction proceeds within an appropriate time, so that an economic advantage can be secured, and before the polymerization reaction proceeds on the core surface. It is possible to avoid polymerization of the thermosetting resin.

  The heating method is not particularly limited. An autoclave can be used for pressurization and heating, and heating can be performed by irradiating microwaves to accelerate the polymerization reaction.

  When the core is produced in a solvent as described above, the core can be obtained in a state dispersed in the solvent. In the present invention, a core (coated core) coated with a thermosetting resin (for example, phenol resin) can be obtained by adding a thermosetting resin component (for example, phenols and formaldehyde) to the dispersion. The coated core can be separated from the dispersed state by filtration or centrifugation.

<Curing process>
In the curing step, the coated core can be heated to cure the thermosetting resin, and a cured coated core can be obtained. The temperature at which the curing reaction is carried out depends on the thermosetting resin used. Usually, it can be carried out at a temperature of 40 to 200 ° C., preferably 60 to 180 ° C., more preferably 120 to 180 ° C.

  The coating step and the curing step can be performed simultaneously, and by performing simultaneously, adhesion between the coated cores and the cured coated cores can be further suppressed. The temperature at which the coating step and the curing step are performed simultaneously is usually 40 ° C. or higher and 200 ° C. or lower, preferably 60 ° C. or higher and 180 ° C. or lower, more preferably 120 ° C. or higher and 180 ° C. or lower. When the temperature at which the coating step and the curing step are simultaneously performed is within the above range, the thermosetting resin is polymerized on the core surface, and the curing of the thermosetting resin can sufficiently proceed.

  The method for heating is not particularly limited. An autoclave can be used as a method of pressurization and heating, and in order to promote the reaction, it can be heated by irradiation with microwaves.

  When the core is produced in a solvent as described above, the core can be obtained in a state dispersed in the solvent. In the present invention, as described above, a coated core can be obtained by adding a thermosetting resin component to this dispersion (coating step). After the coating step or simultaneously with the coating step, the curing step is performed. It can be carried out. In such a case, the curing step is performed in a liquid phase, which is preferable from the viewpoint of avoiding adhesion between the coated cores and the cured coated cores. The cured coated core can be separated by filtration or centrifugation.

  The separated cured coated core can also be dried, and the method is not particularly limited. It can be dried under atmospheric pressure or reduced pressure. It can also heat at the time of drying, Usually, it can heat at 40 to 200 degreeC, Preferably it can heat at 60 to 180 degreeC. When the heating temperature at the time of drying the cured coated core is within the above range, the cured coated core can be dried within an appropriate time without melting the core.

<Heat treatment process>
In the heat treatment step, the hardened coated core is heat treated to thermally decompose the core, thereby obtaining a hollow carbon particle precursor. The heat treatment temperature is not particularly limited as long as the core is decomposed and volatilized. Usually, it is 300 to 3000 ° C, preferably 350 to 2800 ° C, more preferably 400 to 2500 ° C. When the heat treatment temperature is within the above range, the core can be decomposed and volatilized without any residue, and a hollow region can be provided.

  The heat treatment time is not particularly limited. Usually, it is 1 minute to 300 minutes, preferably 5 minutes to 270 minutes, more preferably 10 minutes to 240 minutes. When the heat treatment time is within the above range, the core can be decomposed and volatilized well, and a hollow region can be provided.

  The rate of temperature increase when heat-treating the cured coated core is not particularly limited. Usually, it is 0.1 ° C. or more and 200 ° C. or less per minute, preferably 0.5 ° C. or more and 180 ° C. or less per minute. If the temperature rising rate when heat-treating the cured coated core is within the above range, the structure of the hollow carbon particle precursor can be maintained because the thermal decomposition rate of the core is not too high, Since carbonization does not occur, a decrease in carbon purity can be avoided.

  The heat treatment can also be performed in an inert gas atmosphere. Nitrogen, argon, etc. can be used as the inert gas. In view of economy and availability, it is preferable to use nitrogen.

<Carbonization process>
In the carbonization step, the hollow carbon particle precursor can be carbonized to obtain hollow carbon particles. The carbonization temperature is not particularly limited as long as it is a temperature at which the hollow carbon particle precursor can be carbonized. Usually, it is 300 to 3000 ° C, preferably 350 to 2800 ° C, more preferably 400 to 2500 ° C. When the carbonization temperature is within the above range, the carbonization treatment can be sufficiently performed, and when the phenol resin contains a phenol resin having a nitrogen functional group, a decrease in nitrogen content derived from the nitrogen functional group can be avoided. .

  The carbonization time is not particularly limited. Usually, it is 1 minute to 300 minutes, preferably 5 minutes to 270 minutes, more preferably 10 minutes to 240 minutes. When the carbonization time is within the above range, the carbonization treatment can be sufficiently performed, and when the phenol resin contains a phenol resin having a nitrogen functional group, an excessive decrease in nitrogen content derived from the nitrogen functional group is avoided. Can do.

  The rate of temperature increase during the carbonization treatment is not particularly limited. Usually, it is 0.1 ° C. or more and 200 ° C. or less per minute, preferably 0.5 ° C. or more and 180 ° C. or less per minute. If the rate of temperature increase during the carbonization treatment is within the above range, the structure of the hollow carbon particles is maintained because of the carbonization rate that is not too fast, so that a reduction in carbonization yield can be avoided.

  The carbonization treatment is preferably performed in an inert gas atmosphere. Nitrogen, argon, etc. can be used as the inert gas. In consideration of economy and availability, it is preferable to carry out under nitrogen. By carbonizing the hollow carbon particle precursor in an inert gas atmosphere, it is possible to suppress a decrease in yield due to combustion, oxidation, and thermal decomposition promotion of the phenol resin.

  Preferably, the heat treatment step and the carbonization step are performed simultaneously. Thereby, since time and energy can be saved, production efficiency can be improved. When performed simultaneously, the heat treatment and carbonization are usually performed at a temperature of 300 ° C. or higher and 3000 ° C. or lower, preferably 350 ° C. or higher and 2800 ° C. or lower, more preferably 400 ° C. or higher and 2500 ° C. or lower. It is preferable to carry out in inert gas atmosphere from a viewpoint of suppressing this.

  The hollow carbon particles obtained by carbonizing the hollow carbon particle precursor can be recovered after cooling. The recovered hollow carbon particles can be stored under nitrogen as necessary, thereby suppressing the oxidation of the carbon content and maintaining the physical properties immediately after the carbonization treatment.

<Content of nitrogen element>
When the phenol resin comprises a phenol resin having a nitrogen functional group, the amount of nitrogen element contained in the hollow carbon particles obtained by the production method of the present invention is preferably 1 mass relative to the mass of the hollow carbon particles. % To 30% by mass, more preferably 2% to 20% by mass, and preferably 2% to 15% by mass from the viewpoint of exhibiting conductivity. The content of this nitrogen element depends on the content of nitrogen in the molecule of phenols having a nitrogen functional group, and the type and position of the nitrogen functional group. Furthermore, it depends on the amount of formaldehyde used (mixing ratio with phenols having a nitrogen functional group). When the amount of the nitrogen element contained in the hollow carbon particles is within the above range, the nitrogen element-containing effect (for example, electrical effect) can be suitably obtained, and good stability against oxygen can be obtained. The content of elemental nitrogen can be measured by the procedure described above.

<Average particle size>
The average particle diameter of the hollow carbon particles obtained by the production method of the present invention is preferably 50 nm or more and 500 nm or less, more preferably 60 nm or more and 400 nm or less. When the average particle diameter of the hollow carbon particles is within the above range, the hollow carbon particles can have good mechanical strength, can maintain the hollow, and the hollow region is preferably used to increase the surface area. Can bring.

<Average thickness of carbon wall>
The average thickness of the carbon wall forming the hollow carbon particles obtained by the production method of the present invention can be controlled by the amount of the thermosetting resin relative to the core, preferably 1 nm to 200 nm, more preferably 10 nm to 100 nm. It is. When the average thickness of the carbon wall is within the above range, the preferred mechanical strength of the hollow carbon particles can be obtained and the hollowness can be maintained, and the thermosetting resin is not used excessively, thereby preventing adhesion between particles. You can also The average thickness of the carbon wall can be measured by the procedure described above.

<Gap>
The average diameter of the voids of the hollow carbon particles obtained by the production method of the present invention can be adjusted by the average diameter of the core, and is preferably 50 nm to 200 nm, more preferably 60 nm to 180 nm. When the average diameter of the voids of the hollow carbon particles is within the above range, the voids inside the hollow carbon particles can be suitably used to bring about a good surface area increase. The average diameter of the voids can be measured by the procedure described above.

  The porosity of the hollow carbon particles obtained by the production method of the present invention is preferably 1% or more and 90% or less, more preferably 5% or more and 90% or less, and still more preferably 10% or more with respect to the volume of the hollow carbon particles. 85% or less. When the porosity of the hollow carbon particles is within the above range, the hollow region can be suitably used, and good mechanical strength can be obtained.

  The shape of the voids of the hollow carbon particles obtained by the production method of the present invention is not particularly limited. It is preferable from the viewpoint that the mechanical strength is maintained and the uneven distribution hardly occurs when the third component is injected into the hollow region, when the shape of the void is spherical.

  The hollow carbon particles obtained by the production method of the present invention usually have one void inside, but may have two or more voids.

Examples Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the examples. The characteristics of the hollow carbon particles obtained in the respective examples and comparative examples were evaluated as follows.

Average diameter of the core:
Using the observation drawing of the core obtained by a transmission electron microscope (JEM3200-FS manufactured by JEOL Ltd.), the diameter of 10 cores was measured, and the average value was taken as the average diameter of the core.

Elemental nitrogen content:
The measurement was performed according to the procedure described above.

Average particle size of hollow carbon particles:
Using the observation drawing of hollow carbon particles obtained by a transmission electron microscope (JEM3200-FS manufactured by JEOL Ltd.), the particle diameter of 10 hollow carbon particles was measured, and the average value was calculated as the average particle diameter of the hollow carbon particles. did.

Average thickness of carbon wall:
The measurement was performed according to the procedure described above.

Average diameter of voids:
The measurement was performed according to the procedure described above.

Porosity:
The porosity is given by the following formula:
Calculated from

Example 1
A stirrer, a reflux tube and a thermometer were connected to a 1 L three-necked flask, and 600 mL of ion-exchanged water was introduced. Thereto, 2 g of styrene and 0.03 g of potassium persulfate were added, and the system was heated to 70 ° C. while flowing nitrogen. The mixture was stirred at 70 ° C. for 24 hours while maintaining a rotation speed of 400 rpm. The reaction solution was cooled to room temperature, and the obtained dispersion was dropped on a cover glass and dried, and then observed using an electron microscope. The results are shown in FIG. In the electron microscopic observation drawing, the diameters of 10 cores were measured, and the average value thereof was 81.6 nm. When the zeta potential of the obtained core dispersion was measured using Zeta Sizer Nano ZSP (manufactured by Malvern), it was -50.4 mV.
To this core dispersion, 2 g of 3-aminophenol was added, and 2 mL of a 17% aqueous ammonia solution and 100 g of ethanol were added. While stirring the mixed solution, 1.88 g of a 30% formaldehyde solution (equal molar amount of 3-aminophenol) was added, and the mixture was reacted at 150 ° C. for 30 minutes while being irradiated with microwaves.
After cooling the reaction solution, the hardened coated core was separated using a centrifuge. The cured coated core was dried at 100 ° C. and 13 Pa for 4 hours, and then heat-treated and carbonized in a fast reactor (manufactured by Motoyama) at 550 ° C. for 2 hours under nitrogen. The mixture was cooled to room temperature to obtain 1.22 g of hollow carbon particles. The electron microscope observation figure of the obtained hollow carbon particle is shown in FIG. 2, and the transmission microscope observation figure is shown in FIG. Table 1 shows the results of elemental analysis.

Example 2
To the core dispersion obtained in Example 1, 10 g of 3-aminophenol was added, and 10 ml of a 17% aqueous ammonia solution and 100 g of ethanol were added. While stirring the mixed solution, 9.40 g of a 30% formaldehyde solution (3-aminophenol equimolar amount) was added, and the mixture was reacted at 150 ° C. for 30 minutes while being irradiated with microwaves.
After cooling the reaction solution, the hardened coated core was separated using a centrifuge. The cured coated core was dried at 100 ° C. and 13 Pa for 4 hours, and then heat-treated and carbonized in a fast reactor (manufactured by Motoyama) at 550 ° C. for 2 hours under nitrogen. The mixture was cooled to room temperature to obtain 6.18 g of hollow carbon particles. The electron microscope observation figure of the obtained hollow carbon particle is shown in FIG. 4, and the transmission microscope observation figure is shown in FIG. Table 1 shows the results of elemental analysis.

Example 3
A fast reactor (manufactured by Motoyama) was used in the same manner as in Example 2 except that it was heat-treated and carbonized at 800 ° C. for 2 hours under nitrogen to obtain 2.18 g of hollow carbon particles. The electron microscope observation figure of the obtained hollow carbon particle is shown in FIG. 6, and the transmission microscope observation figure is shown in FIG. The results of elemental analysis are shown in Table 1.

Comparative Example 1
A stirrer, a reflux tube and a thermometer were connected to a 1 L three-necked flask, and 600 ml of ion-exchanged water was introduced. Thereto, 2 g of styrene and 0.02 g of 2-amidinopropane hydrochloride were added, and the system was heated to 70 ° C. while flowing nitrogen. The mixture was stirred at 70 ° C. for 24 hours while maintaining a rotation speed of 400 rpm. The reaction solution was cooled to room temperature, and the obtained dispersion was dropped on a cover glass and dried, and then observed using an electron microscope. The results are shown in FIG. In the electron microscopic observation drawing, the diameters of 10 cores were measured, and the average value thereof was 81.4 nm. When the zeta potential of the obtained core dispersion was measured using Zeta Sizer Nano ZSP (manufactured by Malvern), it was +46.4 mV.
To this core dispersion, 10 g of 3-aminophenol was added, and 10 ml of a 17% aqueous ammonia solution and 100 g of ethanol were added. While stirring the mixed solution, 9.40 g of a 30% formaldehyde solution (3-aminophenol equimolar amount) was added, and the mixture was reacted at 150 ° C. for 30 minutes while being irradiated with microwaves.
After cooling the reaction solution, the product was collected using a centrifuge. The product was dried at 100 ° C. and 13 Pa for 4 hours, then heat-treated and carbonized at 550 ° C. for 2 hours in a fast reactor (manufactured by Motoyama) and cooled to room temperature. The electron microscope observation figure of a product is shown in FIG. It can be seen that the particles adhere to each other and do not exist as single particles. In addition, a clear hollow region could not be observed.

Comparative Example 2
In Comparative Example 1, the same procedure was performed as in Comparative Example 1 except that the product was heat-treated and carbonized at 800 ° C. for 2 hours in nitrogen in a fast reactor (manufactured by Motoyama). The electron microscope observation figure of a product is shown in FIG. It can be seen that the particles adhere to each other and do not exist as single particles.

  According to the present invention, it is possible to provide a hollow carbon particle containing nitrogen element and an efficient and safe method for producing a hollow carbon particle, which have advantages such as a high specific surface area and a low density. The hollow carbon particles of the present invention can be extremely usefully used for battery materials, catalyst carriers and the like.

Claims (8)

Hollow carbon particles having one void inside and containing nitrogen element , the hollow carbon particles are derived from a thermosetting resin containing a phenol resin, and the average particle diameter of the hollow carbon particles Is a hollow carbon particle in which the average thickness of the carbon wall forming the hollow carbon particle is 1 nm or more and 200 nm or less .   The hollow carbon particles according to claim 1, wherein the content of nitrogen element is 1% by mass or more and 30% by mass or less with respect to the mass of the hollow carbon particles. A coating step of coating the surface of the core made of a resin composition having a negative zeta potential with a thermosetting resin containing a phenol resin to obtain a coated core;
A curing step of heating the coated core to cure the thermosetting resin to obtain a cured coated core;
The hollow according to claim 1 , comprising a heat treatment step of heat-treating the cured coated core to thermally decompose the core to obtain a hollow carbon particle precursor, and a carbonization step of subjecting the hollow carbon particle precursor to carbonization. A method for producing carbon particles. The manufacturing method according to claim 3 , wherein the resin composition having a negative zeta potential comprises polystyrene. The production method according to claim 3 or 4 , wherein the phenol resin comprises a phenol resin having a nitrogen functional group. Perform the curing step in a liquid phase process according to any one of claims 3-5. Performing the aforementioned heat treatment step and the carbonization step at the same time, the production method according to any one of claims 3-6. The manufacturing method according to any one of claims 3 to 7 , wherein the heat treatment step and / or the carbonization step is performed in an inert gas atmosphere at a temperature of 300 ° C or higher and 3000 ° C or lower.