JP2010100514A - Ceramic particle and method of manufacturing the same - Google Patents

Abstract

Disclosed is a ceramic particle capable of increasing the reaction area with an eluent or the like without reducing the diameter of the particle itself, and a method for producing the same.
A ceramic particle according to the present invention is provided with a plurality of open pores 20 on an outer surface 10a, and the open pores 20 have an average pore diameter of 500 nm or more and 50 μm or less, and an opening of the outer surface 10a of the open pores 20 is provided. The diameter of the part is 300 nm or more and 20 μm or less.
[Selection] Figure 1

Description

  The present invention relates to ceramic particles and a method for producing the same.

  Ceramic particles are widely used for catalyst carriers, cell culture carriers, liquid chromatography fillers and the like because of their excellent adsorptivity to catalysts, cells, proteins and the like.

  Such ceramic particles are required to have a high specific surface area in order to enhance reactivity with other substances.

  In response to such requirements, for example, the pores have continuous pores with an average pore size of 100 to 4000 mm, and 70% or more of the total pore volume is pores having a pore size in the range of 0.5 to 2 times the average pore size. Porous, which is a spherical particle having an average particle diameter of 1 to 40 μm and comprising a calcium phosphate compound having a Ca / P ratio of 1.5 to 1.80 and having a pore volume per 1 g of particles of 0.05 ml or more Calcium phosphate compound particles are disclosed (for example, Patent Document 1).

  In addition, a technique for reducing the diameter of the particle itself in order to obtain a high specific surface area is also generally known.

Japanese Patent Publication No. 8-32551 (eg, [Claim 1])

  However, since the eluent or gas (hereinafter referred to as eluent) does not easily flow into the continuous pores having an average pore size as described in Patent Document 1, the portion having substantial reactivity is ceramics. There can be only the outer surface of the particles. Therefore, the reaction area with the eluent or the like cannot be increased, and there is a limit to improving the separation performance.

  In addition, in order to obtain a high specific surface area, the technology for reducing the diameter of the particles themselves is, for example, when the reduced-size particles are packed in a column, the flow resistance of the eluent sent to the column increases, and the pressure loss increases. However, there is a problem that the device load increases.

  The present invention has been made in view of such circumstances, and an object thereof is to provide ceramic particles capable of increasing the reaction area with an eluent or the like without reducing the diameter of the particles themselves, and a method for producing the same. .

The ceramic particles according to the present invention are ceramic particles having a plurality of open pores on the outer surface,
The open pores have an average pore diameter of 500 nm or more and 50 μm or less,
The diameter of the opening on the outer surface of the open pore is 300 nm or more and 20 μm or less,
The skeleton part constituting the open pores is constituted by a porous body.

  Since such a configuration is provided, the ceramic particles according to the present embodiment can increase the reaction area with the eluent or the like without reducing the diameter of the particles themselves.

The ceramic particles according to the present invention are ceramic particles having a plurality of open pores on the outer surface,
The open pores are surface open pores having an average pore diameter of 500 nm or more and 50 μm or less provided on the outer surface;
An internal pore having an average pore diameter of 500 nm or more and 50 μm or less provided in communication with the inner wall surface of the surface open pore;
The aperture of the outer surface of the surface open pores and the aperture of the communication portion between the surface open pores and the internal open pores are 300 nm or more and 20 μm or less,
The skeleton part constituting the open pores is constituted by a porous body.

  Since such an arrangement is provided, the eluent or the like flows into the ceramic particles, so that the reaction area with the eluent or the like can be further increased.

  The open pores are preferably provided so as to communicate from one outer surface of the ceramic particles to the other outer surface.

  Since such a configuration is provided, the eluent and the like can be poured uniformly into the ceramic particles, so that the reaction area with the eluent and the like can be maximized.

  The ceramic particles are made of any of inorganic oxides such as alumina, silica, mullite, zirconia, and calcium phosphate, silicon carbide, boron carbide, or silicon nitride.

  Because of such a configuration, the ceramic particles according to the present invention can be widely used for catalyst carriers, cell culture carriers, liquid chromatography fillers, and the like.

  In the method for producing ceramic particles according to the present invention, a first oil and a hydrophilic surfactant are added to a slurry (W) containing ceramic powder, a binder, a dispersant, and pure water, By applying a shear stress to the oil, oil droplet particles (O) composed of the first oil are formed, and the oil droplet particles (O) are dispersed in the slurry (W). The step of preparing an emulsion, and adding the O / W emulsion to a second oil (O) containing a lipophilic surfactant and applying a shear stress to the O / W emulsion, the oil droplet particles O / W in which fine droplets (O / W) composed of a slurry in which (O) is confined are formed, and the fine droplets (O / W) are dispersed in the second oil (O). A process for producing a W / O emulsion and firing the fine droplets (O / W) And that step, characterized in that it comprises a.

  The ceramic particles according to the present invention described above can be manufactured by such a manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the ceramic particle which can enlarge reaction area with an eluent etc., and its manufacturing method are provided, without reducing particle | grain itself.

The conceptual diagram of the external appearance of the ceramic particle concerning this embodiment. The conceptual diagram of the cross section from the surface of the ceramic particle concerning this embodiment to the inside. The process conceptual diagram for demonstrating the manufacturing method of the ceramic particle concerning this embodiment. The evaluation result of the separation characteristic in Example 1. FIG. The evaluation result of the separation characteristic in the comparative example 1. The evaluation result of the separation characteristic in the comparative example 2. The evaluation result of the separation characteristic in the comparative example 3. The SEM photograph of the ceramic particle before classifying to the average particle diameter produced in Example 1 to 80 micrometers.

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

  FIG. 1 shows a conceptual diagram of the appearance of ceramic particles according to this embodiment, and FIG. 2 shows a conceptual diagram of a cross section from the surface to the inside of the ceramic particles according to this embodiment.

  As shown in FIG. 1, the ceramic particle 10 according to the present embodiment includes a plurality of open pores 20 on the outer surface 10a.

As shown in FIG. 2, the open pores 20 are provided with surface open pores 20a having an average pore diameter of 500 nm or more and 50 μm or less provided on the outer surface 10a, and the diameter of the opening on the outer surface 10a side of the surface open pores 20a. O _t is composed of 300 nm or more and 20 μm or less.

  Since the eluent and the like flow into the surface open pores 20a of the ceramic particles 10 because of such a configuration, the ceramic particles according to the present embodiment can be separated from the eluent and the like without reducing the diameter of the particles themselves. The reaction area can be increased.

  In addition, when the average pore diameter is less than 500 nm, the diameter of the opening may be less than 300 nm, and it becomes difficult for the eluent to flow into the surface open pores. It is difficult to increase the area, and there is a limit to improving the separation performance. Further, when the average pore diameter exceeds 50 μm, the diameter of the opening may exceed 20 μm, and the strength of the ceramic particles 10 itself may be lowered, which is not preferable. In addition, since the reduction | decrease of the intensity | strength of ceramic particle | grains 10 induces destruction of the ceramic particle | grains 10 and causes this to reduce the diameter of ceramic particle | grains, the problem that a pressure loss increases as a result will generate | occur | produce.

As shown in FIG. 2, the open pores 20 communicate with at least the surface open pores 20a provided on the outer surface 10a having an average pore diameter of 500 nm or more and 50 μm or less, and the inner wall surface 20a1 of the surface open pores 20a. Provided with an internal open pore 20b having an average pore size of 500 nm or more and 50 μm or less, the diameter O _t of the opening on the outer surface 10a side of the surface open pore 20a and the surface open pore 20a and the internal open pore 20b. It is preferable that the diameter R _{t1 of the} communication portion between the first and second portions is 300 nm or more and 20 μm or less.

  Since such a configuration is provided, since the eluent and the like flow into the ceramic particles 10 (internal open pores 20b), the reaction area with the eluent and the like can be further increased.

Furthermore, it is preferable that the open pores 20 are provided so as to communicate from one outer surface of the ceramic particle 10 to the other outer surface. That is, as shown in FIG. 2, a plurality of surface open pores such as a second internal open pore 20c having an average pore diameter of 500 nm to 50 μm provided in communication with the inner wall surface 20b1 of the internal open pore 20b. 20a and internal open pores 20b, 20c... Are preferably provided so as to communicate from one outer surface of the ceramic particle 10 to the other outer surface. In this case, similarly, the diameter R _{t2 of the} communicating portion between the internal open pores 20b, 20c... Is preferably 300 nm or more and 20 μm or less.

  By providing such a configuration, it is possible to flow the eluent etc. evenly into the ceramic particles, so that the reaction area with the eluent etc. can be maximized.

  The surface open pores and the internal open pores here are formed by spherical pores. The skeleton part constituting the spherical open pores is formed of a non-spherical porous body. The spherical shape is not limited to a strictly spherical shape, and includes a shape in which the true sphere is slightly flattened or distorted. Non-spherical means something other than the above-mentioned spherical shape.

The average pore diameter is a value calculated by image diffraction after observing an electron microscope with ceramic particles embedded in a resin and polishing the surface. The apertures O _t , R _t1 , and R _t2 are values measured by a mercury intrusion method using a mercury porosimeter.

    The particle diameter of the ceramic particles 10 according to the present embodiment is not particularly limited as long as the plurality of open pores 20 are provided and the ceramic particles 10 have a size that can maintain the strength as the ceramic particles 10. The particle size of the ceramic particles 10 according to the present embodiment is, for example, 10 μm or more and 200 μm or less.

    The ceramic particles 10 according to this embodiment described above are preferably made of any one of inorganic oxides such as alumina, silica, mullite, zirconia, and calcium phosphate, silicon carbide, boron carbide, or silicon nitride.

    With such a configuration, the ceramic particles according to the present invention can be widely used for catalyst carriers, cell culture carriers, liquid chromatography fillers, and the like.

Among these, calcium phosphate is suitable for use as a liquid chromatography filler such as HPLC (High Performance Liquid Chromatography) because of its high adsorptivity to proteins and the like, and by using the ceramic particles 10 having the above-described configuration. A higher effect can be obtained as a filler. In addition, as calcium phosphate here, arbitrary calcium phosphates with a Ca / P ratio of 1.5 to 1.8 can be used, and tricalcium phosphate, hydroxyapatite, fluorapatite, and the like are included. When the ceramic particles 10 according to the present invention are made of calcium phosphate and used as a filler, the ceramic particles 10 preferably have a specific surface area of 10 m ² / g or more. For this reason, in the manufacturing method mentioned later, in order to raise the intensity | strength after baking, it is preferable that the calcium phosphate used as a raw material has a specific surface area of 50 m < ² > / g or more.

In addition, the skeleton part 30 which comprises the said open pore 20 needs to be comprised with the porous body. The specific surface area of the material constituting the skeleton portion 30 is, for example, ^{5 m} 2 / g or more ^{60 m} 2 / g or less.

    Next, the manufacturing method of the ceramic particle 10 concerning this embodiment is demonstrated using drawing. FIG. 3 is a process conceptual diagram for explaining the method for producing ceramic particles according to the present embodiment.

    First, a slurry (W) 50 containing ceramic powder, a binder, a dispersant, and pure water is prepared (FIG. 3A).

    As the ceramic powder used here, powders of inorganic oxides such as alumina, silica, mullite, zirconia, and calcium phosphate, silicon carbide, boron carbide, or silicon nitride are used. Moreover, agar can be used suitably for the binder used here. Moreover, the polyacrylic acid ammonium can be used for the dispersing agent used here, for example. The pure water here is generally used in the field of semiconductor manufacturing. Generally, industrial water, tap water, etc. are used as raw water, and impurities therein are used as high-purity ion exchange resins, high-performance membranes. For example, the specific resistance value of tap water used in general households is 0.01 to 0.05 MΩ · cm, whereas, for example, 1 MΩ · The one refined to cm or more.

    Next, the first oil 51 and a hydrophilic surfactant (not shown) are added to the slurry (W) 50, and a shear stress 52 is applied to the first oil 51 (FIG. 3 (b)).

    As the first oil 51 used here, normal paraffin, isoparaffin, hexadecane, or the like can be suitably used. Further, polyoxyethylene sorbitan monooleate can be suitably used as the hydrophilic surfactant. Further, the shear stress 52 can be given by a stirrer.

    In this way, by applying a shear stress 52 to the first oil 51, oil droplet particles (O) 53 composed of the first oil 51 are formed, and the oil droplet particles ( An O / W emulsion 54 in which O) 53 is dispersed is prepared (FIG. 3C).

    Next, a second oil (O) 55 containing a lipophilic surfactant is prepared, and the prepared O / W emulsion 54 is added into the second oil (O) 55, and the O / W is added. A shear stress 56 is applied to the emulsion 54 (FIG. 3 (d)).

    As the second oil 55 used here, normal paraffin, isoparaffin, hexadecane, or the like can be suitably used. Further, sorbitan sesquioleate can be suitably used as the lipophilic surfactant. Further, the shear stress 56 can be given by a stirrer.

    In this way, by applying a shear stress 56 to the O / W emulsion 54, the micro droplet (O / W) 57 composed of the slurry 50 in which the oil droplet particles (O) 53 are confined is formed. An O / W / O emulsion 58 in which the fine droplets (O / W) 57 are dispersed in the second oil (O) 55 is produced (FIG. 3E).

    Finally, the microdroplets (O / W) 57 are collected from the O / W / O emulsion 58, and the microdroplets (O / W) 57 are baked, so that the microdroplets (O / W) W) The ceramic particles according to the present invention in which the slurry (W) 50 in 57 is fired and the oil droplet particles (O) 53 are vaporized, and the portions of the oil droplet particles (O) 53 become the open pores 20. 10 can be manufactured.

The average pore diameter and the diameters O _t , R _t1 , and R _t2 of the open pores 20 are controlled by using the first oil 51, the type and amount of the hydrophilic surfactant, and the shear stress 52. It can be controlled by the strength of the.

    In addition, the porosity of the porous body in the skeleton 30 can be controlled by the particle size of the raw material used as the ceramic powder, the firing temperature, and the like.

    When agar is used as the binder in the process of manufacturing the ceramic particles 10, from the production of the slurry (W) 50 to the formation of the fine droplets (O / W) 57 in a heating environment (for example, 40 ° C. The above is preferable. As a result, fine droplets (O / W) 57 can be efficiently formed without the agar solidifying.

    In addition, a step of cooling the O / W / O emulsion 58 after forming the microdroplets (O / W) 57 and before collecting the microdroplets (O / W) 57 from the O / W / O emulsion 58. It is preferable to provide. As a result, after the microdroplet (O / W) 57 is formed, the agar contained in the microdroplet (O / W) 57 is solidified, whereby the entire microdroplet (O / W) 57 is gelled. Therefore, the shape is stabilized.

    Further, it is preferable to wash the gelled fine droplets (O / W) 57 using a solvent such as ethanol after the collection and before firing. As a result, the surfactant component contained in the microdroplet (O / W) 57 is removed, and the water contained in the microdroplet (O / W) 57 is replaced with the solvent. Accordingly, since the substituted solvent component can be vaporized at the time of firing, firing can be performed while the shape of the gelled microdroplet (O / W) 57 is stable.

    Moreover, you may perform a drying process after the washing | cleaning by the said solvent and before the said baking. In this drying process, for example, vacuum drying is performed under reduced pressure. Thereby, since the solvent component is removed before the firing, firing can be performed while the shape of the fine droplets (O / W) 57 is more stable.

    Moreover, you may perform the film processing which coats an oil-based component with respect to the said gelled microdroplet (O / W) 57 after the said solvent washing | cleaning and before the said drying process. By performing such a coating treatment, firing can be performed while the shape of the fine droplet (O / W) 57 is stabilized. As the oil component, normal paraffin, isoparaffin, hexadecane and the like can be suitably used.

    The ceramic particles 10 according to the present embodiment are prepared by producing the O / W emulsion 54 by the method described above, and then granulating the O / W emulsion 54 by spray drying to produce the granulated powder. It can also be produced by baking the powder.

Example 1
Hydroxyapatite powder is mixed at a ratio of 30% by weight with respect to the agar aqueous solution in an agar aqueous solution to which agar is added at a ratio of 0.5% by weight with respect to pure water. 5% by weight ratio with respect to the apatite powder was added, and mixed with a ball mill for 10 hours or more to prepare a hydroxyapatite-containing slurry.

    Next, 1% of polyoxyethylene sorbitan monooleate and 30% of isoparaffin with respect to pure water were added to the resulting slurry, and the mixture was stirred using a stirrer. By this stirring, isoparaffin was emulsified in the slurry to form oil droplet particles, and an apatite slurry in which the oil droplet particles were dispersed was produced.

    Next, isoparaffin and a surfactant (sorbitan sesquioleate: 4% by weight with respect to isoparaffin) are put into a beaker and stirred with a stirrer while heating. Apatite slurry with dispersed oil droplet particles was added little by little. By this stirring, fine droplets composed of a slurry in which oil droplet particles were confined inside were formed in the beaker.

    In addition, the process so far was performed in the environment which hold | maintains temperature at 40 degreeC or more so that the agar which is a binder may not harden | cure.

    Next, the beaker was cooled to gel the fine droplets formed. Thereafter, the gelled microdroplets were collected, washed with a solvent with ethanol, vacuum-dried under reduced pressure, and fired at 700 ° C.

    The obtained ceramic particles were classified to an average particle size of 80 μm to obtain a sample of Example 1.

(Comparative Examples 1-3)
Hydroxyapatite powder is mixed at a ratio of 30% by weight with respect to the agar aqueous solution in an agar aqueous solution to which agar is added at a ratio of 0.5% by weight with respect to pure water. 5% by weight ratio with respect to the apatite powder was added, and mixed with a ball mill for 10 hours or more to prepare a hydroxyapatite-containing slurry.

    Next, without forming oil droplet particles as shown in Example 1, isoparaffin and surfactant (sorbitan sesquioleate: 4% by weight with respect to isoparaffin) were put into a beaker and heated with a stirrer. The slurry thus prepared was added little by little in a beaker while stirring. By this stirring, fine droplets composed of a slurry in which oil droplet particles were not confined in the beaker were formed.

    In addition, the process so far was performed in the environment which hold | maintains temperature at 40 degreeC or more so that the agar which is a binder may not harden | cure.

    Next, the beaker was cooled to gel the fine droplets formed. Thereafter, the gelled microdroplets were collected, washed with a solvent with ethanol, vacuum-dried under reduced pressure, and fired at 700 ° C.

    The obtained ceramic particles were classified into average particle diameters of 80 μm, 60 μm, and 40 μm to obtain samples of Comparative Examples 1, 2, and 3, respectively.

    Next, a protein separation property test was performed on the samples prepared in Example 1 and Comparative Examples 1 to 3.

(Protein separation property test)
The protein separation property test was performed using a high performance liquid chromatograph (Hitachi Lachorm L-7000). The eluent, protein sample, empty column, filler slurry and test conditions used in the analysis are as follows.

    As the eluent, 1 mM sodium phosphate buffer and 400 mM sodium phosphate buffer were used. All eluents were adjusted to pH 6.8. As the protein sample, albumin, liposome, cytochrome-C was used, and a protein sample solution containing 0.03 mM of each protein was used. A 1 mM sodium phosphate buffer was used as a solvent for the protein sample solution. As the empty column, a stainless steel column of φ2 mm × 150 mm was used.

    As the filler slurry, 0.3 g of various fillers diluted with 400 mM sodium phosphate buffer to a particle concentration of 10 wt% was used. In addition, an empty column equipped with a packer was installed in a high performance liquid chromatography apparatus, and a column was filled with a filler slurry, and a column was filled with 1 mM sodium phosphate buffer at a flow rate of 2 mL / min.

    For protein separation characterization, the eluent was flowed at a flow rate of 1 mL / min. The eluent was linearly changed from 1 mM to 200.5 mM (1 mM (50%) + 400 mM (50%)) over 15 minutes after flowing 1 mM sodium phosphate buffer for 5 minutes.

    FIG. 4 shows the evaluation results of the separation characteristics in Example 1, and FIGS. 5 to 7 show the evaluation results of the separation characteristics in each comparative example.

    From the results of Comparative Examples 1 to 3 (FIGS. 5 to 7), it can be seen that the smaller the particle size, the better the protein separation performance. That is, it can be seen that the peaks of albumin 21 and lysozyme 22 are separated as the particle size decreases. This is presumably because the specific surface area increased and the contact area with the eluent increased because the particle size became smaller. In Comparative Example 1 (FIG. 5) having an average particle size of 80 μm, it can be confirmed that albumin 21 and lysozyme 22 are not separated.

    On the other hand, in Example 1 (FIG. 4), it can be confirmed that the peaks of albumin 21 and lysozyme 22 are largely separated although the average particle diameter is the same as that of Comparative Example 1.

    An SEM photograph of the ceramic particles before classification to an average particle size of 80 μm produced in Example 1 is shown in FIG.

As shown in FIG. 8, the ceramic particles produced in Example 1 have an average pore diameter of 500 nm or more and 40 μm or less from the outer surface to the inside, and a plurality of apertures and communication portions having a diameter of 300 nm or more and 10 μm or less. It can be confirmed that open pores are provided. That is, the result of the protein separation characteristic test is presumed to be due to the plurality of open pores formed in the ceramic particles. The ceramic particles in Comparative Examples 1 to 3 did not have a plurality of open pores as confirmed in Example 1. In addition, it was 30 m < ² > / g, when the specific surface area of the frame part of the ceramic particle in Example 1 and Comparative Examples 1 to 3 was measured.

(Comparative Example 4)
The amount of isoparaffin used in forming the oil droplet particles and the strength of the stirrer were adjusted to form oil droplet particles smaller than in Example 1. Otherwise, ceramic particles were produced in the same manner as in Example 1.

    When the protein separation characteristic test was performed on the sample prepared in Comparative Example 4 in the same manner as in Example 1, protein separation performance at the same level as in Comparative Example 2 was confirmed. In addition, when the open pores of the ceramic particles at this time were evaluated, the apertures of the open pores and the diameter of the communicating portion were each 200 nm or less, and no ceramic particles having an aperture of the opening and the communicating portion exceeding 300 nm were confirmed. It was.

(Example 2)
The amount of isoparaffin used when forming the oil droplet particles and the strength of the stirrer are adjusted to form oil droplet particles larger than that of Example 1, and the particle size of the ceramic particles is larger than that of Example 1. In addition, ceramic particles were prepared in the same manner as in Example 1 except that the strength of the stirrer was adjusted when forming fine droplets. Thereafter, the obtained ceramic particles were classified to an average particle size of 200 μm to obtain a sample of Example 2.

    The sample produced in Example 2 was subjected to a protein separation property test in the same manner as in Example 1. As a result, protein separation performance equivalent to that in Example 1 was confirmed. In addition, when the open pores of the ceramic particles at this time were evaluated, a plurality of open pores having an average pore diameter of 25 μm or more and 50 μm or less from the outer surface to the inside thereof, and a diameter of the opening or the communication portion of 10 μm or more and 20 μm or less. Was confirmed.

(Comparative Example 5)
The amount of isoparaffin used in forming the oil droplet particles and the strength of the stirrer were adjusted to form larger oil droplet particles than in Example 2. Otherwise, ceramic particles were produced in the same manner as in Example 2.

    When the obtained ceramic particles were confirmed by SEM photographs, the particle size of the obtained ceramic particles was very small compared to Example 2, and there were some chipping and cracking of the ceramic particles, and the ceramic particles themselves were destroyed. Many things have been confirmed. In addition, when the open pores of the broken ceramic particles were evaluated, it was confirmed that the diameters of the opening portions and the communicating portions of the open pores exceeded 20 μm.

(Example 3)
Ceramic particles were produced in the same manner as in Example 1 except that alumina powder was used instead of hydroxyapatite powder.

    As a result, like Example 1, it has a plurality of open pores having an average pore diameter of 500 nm to 40 μm from the outer surface to the inside thereof as shown in FIG. Ceramic particles could be obtained.

Example 4
Ceramic particles were prepared in the same manner as in Example 1 except that silica powder was used instead of hydroxyapatite powder.

    As a result, like Example 1, it has a plurality of open pores having an average pore diameter of 500 nm to 40 μm from the outer surface to the inside thereof as shown in FIG. Ceramic particles could be obtained.

(Example 5)
Ceramic particles were prepared in the same manner as in Example 1 except that mullite powder was used instead of hydroxyapatite powder.

    As a result, like Example 1, it has a plurality of open pores having an average pore diameter of 500 nm to 40 μm from the outer surface to the inside thereof as shown in FIG. Ceramic particles could be obtained.

(Example 6)
Ceramic particles were produced in the same manner as in Example 1 except that zirconia powder was used instead of the hydroxyapatite powder.

    As a result, like Example 1, it has a plurality of open pores having an average pore diameter of 500 nm to 40 μm from the outer surface to the inside thereof as shown in FIG. Ceramic particles could be obtained.

(Example 7)
Ceramic particles were produced in the same manner as in Example 1 except that silicon carbide powder was used instead of the hydroxyapatite powder.

    As a result, like Example 1, it has a plurality of open pores having an average pore diameter of 500 nm to 40 μm from the outer surface to the inside thereof as shown in FIG. Ceramic particles could be obtained.

(Example 8)
Using each of alumina powder, silica powder, mullite powder, zirconia powder, and silicon carbide powder, the amount of isoparaffin used in forming the oil droplet particles and the strength of the stirrer are adjusted, so that the oil droplet particles are larger than in Example 1. In addition, the strength of the stirrer when forming the fine droplets is adjusted so that the particle size of the ceramic particles is larger than that of Example 1, and the others are the same as in Example 1. Ceramic particles were prepared for each powder. Thereafter, the obtained ceramic particles were each classified to an average particle size of 200 μm to obtain a sample of Example 8.

    When the open pores of the ceramic particles of each powder obtained at this time were evaluated, the average pore diameter was 25 μm or more and 50 μm or less from the outer surface to the inside of all the ceramic particles. A plurality of open pores of 10 μm or more and 20 μm or less were confirmed.

    The ceramic particles according to Examples 3 to 8 produced as described above can be suitably used for catalyst carriers and the like.

    In addition, this invention is not limited to embodiment mentioned above. Various other modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 10 ... Ceramic particle 10a ... Outer surface 20 ... Open pore 20a ... Surface open pore 20b ... Internal open pore 20c ... Internal open pore

Claims (5)

Ceramic particles having a plurality of open pores on the outer surface,
The open pores have an average pore diameter of 500 nm or more and 50 μm or less,
The diameter of the opening on the outer surface of the open pore is 300 nm or more and 20 μm or less,
Ceramic particles characterized in that the skeleton part constituting the open pores is constituted by a porous body. Ceramic particles having a plurality of open pores on the outer surface,
The open pores are surface open pores having an average pore diameter of 500 nm or more and 50 μm or less provided on the outer surface;
An internal pore having an average pore diameter of 500 nm or more and 50 μm or less provided in communication with the inner wall surface of the surface open pore;
The aperture of the outer surface of the surface open pores and the aperture of the communication portion between the surface open pores and the internal open pores are 300 nm or more and 20 μm or less,
Ceramic particles characterized in that the skeleton part constituting the open pores is constituted by a porous body.   The ceramic particles according to claim 1 or 2, wherein the open pores are provided so as to communicate from one outer surface of the ceramic particles to the other outer surface.   The ceramic particle according to any one of claims 1 to 3, wherein the ceramic particle is any one of an inorganic oxide, silicon carbide, boron carbide, and silicon nitride. A first oil and a hydrophilic surfactant are added to a slurry (W) containing ceramic powder, a binder, a dispersant, and pure water, and a shear stress is applied to the first oil, whereby the first oil is added. Forming oil droplet particles (O) composed of the oil of, and producing an O / W emulsion in which the oil droplet particles (O) are dispersed in the slurry (W);
The O / W emulsion is added to a second oil (O) containing a lipophilic surfactant, and the oil droplet particles (O) are confined inside by applying shear stress to the O / W emulsion. A fine droplet (O / W) composed of a slurry is formed, and an O / W / O emulsion in which the fine droplet (O / W) is dispersed in the second oil (O) is produced. Process,
Firing the fine droplets (O / W);
A method for producing ceramic particles, comprising: