KR20140104534A - Method for manufacturing porous ceramics material and porous ceramics material using thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a porous ceramics material, including a mixing step in which a mixed liquid is produced by mixing ceramic powder and cement with an aqueous solution; a suspension forming step in which a suspension is formed by injecting an amphipathic material-containing surface treatment agent into the mixed liquid; a pore forming step in which the suspension is stirred to inject air, and pores are formed through interaction between the suspension and the air; and a hydration step in which a porous ceramic material is formed by self-hardening through reaction between the cement and water. According to the present invention, hydrophobicity is effectively provided on a ceramic particle surface, and thus the pores can be simply formed through interaction between air hydrophobicity and water hydrophilicity. Also, the cement is added as a material constituting the porous ceramics material, and thus the hardening can be simplified and facilitated, even without a sintering process, through the hydration reaction between the cement and the water.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a porous ceramics material,

The present invention relates to a method for producing a porous ceramic material and a porous ceramic material produced by the method. More particularly, the present invention relates to a porous ceramic material produced by effectively imparting hydrophobicity to the surface of ceramic particles, The present invention relates to a method for manufacturing a porous ceramic material by a simple process of autocuring without adding a cement to a pore size and a distribution of the pore.

 As shown in FIG. 1, porous ceramics refers to a solid having pores having various sizes in a solid such as a particle or a bill, and refers to a porous body, a porous solid, or a porous material.

When these porous bodies are classified into a geometric structure, they can be roughly classified into an aggregate type, a sponge type (or a foam type), and a honeycomb type. Aggregates or agglomerates are sintered fine particles or solidified as binders. The pores are generated from macro pores existing between the particles in addition to the internal micro pores of the raw particles, The size of the voids present between the particles is related to the size of the raw particles.

Particularly, in the conventional porous ceramics, a certain amount of a flux component is mixed with a ceramics aggregate in which the particle size distribution is controlled to a certain range of width, and the mixture is sintered at a high temperature to burn the flux. The size of the pores is about 1 mm to about 1 mm Depending on the material and pore size, it has been used in a wide range of applications such as filtration or diffusion filters, bioceramics medium catalyst stages, sound absorbers, diesel particulate filters (DPF), heat exchangers, special heaters and thermal insulation finishes.

The method of producing such porous ceramics is a method in which a pore forming agent having a predetermined particle size is mixed and then introduced into a sintering process and an aggregate of a predetermined particle size is uniformly coated with an organic or inorganic adhesive flux, A compression molding method in which molding is performed, followed by drying and firing, and a template injection molding method in which molding is performed using a natural template and then firing is used.

However, the conventional production method has a problem that it is difficult to maintain the stable shape of the particles during the drying process, and the size of the pores, the cost of production, the heat insulation for high temperature and the microstructure adjustment technique of the open pores for preventing condensation, The shape and the distribution diagram could not be effectively controlled. Also, when the porous ceramics were applied as an adiabatic finishing material, it was impossible to apply spray coating method to the inside / outside wall and floor construction of various buildings due to the sintering process.

Therefore, in the production of porous ceramics, it is required to develop a technique for simplifying the manufacturing process and improving the uniform distribution of porosity and porosity.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the problems of the prior art described above and it is an object of the present invention to provide a method of effectively applying hydrophobicity to the surfaces of ceramic particles, It is an object of the present invention to provide a method for manufacturing a porous ceramic material which can easily form pores by interaction between hydrophobicity and hydrophilicity of water.

In addition, by optimizing the kinds and proportions of the ceramic powder and the surface treatment agent, the surface of the ceramic powder is surrounded by the hydrophilic group of the surface treatment agent containing the amphipathic substance, thereby forming a reversed micellar ceramic composite body It is an object of the present invention to provide a method of manufacturing a porous ceramic material capable of uniformly distributing pores and maximizing porosity.

Further, by explaining the relationship between the pore size and the morphological stability of the porous ceramics material in forming a wet foam by optimizing the constituent materials, the composition ratio and the concentration, and the pores being surrounded by the ceramic layer, And a method of manufacturing a porous ceramic material which can effectively control the shape and distribution of the porous ceramic material.

It is another object of the present invention to provide a method for manufacturing a porous ceramic material which is cured without causing sintering process by causing hydration reaction of cement and water by adding cement as a constituent material of a porous ceramic material.

In order to achieve the above object, a method of manufacturing a porous ceramic material according to an embodiment of the present invention includes mixing a ceramic powder and cement with an aqueous solution to prepare a mixed solution, mixing the mixed solution with a surface treatment agent containing an amphipathic substance A step of forming a suspension to form a suspension; a step of pouring a suspension of the suspension to form a wet compact having pores formed by the interaction of the suspension and the air by injecting air; And the wet molded article is autocured to form a cured molded article.

In the suspension forming step, a reversed micelle type ceramic composite body is formed with the hydrophobic surface of the surface treatment agent as a center, with the ceramic powder as a center, and in the pore forming step, Air bubbles are surrounded by the ceramic composite body to form a ceramic layer, thereby forming a wet molded body.

Wherein the ceramic powder comprises at least one of alumina, silica, titanium oxide, calcium phosphate, hydroxyapatite or silicon carbide, the ceramic powder comprises the alumina and the silica, the molar ratio of the alumina to the silica is 1: 0.2 to 1: 0.5.

The cement is characterized in that the ceramic powder is 10 to 35% by volume based on 100% by volume of the cement.

The aqueous solution contains sodium chloride, and the concentration of sodium chloride is 0.005 to 0.5 mol / L.

In the mixing step, the mixture preferably further comprises lithium carbonate, and it is effective that the lithium carbonate is 15 to 25% by volume based on 100% by volume of the ceramic powder, the cement and the lithium carbonate.

In the suspension forming step, the amphipathic substance includes at least one of propyl gallate, butyl gallate, hexylamine, butyric acid or valeric acid, and the concentration of the surface treatment agent is 0.01 to 0.1 mol / L .

In the suspension forming step, it is effective that the pH of the suspension is 9 to 10, and the contact angle of the suspension is 60 to 90 degrees.

The ceramic powder is 15 to 50 parts by weight based on 100 parts by weight of the suspension.

A preferred embodiment comprises a drying step after the pore forming step, drying at a temperature of 15 to 35 DEG C for 10 to 60 minutes.

The hydration reaction step is characterized in that the hydration is carried out at a temperature of 20 to 90 DEG C and a humidity of 35 to 90%.

And a porous ceramic material produced by the above production method.

According to the method for producing a porous ceramics material of the present invention, one or more of the following effects can be obtained.

First, there is an advantage that the surface of the ceramic powder can be treated with a surface treatment agent containing an amphipathic substance to effectively impart hydrophobicity to the surface of the ceramic particles.

Second, by using the interaction between the hydrophobicity of air and the hydrophilicity of water, a wet molded body surrounded by pores can be formed by the ceramic particles having hydrophobicity on the surface, so that the size, shape and distribution of pores can be effectively controlled.

Third, there is an advantage in that the type, ratio and concentration of the ceramic powder, cement, aqueous solution and surface treatment agent, which are materials used in the production of the porous ceramic material, are optimized to have high stability and a porosity of 65% or more.

Fourth, since the porous ceramics material is self-generated by the curing phenomenon by hydration reaction with water using cement, unlike the conventional method, the sintering process is not necessary, which is economical and advantageous in that the manufacturing process is simplified.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 is a flowchart sequentially illustrating a method of manufacturing a porous ceramic material according to an embodiment of the present invention.
FIG. 2 is a schematic view illustrating hydrophobization of a ceramic powder according to an embodiment of the present invention.
3 is a graph showing the zeta potential of the ceramic powder used in the manufacturing method of one embodiment of the present invention.
4 is a schematic view showing a method of manufacturing a porous ceramic material according to an embodiment of the present invention.
FIG. 5 is a schematic view showing pores in a wet formed body according to an embodiment of the present invention in a Laplace type between pores and a wet formed body.
FIG. 6 is a graph showing the stability of? P and a wet molded article according to the concentration of a surface treatment agent according to an embodiment of the present invention.
FIG. 7 is a graph showing the stability of ΔP and a wet molded article according to the concentration of solid matter of ceramic powder and cement according to an embodiment of the present invention.
8 is a graph showing the contact angle and surface tension according to the concentration of the surface treatment agent according to an embodiment of the present invention.
9 is a graph showing a curing time according to the content of cement or lithium carbonate in the hydration reaction step according to an embodiment of the present invention.
10 is a microstructure of a porous ceramic material produced according to an embodiment of the present invention in accordance with a molar ratio of alumina and silica.
11 is a microstructure of a porous ceramic material produced according to the content of lithium carbonate according to an embodiment of the present invention.
12 is a microstructure of a porous ceramic material produced according to the content of cement according to an embodiment of the present invention.
13 is a graph showing compressive strength and porosity of a porous ceramic material produced according to an embodiment of the present invention.
14 is a microstructure of the porous ceramic material produced according to the drying method of the hydration reaction according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising ", as used herein, unless the recited component, step, and / or step does not exclude the presence or addition of one or more other elements, steps and / I never do that.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

In the drawings, the thickness and the size of each component are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Hereinafter, the present invention will be described with reference to the drawings for explaining a method of manufacturing a porous ceramic material according to embodiments of the present invention.

1, a method of manufacturing a porous ceramic material according to an embodiment of the present invention includes a mixing step S10, a suspension forming step S20, a pore forming step S30, and a hydration reaction step S50 .

The mixing step S10 is a step of mixing a ceramic powder and cement with an aqueous solution to prepare a mixed solution. This is a step of adding a ceramic powder to an aqueous solution, and is a preliminary step for performing surface treatment on each particle of the ceramic powder in the future.

Here, the ceramic powder means a ceramic in the form of a powder, and is composed of small particles smaller than 1 cm. The ceramic powder may be any kind of ceramic. However, in order to realize the optimum effect in the present invention, it is preferable to use a ceramic powder such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), titanium oxide (TiO ₂ ) It is preferable to include at least one of hydroxyapatite or silicon carbide (SiC), more preferably at least one of silica, titanium oxide or hydro-apatite in alumina is effective, and most preferably, It is most effective to include silica. When the ceramic powder is composed of alumina and silica, the molar ratio of alumina to silica is preferably 1: 0.2 to 1: 0.5, more preferably 1: 0.2 to 1: 0.4. When the molar ratio of alumina to silica is less than or equal to 1: 0.2, pores are formed non-uniformly, resulting in poor physical properties as a ceramic material.

In the mixing step (S10), the aqueous solution is a solution in which water is used as a solvent. The solute may be variously applied depending on the type of the ceramic. In the present invention, however, the use of sodium chloride results in a fast and even surface It is effective for treatment.

The concentration of sodium chloride is preferably 0.005 to 0.5 mol / L, more preferably 0.008 to 0.2 mol / L, and most preferably 0.1 mol / L. When the concentration of sodium chloride is less than 0.005 mol / L, the effect of improving the surface treatment reaction is insignificant. When the concentration exceeds 0.5 mol / L, the surface treatment reaction is rather disturbed.

Cement is added in order to realize a porous ceramics material by autocuring through water and hydration reaction. There are no limitations on the type of cement, but regulated-set cement and calcium aluminate cement, which are fast-curing cements, can be used as additive such as setter due to rapid high-temperature hydrothermal reaction during curing. CAS (Calcium Sulpho Aluminate) based cement which can obtain both speed, shrinkage and high strength at the same time is effective because there is a problem to be used. CAS cement is capable of exhibiting fast velocity, no shrinkage, and high strength due to the stable expansion of the etringgite of the needle crystal formed by the reaction of aluminate and gypsum in cement during hydration.

The cement is preferably 10 to 35% by volume, more preferably 20 to 25% by volume, based on 100% by volume of the solid matter of the ceramic powder and the cement. When the cement content is less than 10% by volume, the self-curing time is long and the compressive strength is low. When the cement content is more than 35% by volume, the cement content is high and it is difficult to realize a lightweight ceramics material.

In order to promote hydration reaction of cement, it is preferable to further include lithium carbonate (Li ₂ CO ₃ ). The following formula promotes the hydration reaction of lithium carbonate.

[Chemical Formula 1]

Li ⁺ + 2AlO ₂ ^- + 6H ₂ O -> LiH (AlO ₂ ) ₂ .5H ₂ O + OH ^-

By the reaction of the formula (1), lithium carbonate plays a role in shortening the curing time of the porous ceramic material in the hydration reaction step (S50).

The lithium carbonate is preferably 15 to 25% by volume based on 100% by volume of the ceramic powder, cement and lithium carbonate. Within the above range, the curing time can be effectively shortened during the hydration reaction, and the crystals of the porous ceramic material are not only finely developed in an acicular shape but also have a problem that the content of lithium carbonate is uneconomical.

Next, as shown in FIG. 2, the suspension forming step S20 is a step of adding a surfactant to the mixed solution prepared in the mixing step S10 to prepare a suspension. This is a surface treatment process for changing the contact angle of ceramic, especially alumina surface, from hydrophilic to hydrophobic.

Preferably, the surface treatment agent includes an amphipathic substance, and more preferably, it is selected from the group consisting of propyl gallate, butyl gallate, hexyl amine, butyric acid or valeric acid valeric acid, and more preferably, it is effective to use propyl gallate.

The hydrophilic portion of the surface treatment agent containing the amphipathic substance forms a layer of a hydrophilic ceramic surface to form a reverse micelle ceramic composite in which the hydrophobic portion of the surface treatment agent is exposed to the surface, Change it to be hydrophobic from the outside.

The concentration of the surface treatment agent is preferably 0.01 to 0.1 mol / L, more preferably 0.03 to 0.07 mol / L, and most preferably 0.05 mol / L. When the concentration of the surface treatment agent is less than 0.01 mol / L, a portion of the ceramic surface can not be changed to be hydrophobic, and the effect of surface treatment is lowered. As a result, the pore-forming efficiency is remarkably lowered and the stability of the formed porous ceramic material is drastically decreased There is. On the contrary, when the concentration of the surface treatment agent exceeds 0.1 mol / L, the presence of a large number of surface treatment agent particles that can not be adhered to the ceramic remarkably lowers the physical properties of the formed porous ceramic material, There is a problem that the stability of the ceramics material is remarkably low.

The suspension formed in the suspension forming step (S20) preferably has a pH of 9 to 10, more preferably a pH of 9.5 to 9.9. If the pH of the suspension is less than 9, the size of the pores becomes large, which may be a problem. If the pH is more than 10, there is a problem that the stability of the formed porous ceramic material becomes poor. As shown in FIG. 3, when the alumina and silica were used as the ceramic powder, the zeta potentials according to the pH changes were measured. When the pH value was 9 to 10, The surface charge balance of alumina and silica is adjusted to have a negative charge, and optimum dispersion can be achieved by repulsion between ceramic powder particles.

Further, the contact angle of the suspension is preferably 60 to 90 DEG, more preferably 65 to 75 DEG. When the contact angle is less than 60 DEG, the stability of the porous ceramic material to be formed not only sharply decreases but also the pore size becomes excessively small. When the contact angle exceeds 90 DEG, the treatment is practically difficult. Is significantly increased.

The viscosity of the suspension is preferably 2000 to 2300 mPas, and the surface tension is preferably 21 to 25 mN / m.

The content of the suspension and the ceramic powder is preferably 15 to 50 parts by weight, more preferably 20 to 40 parts by weight, most preferably 30 parts by weight, of the ceramic powder per 100 parts by weight of the suspension. If the amount of the ceramic powder is less than 15 parts by weight, a part of the ceramic surface can not be converted to a hydrophobic property, and the surface treatment effect is lowered. In addition, the pore formation efficiency is lowered and the stability of the formed porous ceramic material is drastically reduced. When the amount is more than 50 parts by weight, there are many particles of the surface treatment agent that can not adhere to the ceramic to lower the physical properties of the formed porous ceramic material, lower the porosity formation efficiency, and lower the stability of the formed porous ceramic material.

Next, the pore forming step (S30) is a step of forming a wet formed body in which pores are formed by the reaction of the suspension and the air by pouring air by stirring the suspension. In the reaction step for forming pores in the ceramic material to be.

As shown in FIG. 4, by stirring the suspension, external air is injected into the suspension, and the introduced hydrophobic air reacts with hydrophilic water to form pores. That is, air is injected into the suspension to generate a large number of air bubbles, and the ceramic composite surface-treated with hydrophobicity is surrounded by the air bubbles, and a ceramic layer is formed on the outer side of the air bubbles to form a wet foam.

Here, according to the Laplace equation, the external pressure of the air bubbles formed by introducing the air in the air during the stirring of the suspension containing the ceramic powder subjected to the hydrophobic surface treatment with the surface treatment agent, the radius of the air bubbles, Knowing the surface tension of the surface-treated ceramic can determine the internal pressure of air bubbles. The size of the air bubble is adjusted to be larger or smaller by using this, and the stability of the wet molded article can be determined according to the pressure difference (ΔP) between the external pressure and the internal pressure. The Laplace equation and a schematic diagram explaining this are shown in FIG.

Therefore, a ceramic layer is formed around air bubbles to easily form pores, and stabilization of the wet molded body such as size, shape, and distribution of pores can be easily controlled through control of air injection according to stirring speed and time. In addition, by optimizing these process conditions, the stability of the formed porous ceramic material can be improved.

In the pore forming step (S30), stirring may be carried out in any manner, and it is effective to carry out the stirring with a stirrer for 2 to 10 minutes, more preferably for 3 to 5 minutes.

Next, in one embodiment of the present invention, it is preferable that the drying step (S40) is performed before the hydration reaction step (S50) after the pore forming step (S30).

The drying step S40 is a step of drying the wet formed body formed in the pore forming step S30 into the air. The drying temperature is preferably 15 to 35 占 폚, more preferably 20 to 25 占 폚. The drying time is preferably 20 to 50 hours, more preferably 24 to 48 hours.

Finally, the hydration reaction step (S50) is a step in which the humidity of the molded body is subjected to constant temperature and humidity at 25 to 50% in the drying step (S40), thereby realizing a stable type ceramic material. The cement is hardened by water hydration reaction with water and forms a cured molded article. Therefore, the porous ceramic material can be easily manufactured through an economical and simple reaction without a separate sintering process. The hydration reaction must be carried out under a certain humidity condition so that the ceramics material can be cured while having a needle-like and dense structure, and it is preferable to perform the hydration reaction at a humidity of 35 to 90%.

The hydration reaction in the hydration reaction step (S50) is represented by the following formula (2).

(2)

2CaSiO _{5 (cement) + 7H 2 O → 3CaO ·} 3SiO 2 · 4H 2 O + 3Ca (OH) 2 + 173.6kJ

The hydration reaction temperature is preferably 25 to 90 DEG C, more preferably 30 to 50 DEG C, most preferably 35 DEG C, and more preferably at a temperature higher than the drying step (S40). The hydration reaction time is effectively 1 to 15 days, more preferably 3 to 5 days.

Hereinafter, experimental results for demonstrating the superiority of the porous ceramic material produced by the method for producing a porous ceramic material of the present invention will be described.

First, the structural stability of the pores formed in the wet molded body during the manufacturing process according to one embodiment of the present invention is based on the principle as shown in FIGS.

FIG. 6 shows the results of an experiment on the change of pressure (? P) according to the concentration of the surface treating agent and the stabilization of the wet molded article. The? P changes from 0.4 mPa to 2.0 mPa when the concentration of the surface treating agent is 0.001 to 1.0 mol / When the concentration of the surface treatment agent is about 1.0 mol / L, the ΔP rapidly increases to 2.0 mPa, and the stabilization of the wet molded body is drastically lowered from 80% to 40%. That is, it can be seen that when the surface treatment agent is 0.01 to 0.1 mol / L, the stability of the wet molded article is high and pores can be formed with a P of 0.2 to 0.6 mPa.

7 shows the results of experiments on the change of pressure (ΔP) and the stabilization of the wet compacted body according to the concentration of solid powder of ceramic powder and cement, wherein the paraxial concentration on the horizontal axis means the concentration of the solid matter of the ceramic powder and cement, 100% by volume. When the concentration is 10 vol.% To 35 vol.%, The magnitude of? P changes from 0.2 mPa to 1.0 mPa. When the concentration is about 30 vol%, the magnitude of? P is 0.6 mPa and the wetted body stabilization is 80% Is increased to 35% by volume, the stabilization of the wet molded article is reduced to 75%. In other words, it can be seen that excellent porosity ceramic material can be realized when the solid content of the ceramic powder and cement is 20 to 30% by volume in view of the stability of the wet molded article and the magnitude of? P.

8 shows the results of the contact angle of the suspension and the surface tension of the suspension depending on the content of the surface treatment agent. As a result of the contact angle and surface tension of the suspension depending on the concentration of the surface treatment agent, the concentration of the surface treatment agent was changed from 0.001 mol / L to 0.1 mol / L The contact angle of the suspension increased from 74 ° to 85 °, and when the concentration of the surface treatment agent was 1.0 mol / L, the contact angle decreased remarkably from 85 ° to 60 °, where the surface tension increased from 57 mN / m to 53 mN / m. Also, as the concentration of the surface treatment agent increases from 0.001 mol / L to 0.1 mol / L, the surface tension decreases from 75 mN / m to 53 mN / m. The contact angle is affected by the surface tension between the liquid and the solid. The higher the surface tension of the solid, the higher the wettability of the water and the smaller the contact angle. The smaller the contact angle, the greater the hydrophilicity and the better the wettability. That is, the surface treatment agent preferably has a concentration of 0.001 to 0.1 mol / L, more preferably 0.01 to 0.1 mol / L in order to have an optimal contact angle of 70 to 85 DEG for hydrophobic surface treatment of the ceramic surface .

Fig. 9 shows autocure after hydration reaction depending on the amount of cement and the amount of lithium carbonate, which is a hydration reaction promoter. For cement and lithium carbonate, a solid material such as a ceramic powder is used as 100. Here, cement was tested using Portland cement using Ca ₃ SiO ₅ . As the amount of Portland cement was increased from 10 to 30% by volume, autocuring was significantly reduced from 18 days to 2 days. As the lithium carbonate was increased to 0 to 10% by weight, the hydration reaction time was shortened from 15 days to 3 days . As the content of cement increases, the effect of hydration reaction is excellent, but in order to realize a lightweight ceramics material, it is preferably 15 to 25% by volume. In the case of lithium carbonate, 3 to 15 mass% is preferably added.

10 is a microstructure of a porous ceramic material according to a content ratio (molar ratio) when a ceramic powder is composed of alumina and silica. 0.1mol / L of the surface treatment agent was added. As the molar ratio of alumina to silica increased from 1: 0 to 1: 0.5, the pore size was controlled to about 100 to 300 μm, and the most uniform pore distribution was obtained when the molar ratio was 1: 0.25. (d), the ceramic layer between the pores can be seen as a single layer or a double layer.

11 shows the microstructure of the porous ceramic material according to the lithium carbonate content. The content of lithium carbonate represents the volume percentage with respect to the solid material such as ceramic powder, cement, lithium carbonate and the like. When the lithium carbonate was 15 to 25% by volume, it was possible to observe well-developed acicular cement crystals around the pores. When the volume ratio of lithium carbonate was 20 vol%, the acicular type crystals were most well developed. It is possible.

12 shows the microstructure of the porous ceramic material according to the cement content. Portland cement was used for cement, and 15% by volume of alumina and 10% by weight of lithium carbonate were used for 100 of solid water such as ceramic powder, cement and lithium carbonate. When the content of cement is 10 to 35% by volume, the fine structure is well developed, and the pore size of spherical shape is 100 to 300 탆. When the cement is 25 vol% with respect to 100 vol% of solid matter such as ceramic powder, cement, lithium carbonate, etc., it is possible to produce a porous ceramic material having an excellent microstructure.

13 shows the compressive strength and porosity according to Portland cement content. As the content of cement increased from 10 vol% to 30 vol%, the compressive strength increased from 4 mPa to 10 mPa, and the porosity decreased from 75% to 40% as the amount of cement was increased.

14 is a microstructure of the porous ceramic material according to the drying method after the hydration reaction. (B) when the moisture content of the cement is 25% by volume based on 100% by volume of the solid material such as ceramic powder, cement or lithium carbonate, (b) Hydration reaction is well done, and it is possible to confirm the needle-shaped crystal structure well developed around the pore.

The scope of the present invention is not limited to the above-described embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (18)

A mixing step of mixing the ceramic powder and the cement with an aqueous solution to prepare a mixed solution;
A suspension forming step of adding a surface treatment agent containing an amphipathic substance to the mixed solution to form a suspension;
A pore forming step of pouring air by stirring the suspension to produce a wet formed body in which pores are formed by interaction between the suspension and the air; And
And a hydration reaction step in which the wet compact is autocured by reaction of the cement and water to form a cured compact. The method according to claim 1,
And forming a reversed micelle-type ceramic composite body with the hydrophobic surface of the surface treatment agent as a surface, with the ceramic powder as a center, in the present step of forming the carbonaceous fluid. The method according to claim 1,
Wherein in the pore-forming step, the wet-molded body is formed by forming a ceramic layer surrounded by the ceramic composite body with air bubbles generated in the suspension by the air being injected thereinto. 4. The method according to any one of claims 1 to 3,
Wherein the ceramic powder comprises at least one of alumina, silica, titanium oxide, calcium phosphate, hydroxyapatite or silicon carbide. 5. The method of claim 4,
Wherein the ceramic powder comprises the alumina and the silica, and the molar ratio of the alumina to the silica is 1: 0.2 to 1: 0.5. The method according to claim 1,
Wherein the cement is 10 to 35% by volume of the ceramic powder and 100% by volume of the cement. 4. The method according to any one of claims 1 to 3,
Wherein the aqueous solution comprises sodium chloride. 8. The method of claim 7,
Wherein the concentration of the sodium chloride is 0.005 to 0.5 mol / L. The method according to claim 1,
In the mixing step, the mixture further comprises lithium carbonate. 10. The method of claim 9,
Wherein the lithium carbonate is present in an amount of 15 to 25% by volume based on 100% by volume of the ceramic powder, the cement and the lithium carbonate. 4. The method according to any one of claims 1 to 3,
Wherein the amphipathic material comprises at least one of propyl gallate, butyl gallate, hexyl amine, butyric acid or valeric acid in the suspension forming step. 4. The method according to any one of claims 1 to 3,
Wherein the concentration of the surface treating agent in the suspension forming step is 0.01 to 0.1 mol / L. 4. The method according to any one of claims 1 to 3,
Wherein the suspension has a pH of 9 to 10 in the suspension forming step. 4. The method according to any one of claims 1 to 3,
Wherein in the suspension forming step, the contact angle of the suspension is 60 to 90 °. 4. The method according to any one of claims 1 to 3,
Wherein the ceramic powder is 15 to 50 parts by weight based on 100 parts by weight of the suspension. The method according to claim 1,
And drying the porous ceramic material at a temperature of 15 to 35 DEG C for 10 to 60 minutes after the pore forming step. The method according to claim 1,
Wherein the hydration reaction step is carried out by a hydration reaction at a temperature of 20 to 90 占 폚 and a humidity of 35 to 90%. A porous ceramics material produced by the method of any one of claims 1 to 3.

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