KR101731139B1 - Porous ceramic tile having high strength and high moisture-absorbing - Google Patents

Abstract

15 to 60% by weight of gamma -alumina and 5 to 20% by weight of a glassy bonding material.

Description

TECHNICAL FIELD [0001] The present invention relates to a porous ceramic tile having high strength and high moisture resistance,

To a porous ceramic tile having high strength and high moisture absorptive and desorptive properties.

In recent years, the quality of indoor air has been inevitably deteriorated unless indoor air is forcibly ventilated with outside air due to super high-rise building, high thermal insulation and meat dense building. Particularly, due to high indoor humidity in the summer, condensation occurs in the living room window or in the corners of the room, resulting in mold, mites and the like, causing problems such as respiratory diseases and atopy.

In order to solve this problem, it is necessary to develop a building material for interior finishing which has a humidity control function to absorb humidity when the humidity is high and to lower the room humidity and then to increase the humidity by discharging the absorbed moisture when dried.

In order to maximize the humidity control function, it is necessary to be able to support as much as possible the core materials such as zeolite and diatomaceous earth which exhibit the humidity control function. In general, the tiles having the thickest thickness among the indoor finishes are ideal.

However, until now, the products which are launched as functional tiles in Korea have a disadvantage that they have moisture absorption function and moisture proof function but their physical properties such as strength of tiles are inferior. Most of them are made by design in preference to functionality, It is necessary to develop a technique for a ceramic formed body that exhibits strength and physical properties.

One embodiment of the present invention provides a porous ceramic tile including a glassy bonding material that increases strength by acting as a γ-alumina and binder excellent in moisture absorption and moisture-proofing functions.

In one embodiment of the present invention, there is provided a porous ceramic tile comprising about 15% to about 60% by weight of gamma -alumina and about 5% to about 20% by weight of a glassy bonding material.

Wherein said gamma -alumina is a material in which one aluminum source selected from the group consisting of aluminum nitride, aluminum carbonate, aluminum chloride, aluminum chloride dihydrate, aluminum hydroxide, aluminum chloride, aluminum nitride, alumina sol, . ≪ / RTI >

The glassy bonding material may include glass frit.

The porous ceramic tile may comprise from about 25% to about 65% by weight of the parent material in a total of 100% by weight.

The parent material may include at least one selected from the group consisting of clay, clay, loess, and combinations thereof.

At least one additive selected from the group consisting of diatomaceous earth, feldspar, stones, lime, emulsifiers and combinations thereof.

The porous ceramic tile may comprise up to about 5% by weight of the additive for a total of 100% by weight.

The bending strength of the porous ceramic tile may be from about 10 MPa to about 20 MPa.

The moisture absorptive and desorptive amount of the porous ceramic tile may be about 60 g / m ² to about 100 g / m ² .

The porous ceramic tile may include porous ceramic tile-forming particles connected by the glassy bonding material.

The porosity of the porous ceramic tile-forming particles may be from about 30% to about 50%.

The porous ceramic tile may include pores having an average diameter of about 0.5 [mu] m to about 50 [mu] m.

The porous ceramic tile can be used as a functional tile by maintaining and enhancing the moisture absorptive and desorptive properties while enhancing the low plasticity strength.

1 is a schematic view of a porous ceramic tile according to an embodiment of the present invention.
2 is a schematic representation of a conventional porous ceramic tile.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In one embodiment of the present invention, there is provided a porous ceramic tile comprising 15% to 60% by weight of gamma -alumina and 5% to 20% by weight of a glassy bonding material.

Conventional porous ceramic tiles need a firing process in production, and tiles can be classified according to the firing temperature range. A polishing tile formed by firing at a temperature of about 1300 deg. C or higher, a magnetic tile formed by firing at a temperature of less than about 1300 deg. C, and a ceramic tile formed by firing at a temperature of about 800 deg. C, It is general that the recorded structure is dense and has high bending strength.

In the conventional porous ceramic tile, the sintering process was performed at a temperature of about 1000 ° C. or below to make open pores for smooth entry / exit of air, so that the structure is not denser than general magnetic and polishing tiles, There was a weak problem.

In order to compensate for this, a certain amount of glassy material capable of acting as a binder is added. However, as the content of the vitreous material is increased, the pores of the air are blocked, and the micro pores of the core material exhibiting the humidity control function are blocked, .

In the present invention, in order to improve the bending strength of the humidity control tile without deteriorating the moisture absorptive and desorptive properties, the content ratio of the glassy bonding material serving as a binder and the gamma -alumina functioning as a humidity control is controlled in the porous ceramic tile composition, The ceramic tile may comprise about 15% to about 60% by weight of gamma -alumina and about 5% to about 20% by weight of the glassy bonding material.

The γ-alumina is a transition alumina and can impart a humidity control function. It is a material that can exhibit excellent properties as a separation membrane, a catalyst, a catalyst carrier and an adsorbent because it has a wide specific surface area and fine pore holes and can be changed into another structure by heat treatment of an aluminum source.

The γ-alumina may be formed on the surface of the pores included in the porous ceramic tile-forming particles to have an excellent humidity control and deodorizing function. Accordingly, when the humidity is high, the γ-alumina absorbs moisture through the pores to lower the humidity of the room. On the contrary, when the humidity is low, the γ-alumina emits moisture stored in the pores to increase room humidity do. The γ-alumina may be a commercially available γ-alumina, but in view of cost reduction and efficiency, specifically, γ-alumina which is phase-shifted by heat treatment at a low cost aluminum source can be used.

The gamma -alumina may comprise from about 15 wt% to about 60 wt%, specifically from about 10 wt% to about 35 wt%. When the content of the? -Alumina is less than about 15% by weight, it may become difficult to exhibit a sufficient humidity control function. When the content exceeds about 60% by weight, have.

Therefore, by including γ-alumina in the above range, it is possible to exhibit a high humidity-conditioning function and secure the strength of a stable tile.

The specific surface area of the? -Alumina is not particularly limited, but may be, for example, from about 150 m 2 / g to about 350 m 2 / g. When the specific surface area of the? -Alumina is less than about 150 m 2 / g, it can not exhibit a sufficient humidifying function. When the specific surface area exceeds about 350 m 2 / g, the manufacturing process may become difficult, have.

Specifically, the? -Alumina may be a single aluminum source selected from the group consisting of aluminum nitride, aluminum carbonate, aluminum chloride, aluminum chloride dihydrate, aluminum hydroxide, aluminum chloride, aluminum nitride, alumina sol, Or < / RTI > However, the alumina source is not limited to the exemplified ones, and all the aluminum sources that can be phase-changed to gamma -alumina by heat treatment may be included in the aluminum source.

For example, when the aluminum hydroxide (Al (OH) ₃ ) is phase-changed to gamma -alumina (Al2O3), the gamma -alumina conversion of the aluminum hydroxide may be from about 0.6 to about 0.7.

The porous ceramic tile may comprise a glassy bound material. The glassy bonding material refers to a vitreous substance containing about 75% or more of glass. The glassy substance means an amorphous solid state without crystallization when rapidly cooled in a molten state, and having no long-range regularity in the arrangement of atoms.

Specifically, the glassy bonding material may comprise from about 5% to about 20% by weight. When the glassy bonding material is less than about 5% by weight, there is a fear that the plasticity is weakened. When the glassy bonding material is more than about 20% by weight, the manufacturing cost is increased. Therefore, by including the glassy bonding material in the above content range, it is possible to easily realize the effect of exhibiting the plasticity strength with respect to the production cost.

The glassy bonding material may include glass frit. The glass frit starts to melt at a temperature of about 700 ° C. which is lower than the firing temperature of a general tile as a low melting point glass, facilitates the movement between the particles during the firing process of tiles, and increases the strength of the porous ceramic tile It plays a role.

Due to the role of the binder, the glass frit acts as a binder to reduce pores as air inlet and outlet passages between the porous ceramic tile-forming particles and to block the pores exhibiting moisture absorptive and desorptive property on the surface of the porous ceramic tile- can do. However, by controlling the content of the glassy bonding material, the porosity between the porous ceramic tile-forming particles is reduced by the glassy bonding material, and the phenomenon of the decrease in the moisture absorptive and desorptive property caused by clogging of the pores on the surface of the porous ceramic tile- .

The porous ceramic tile may include a mother material other than the? -Alumina and the glassy bound material. The parent material is a material that serves as a base material for forming the porous ceramic tile, that is, a material acting as a skeleton in the tile. Specifically, the parent material is at least one selected from the group consisting of clay, clay, . ≪ / RTI >

The content of the parent material is not particularly limited and may be varied depending on the application field and application of the porous ceramic tile. For example, the content of the parent material may be about 100 wt% From about 25% to about 65% by weight. By including the parent material in the above range, the porous ceramic tile can be appropriately shaped and sintered, and mechanical stability can be ensured.

The porous ceramic tile may further include at least one additive selected from the group consisting of diatomaceous earth, feldspar, stones, lime, a whitening agent, and combinations thereof. The content of the additive is not particularly limited, and can be suitably adopted within a range in which the function of the porous ceramic tile is not impaired.

Specifically, the porous ceramic tile may comprise up to about 5% by weight, specifically up to about 3% by weight, of the additive, based on 100% by weight of the total. By including the additive of the above content, it is possible to appropriately adjust the content of? -Alumina, the glassy bonding material and the parent material, so that the physical stability such as the molding strength and the plasticity strength of the porous ceramic tile and the function of the moisture- have.

The diatomaceous earth among the additives is an absorbent porous material, and when added to the porous ceramic tile formation, the moisture absorption function can be further improved, and other quartz, feldspar, stones and lime can also be contained in appropriate amounts. In addition, the above-mentioned whitening agent is a powder to be added to a glass product in order to give a whiteness. The kind of the whitening agent is not particularly limited, but is preferably at least one selected from the group consisting of chloride, tin, titanium oxide, sulfate, phosphate, . ≪ / RTI >

The bending strength of the porous ceramic tile may be from about 10 MPa to about 20 MPa. The bending strength refers to the maximum tensile stress at fracture in the bending test, which means the maximum tensile stress at the time of fracture of the porous ceramic tile when the bending pressure is applied to the porous ceramic tile. The bending strength of a conventional porous ceramic tile is measured to have a bending strength of less than about 10 MPa, but the porous ceramic tile contains from about 5 wt% to about 20 wt% of the glassy bonding material serving as a binder, It is possible to secure a bending strength improved by about 100% or more as compared with the bending strength of the tile.

The bending strength of ordinary ceramic tiles other than porous ceramics is about 20 MPa. In this case, breakage during transportation and construction is extremely rare, so it is usually used as a criterion of appropriate strength. Therefore, the bending strength of the porous ceramic tile is similar to the bending strength of a general ceramic tile, so that it is possible to minimize breakage and crack production due to physical impact occurring during production of porous ceramic tiles, transportation and construction, So that the production cost can be reduced and the construction speed can be improved.

The moisture absorptive and desorptive amount of the porous ceramic tile may be about 60 g / m ² to about 100 g / m ² . The moisture absorptive and desorptive amount of the porous ceramic tile is required to control the humidity in a humid region (temperature of about 25 ° C, relative humidity of about 50% to about 75%) in which humans can live the most comfortable life, Can be calculated as the average of the amount of moisture and the amount of moisture. By maintaining the moisture absorbing and desorizing amount of the tile within the above range, the discomfort index due to moisture can be minimized, and the occurrence of fungi and bacteria in the tile can be suppressed.

In addition, the porous ceramic tile includes about 15 wt% to about 60 wt% of [gamma] -alumina, and may include pores having a porosity of a certain level or higher on the surface of the porous ceramic tile-forming particles. In addition, although the content of the glassy bonding material is included, the content of the glassy bonding material is controlled at the same time as the content of the γ-alumina is controlled, and the content of the glassy bonding material is controlled. Pore can be secured.

1 is a schematic view of a porous ceramic tile according to an embodiment of the present invention. The porous ceramic tile may include porous ceramic tile-forming particles connected by the glassy bonding material.

Specifically, the porous ceramic tile-forming particles may be connected by a glassy bonding material, and may include fine pores on the surfaces of the porous ceramic tile-forming particles and open pores between the porous ceramic-tile-forming particles. In addition, the porous ceramic tile-forming particles may include micropores clogged by a glassy material at the same time as the micropores, and the content of each material may be controlled to optimize the bending strength and the moisture absorptive and desorptive property.

The porous ceramic tile includes the content of the? -Alumina and the glassy bonding material forming the porous ceramic tile by controlling the content of the glassy bonding material as compared with the conventional porous ceramic tile shown in FIG. 2, The strength can be secured higher than that of the conventional porous ceramic tile.

The porosity of the porous ceramic tile-forming particles may be from about 30% to about 50%. Specifically, it means the porosity of the open pores formed between the micropores and the porous ceramic tile-forming particles distributed on the surface of the porous ceramic tile-forming particles. The porosity is a numerical value indicating the degree of the pores of the micropores and the open pores, The porosity means the percentage of open pores and micro pore volumes inside the tile relative to the total volume of the porous tile forming particles.

The porous ceramic tile includes a glassy bonding material in addition to the? -Alumina, and micropores clogged by the glassy bonding material may be generated. However, by controlling the content of the? -Alumina and the glassy bonding material, So that it is possible to easily realize an excellent humidity control effect due to a high humidity control function.

The porous ceramic tile may include pores having an average diameter of about 0.5 [mu] m to about 50 [mu] m. Specifically, the upper pore is a pore formed between the porous ceramic tile-forming particles, which is also referred to as an open pore, and means a space for facilitating the inflow and outflow of air. More specifically, the average diameter of the pores refers to the arithmetic average of the open pore diameters.

Since the porous ceramic tile serves as a binder or an adhesive by including a vitreous bonding material, the porous ceramic tile has an average diameter of the opened pores relatively smaller than that of the conventional porous ceramic tile, but the content of the glassy bonding material And the average diameter of the open pores within the above range can be maintained. As a result, a smooth flow of air and moisture can be ensured, and the strength of the tile can be maintained high. As a result, The relative amount of alumina is kept constant, and the humidity control function can be ensured.

Specifically, the porous ceramic tile may include pores having an average diameter of about 1 nm to about 50 nm. At this time, the pores may be fine particles distributed on the surface of the other porous ceramic tile-forming particles, and since the fine pores maintain the average diameter in the above range, the strength of the tile can be maintained high and the humidity control function can be secured.

Therefore, the porous ceramic tile includes both the glassy bonding material and the < RTI ID = 0.0 > y-alumina < / RTI > at the same time to secure the strength and moisture absorptive and desorptive properties of the porous ceramic tile.

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

< Example  And Comparative Example >

The mixture of solid components shown in Table 1 below was added to the total amount (%) of water by about 20 to 50%, and the resulting slurry was uniformly mixed through a ball mill and mixed by a spray drying process. The water content was 8% Spherical granules having a particle size of 300 mu m were prepared. At this time, the prepared granular powder contains the solid components listed in Table 2 below.

Subsequently, the granular powder was dry-pressed to produce porous ceramic tiles of 5 cm, 5 cm, and 0.6 cm in width, length, and thickness, respectively. Next, it was put into an electric furnace and fired at a temperature of 850 ° C. for 5 minutes to prepare a porous ceramic tile.

Specifically, the aluminum hydroxide (Al (OH) ₃ ) changes to γ-alumina (Al 2 O 3) and the calcite (CaCO 3) changes to calcium oxide (CaO) during the production process, 0.7, and the quicklime conversion rate of the pellets can be about 0.5 to about 0.6. In the following Tables 1 and 2, the conversion of gamma -alumina of aluminum hydroxide was 0.654 and the calcium oxide conversion rate was 0.56.

clay Aluminum hydroxide Glass frit burr Sancheong Calcite Pigment Sum Example 1 46.2 19.6 11 1.5 2.2 17.7 0.8 100 Example 2 39.6 29.3 11 1.3 1.9 15.2 0.7 100 Example 3 37.6 29.3 14 1.2 1.8 14.4 0.7 100 Example 4 31 39.1 14 One 1.5 11.9 0.5 100 Example 5 35.5 29.3 15.5 1.1 1.7 13.6 0.8 100 Example 6 28.9 39.1 15.5 0.9 1.4 11.1 0.6 100 Comparative Example 1 56 10 17.5 0.9 1.4 11.1 0.6 100 Comparative Example 2 16 70 5 0.9 1.4 11.1 0.6 100 Comparative Example 3 33 50 3 0.9 1.4 11.1 0.6 100 Comparative Example 4 41 20 25 0.9 1.4 11.1 0.6 100

clay γ-alumina Glass frit burr Sancheong quicklime Pigment Sum Example 1 54.7 15.2 13.0 1.8 2.6 11.7 0.9 100 Example 2 48.2 23.3 13.4 1.6 2.3 10.4 0.9 100 Example 3 45.6 23.2 17.0 1.5 2.2 9.8 0.8 100 Example 4 38.6 31.9 17.4 1.2 1.9 8.3 0.6 100 Example 5 43.6 23.5 19.0 1.4 2.1 9.4 1.0 100 Example 6 36.5 32.3 19.6 1.1 1.8 7.9 0.8 100 Comparative Example 1 62.8 7.3 19.6 1.0 1.6 7.0 0.7 100 Comparative Example 2 21.1 60.3 6.6 1.2 1.8 8.2 0.8 100 Comparative Example 3 42.4 42.0 3.9 1.2 1.8 8.0 0.8 100 Comparative Example 4 46.5 14.8 28.3 1.0 1.6 7.0 0.7 100

< Experimental Example > - Porous ceramic tile Absorption and desorption  And Flexural strength  Measure

The moisture absorptive and desorptive properties and flexural strength of the porous ceramic tiles of the examples and comparative examples were measured and the results are shown in Table 3 below.

1) Absorbing and desorbing amount: Porous ceramic tiles of the above examples and comparative examples were left for 24 hours under the conditions of a temperature of 25 ° C and a relative humidity (RH) of 50% , And the weight difference was measured. Then, the weight difference was measured again after holding for 12 hours at a temperature of 25 ° C and a RH of 50%, and the weight difference was measured.

2) Flexural strength: The three-point bending strength method was used to measure the flexural strength, and three rectangular parallelepiped tiles each having a length of 5 cm and a length of 5 cm and a height of 0.5 cm were prepared, and then a force was applied to the bending strength Were measured.

The bending strength is calculated by (3PL) / (2wt ^ 2), where P is the maximum load when the tile is broken, L is the external spacing, w is the width of the tile, and t is the thickness of the tile.

Moisture absorptive and desorptive amount (g / m ² ) Strength (MPa) Moisture absorptive and desorptive amount (g / m ² ) Strength (MPa) Example 1 70 10.8 Comparative Example 1 46 16.8 Example 2 86 11.1 Comparative Example 2 125 Destruction during sintering Example 3 83 13.8 Comparative Example 3 67 4.2 Example 4 109 10.6 Comparative Example 4 90 Destruction during sintering Example 5 71 16.4 Example 6 96 13.4

Referring to Tables 2 and 3, Examples 1 to 6 are porous tiles formed from 15 wt% to 60 wt% of gamma -alumina and 5 wt% to 20 wt% of glass frit, To 20 MPa, and the basis weight of the moisture absorptive and desorptive property was about 60 g / m ² or more. The porous ceramic tiles were simultaneously provided with flexural strength and moisture absorptive and desorptive properties according to the content of the vitreous bonding material and γ-alumina I can deduce that.

In contrast, the flexural strength of Comparative Example 1, which contained less than the content of y-alumina, was optimized, but the glass frit clogged the pores of the porous tile and did not secure moisture absorptive and desorptive properties. In Comparative Example 2, which contained much, the content of the parent material, that is, the clay, was lowered and the firing (molding) strength was reduced, and the fired ceramic tile was destroyed during firing.

In addition, in the case of Comparative Example 3 containing less the content of the glassy bonding material, the moisture absorptive and desorptive property was optimized due to the inclusion of gamma -alumina. However, the glassy bonding material had a weak strength due to the content of the low glassy bonding material, In case of Comparative Example 4, which contains more abundant materials, excessive shrinkage during sintering due to excessive glassy bonding material was destroyed by bending.

Claims (12)

15% to 60% by weight of gamma -alumina and 5% to 20% by weight of a glassy bonding material,
And a porous ceramic tile-forming particle connected by the glassy bonding material,
The micropores having an average diameter of 1 nm to 50 nm on the surface of the porous ceramic tile-
Wherein the porous ceramic tile-forming particles include open pores having an average diameter of 0.5 to 50 탆
Porous ceramic tiles.
The method according to claim 1,
Wherein said gamma -alumina is a material in which one aluminum source selected from the group consisting of aluminum nitride, aluminum carbonate, aluminum chloride, aluminum chloride dihydrate, aluminum hydroxide, aluminum chloride, aluminum nitride, alumina sol, Containing
Porous ceramic tiles.
The method according to claim 1,
Wherein the glassy bonding material comprises glass frit
Porous ceramic tiles.
The method according to claim 1,
Wherein the porous ceramic tile comprises 25 wt% to 65 wt% of parent material in a total of 100 wt%
Porous ceramic tiles.
5. The method of claim 4,
Wherein the parent material comprises at least one selected from the group consisting of clay, clay, loess and combinations thereof
Porous ceramic tiles.
The method according to claim 1,
Further comprising at least one additive selected from the group consisting of diatomaceous earth, feldspar, stones, lime, emulsifiers and combinations thereof
Porous ceramic tiles.
The method according to claim 6,
Wherein the porous ceramic tile comprises less than 5% by weight of the additive relative to a total of 100%
Porous ceramic tiles.
The method according to claim 1,
The bending strength of the porous ceramic tile is preferably 10 MPa to 20 MPa
Porous ceramic tiles.
The method according to claim 1,
When the moisture absorptive and desorptive amount of the porous ceramic tile is 60 g / m ² to 100 g / m ²
Porous ceramic tiles.
delete The method according to claim 1,
Wherein the porosity of the porous ceramic tile-forming particles is 30% to 50%
Porous ceramic tiles.
delete

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