JPS63291881A - Porous ceramic material and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled material having excellent appearance, frost damage resistance and coloring properties, by press molding a surface layer raw material consisting of frit, etc., a binder, a ceramic material and water and a base layer raw material consisting of frit, etc., a binder, a ground material such as tile and water and then burning. CONSTITUTION:A raw material for a surface layer 12 obtained by blending a natural raw material such as porcelain chamotte, silica sand and feldspar with ceramic material particles such as ground cullet of high-melting glass, glassy material such as frit, a binder made of paste and water and a raw material for a base layer 14 obtained by blending ground particles such as tile with the binder and water are press molded to form a molded material of double structure. Then the material is removed from a mold, dried and burnt at a temperature <=melting temperature of the ground ceramic material particles and tile and a temperature >=melting temperature of the glassy material to form a porous ceramic material consisting of the surface layer 12 wherein surface layer particles 11 having <=2.5mm particle diameters obtained by coating the whole surface of the ceramic material with the glassy material 15 are bonded and the base layer 14 wherein base layer particles 13 having <=10mm particle diameters obtained by coating the whole surface of the ground particles of the tile with the glassy material 15 are bonded. The particles in both the layers have average particle diameters >=3/70 thickness of each layer.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to porous ceramic materials used for road paving, Efsteria flooring, flooring around indoor and outdoor swimming pools, indoor and outdoor sound absorbing materials, interior and exterior materials, etc. and its manufacturing method,
The objective is to achieve excellent frost damage resistance by dramatically improving water permeability compared to conventional materials. Generally, the materials used for road paving etc. are made water permeable by:
The purpose is to control rainwater runoff, recharge groundwater, grow plants, etc.

[Conventional technology]

BACKGROUND ART Conventionally, as a technique related to porous ceramic materials used for roads, parking lots, park grounds, etc., there is a technique described in, for example, Japanese Patent Laid-Open No. 61-36157. In this prior art, as shown in FIG. 3, non-water retaining particles 1 with a water absorption rate of less than 4% and water retaining particles 2 with a water absorption rate of 5% or more are combined with a binder 3, and each particle 1 and A continuous pore 4 is formed between the two. The continuous pores 4 allow the product tile 5 to have water permeability. Thus, the surface of each particle 1 and 2 is exposed to the continuous pores 4 except for the bonded portion by the binder 3. Therefore, a portion of the rainwater etc. that has permeated through the continuous pores 4 is absorbed by each water-retaining particle 2, and excess rainwater etc. passes through the product and is discharged to the outside. In other words, in this prior art, the product tile 5 has both water permeability and water retention properties. The reason for providing water retention in addition to water permeability is that if the product tile 5 is exposed to strong sunlight, it will dry quickly and the surface will reach a high temperature of 40 to 50 degrees Celsius, deteriorating the living environment. This is to reduce the surface temperature of the product tile 5 using the heat of vaporization.

In addition, in this conventional example, as shown in FIG. A product tile 8 having a two-layer structure with a single layer as the surface layer 7 is disclosed.

[Problem that the invention seeks to solve]

However, in the conventional technology described in Japanese Patent Application Laid-Open No. 61-36157 mentioned above, since product tiles 5 and 8 have water-retaining properties, when used in cold regions etc., the water-retaining particles 2 had the disadvantage that rainwater, etc. stored in the system would freeze, causing cracks and damage. in short,
The conventional product tiles 5 and 8 had the problem of lacking frost resistance and could not be used in cold regions or environments where there is a risk of freezing. Moreover, in the product tile 5 shown in FIG. 3, since the purpose is to make the water-retaining particles 2 absorb rainwater and have water-retaining properties, the particle size of the water-retaining particles 2 is increased to retain water. It is necessary to increase the surface area of the entire surface of the particles, which has the disadvantage that the surface quality of the product tile 5 deteriorates, resulting in poor appearance. This means non-water retaining particles! Even in the case of product tile 8 with a single layer of water on the surface [7], there was a similar problem in appearance because the particle sizes of non-water retaining particles 1 and water retaining particles 2 were approximately the same. .

[Means for solving problems]

The present invention has been developed to improve and eliminate the above-mentioned conventional problems, and to achieve a dramatic improvement in water permeability without imparting water retention properties, the present invention is a porous ceramic material with excellent frost damage resistance. and its manufacturing method.

Therefore, the technical means for producing porous ceramic material adopted by the present invention in order to solve the above-mentioned problems is to cover the entire surface of each particle of the ceramic material with a glassy material such as frit, and bond each particle to each other. and a base layer in which each particle of a pulverized product such as a roof tile whose particle size is coarser than that of the ceramic material particle is entirely covered with a glassy material such as frit, and each particle is bonded to each other. Continuous pores are formed between each particle of the surface layer and the base layer, and the average particle size of each particle of the surface layer and the base layer is 3/70 or more of the thickness of each layer.

Other technical means for producing porous ceramic materials include a surface layer in which each particle of the porcelain material is bonded with a glassy material such as a frit, and a pulverized material such as a roof tile whose particle size is coarser than that of the particles of the porcelain material. It consists of a base layer in which each particle of the object is entirely covered with a glassy material such as a frit, and each particle is bonded to each other, and continuous pores are formed between each particle of the surface layer and the base layer. The average particle size of each particle in the layer and the base layer is 3/70 or more of the thickness of each layer.

Furthermore, the method for producing the porous ceramic material includes a surface layer raw material that is a mixture of a glassy material such as a frit, a binder mainly composed of glue, a ceramic material, and water, a glassy material such as a frit, and a glue. A two-layer structure is formed by pressure molding a binder mainly composed of a binder, a crushed material such as a roof tile, and a base layer raw material mixed with water, and after demolding and drying, the molded base is molded into the above-mentioned ceramic material. By firing at a temperature lower than the melting temperature of the pulverized materials such as tiles and tiles and higher than the melting temperature of the glassy material such as the frit, the entire surface or part of each particle of the surface layer and each particle of the base layer are heated. The entire surface is coated with a glassy material, and the particles of the ceramic material and the crushed material such as roof tiles are bonded together to form continuous pores between the particles.

(Function) As is clear from the embodiments shown in FIGS. 1 and 2, the surface layer 12 is formed with particles 11 of ceramic material by pressure molding, and the base layer W 114 is formed with particles 13 of crushed material such as roof tiles. After pressure molding, the particles are fired at a temperature lower than the melting temperature of the particles 11 and 13 and higher than the melting temperature of the glassy material 15, which is one of the main components of the binder. The entire surface of particles 11 and 13 can be covered with glassy material 15 to bond each particle 11 and 13 to each other. Moreover, continuous pores 16 and 17 are formed between each particle 11 and 13, respectively. It is formed.

In the porous ceramic material 10 obtained in this way, each particle 11 is relative to the thickness of the surface layer 12 and base layer 14.
And by selecting the average particle size of 13 to be 3/70 or more,
Rainwater and the like are easily discharged to the outside through the continuous pores 16 and 17, thereby achieving a dramatic improvement in water permeability. Further, since the entire surface of the particles 11 and 13 is coated with the glassy material 15, each particle 11
And 13 does not absorb rainwater or the like passing through continuous pores 16 and 17. Therefore, even if the porous ceramic material 10 is used as a paving material in a cold region, the material 10 will not crack or break due to freezing. It is possible to provide a quality ceramic material 10.

〔Example〕

EMBODIMENT OF THE INVENTION The porous ceramic material of this invention and its manufacturing method are demonstrated below based on the Example shown in drawing.

FIG. 1 shows a porous ceramic material 10 according to an embodiment of the present invention.
FIG. 2 is a partially enlarged view of FIG. 1.

As shown in the figure, the porous ceramic material 10 is made of so-called ceramic or porcelain materials such as natural raw materials such as porcelain chamotte, silica sand, and feldspar, high melting point glass cullet, and crushed materials such as roof tiles, clay pipes, and bricks. It consists of a surface layer 12 in which particles 11 of (hereinafter referred to as ceramic material) are bound together with a binder, and a base layer 14 in which particles 13 of crushed materials such as roof tiles, clay pipes, and bricks are bound together with a binder. It has a two-layer structure.

The binder is mainly made of a vitreous material such as frit or glass, and glue, and cement is added as needed. The reason for using a glassy material is that the surface layer 1
This is to bond the particles 11.13 of the particles 11.13 of the bonded particles 11.13 and to form continuous pores 16.17 between the particles 11.13 in the bonded state. The reason for using the glue is to impart shape retention to the molded base material after pressure molding the raw material particles. The reason why cement is added as necessary is to give the dried molded material before firing a strength sufficient to prevent it from losing its shape.

By the way, the reason why the porous ceramic material 10 has a two-layer structure is to improve water permeability and provide frost damage resistance, and to improve the surface quality and improve the external appearance. In other words, this is because, in addition to the direct objective of the present invention, which is to obtain this type of porous ceramic material with excellent frost damage resistance, the design aspect was taken into consideration. This kind of material used for road paving in cold regions etc. must have frost damage resistance. Moreover, since it is used for road paving, it is necessary to have good surface properties such as color and surface roughness, and it is preferable that the particle size of the material particles 11 of the surface layer I2 is as small as possible.

In order to satisfy such requirements, it is necessary to consider the mutual relationship between the particle size of the material particles 11 used for the surface layer 12 and the thickness of the surface layer 12. It is necessary to consider the correlation between the particle size of the material particles 13 and the thickness of the base layer 14. The reason is that each particle 11
Even if the size of the pores 16 and 17 formed between the particles 11 and 13 is increased to some extent to improve water permeability, the particle size of each layer 12 is increased.
If the thickness of 14 becomes too thick, the time for rainwater etc. that has entered the porous ceramic material 10 to pass becomes extremely long (water is retained in the material 10), and as a result, the water permeability as a whole decreases. This is because there is a risk of frost damage.

The present inventors conducted various experiments in view of the above-mentioned points, and found that in both the surface layer 12 and the base Jiif 14, there is a difference between the particle size of each particle and the thickness of each layer. It has been found that the desired frost damage resistance cannot be obtained unless the average particle size of each particle is 3/70 or more of the thickness. However, the relationship between the average particle diameter of each particle and the thickness of each layer does not mean that the value can be infinitely increased as long as it is 3/70 or more.
The particle size of the particles 11 of fj12 is, as mentioned above, unsightly from a design point of view if it is coarse, so the maximum particle size is 2.
The particle size of the particles 13 of the base layer 14 is preferably 5fi or less, and if the particle size of the particles 13 of the base layer 14 is too large, pressure molding becomes difficult and the bonding strength between particles becomes weak. is preferred. The optimal relationship between the particle size of each particle and the thickness of each layer is, for example, when the overall thickness of the porous ceramic material 10 is 4 On and the thickness of the surface layer 12 is 5 days, the particles 11 of the surface layer 12 are The diameter is 0.3
An average particle size of 0.75n is appropriate in the range of ~1.2■,
The particle size of the particles 13 of the base layer 14 is in the range of 1 to 4 grains, and an average particle size of 2.5n+m is appropriate.

What is important about the porous ceramic material 10 according to the present invention is that its water permeability is dramatically improved in order to have excellent frost damage resistance. This is based on the thickness of each particle 11 and 1 for each layer 12 and 14 described above.
This is due to the limited relationship between the particles 11 and 13 and the bonding structure between the particles 11 and 13, which will be described next. As shown in FIGS. 1 and 2, the bonding structure of each particle is as follows: Each particle 1 is coated and bonded with a glassy material 15 such as frit glass, which is one of the main components of the binder.
Continuous pores 16 and 17 are formed between 1 and 13 spaces. By covering the entire surface of each particle 11 and 13 with a glassy material, each particle 11 and 13 individually stops absorbing water. Therefore, rainwater etc. that have entered the porous ceramic material 10 pass through the pores 16 and 17 to the outside due to the effect of limiting the relationship between the particle size and the eyebrow thickness described above. and will not remain inside the material 10. Therefore, it is possible to achieve a dramatic improvement in water permeability,
Even if this porous ceramic material IO is used as a road paving material in cold regions where there is a risk of frost damage, frost damage will not occur. When a porcelain material with low water absorption (water absorption rate of 1% or less) is used as the material itself, it is not necessarily necessary to cover the entire surface of the particle 11 with the glassy material 15. In this case, the glassy material 15 It is only necessary to bond the particles 11 at the contact portions with each other, and the amount used can be reduced.

By the way, when the entire surface of each particle 11 and 13 of the surface layer 12 and base layer 14 is coated with the glassy material 15 as in the embodiment shown in FIGS. 1 and 2, the blending ratio of each of these materials is is important. When the ratio of the glassy material 15 to each ratio of the materials of the surface layer 12 and the base layer 14 is small, each particle 1 of both layers 12 and 14
This is because the entire surface of the tiles 1.13 cannot be covered with the glassy material 15. In other words, each particle 13 of crushed materials such as roof tiles, clay pipes, and bricks will not absorb rainwater that has penetrated into the tiles. This is because, in cold regions, the absorbed moisture freezes and causes cracks and damage, making it impossible to achieve the object of the present invention.

Furthermore, if the proportion of the glassy material 15 is small, the bonding strength between the particles 11, 13 of the surface layer 12 and the base layer 14 will be weakened, and there is a risk that the desired strength of the porous ceramic material 10 as a whole may not be obtained. Because there is. On the other hand, if the glassy material 15 accounts for a large proportion, continuous pores 16.1 formed between each particle 11.13 after firing.
7 is blocked by the vitreous material 15 and loses water permeability, making it impossible to achieve the original purpose of this type of porous ceramic material.

From these facts, the proportion of the vitreous material 15 is:
The following range is appropriate. That is, for the surface layer 12, 20 to 50 wt% is appropriate for the ceramic material, and for the base 1ii14, 20 to 50 mt% is appropriate for the crushed material such as roof tiles, clay pipes, and bricks. . This is clear from the results of actually manufacturing the porous ceramic material 10 by changing the blending ratio of the glassy material 15 and observing it with a microscope and with the naked eye.

That is, according to the observation results, when the blending ratio of the glassy material 15 is below the lower limit value, the entire surface of each particle 11.13 cannot be covered with the glassy material 15 in any case, and the upper limit When the value exceeded the value, pores 15 and 16 could not be formed.

Next, a method for manufacturing the porous ceramic material 10 will be explained.

First, a raw material for the surface layer 12, which is a mixture of a ceramic material, a binder, and water, is filled into a mold, and a preload is applied to temporarily tighten the surface layer 12. After that, tiles and clay pipes.

Base layer 14 made of a mixture of crushed materials such as bricks, binder, and water
The raw materials are filled onto the temporarily tightened surface layer 12 in the mold, and pressure molded while applying vibration.

The reason for applying vibration is to uniformly disperse the mixed raw materials,
This is to prevent variations in the packing density and to improve the packing density. Note that the order of pressure molding may be reversed to the above case, such that the base layer 14 is first filled and temporarily tightened, and then the surface layer 12 is molded.

Next, the pressure-molded two-layer structure is demolded.

In the molding base immediately after this molding, the cement as a binder added as necessary has not yet sufficiently hydrated and hardened, and the glassy material does not play a role in binding the raw material particles. , the shape retention of the molded base immediately after molding is,
It is done with glue as a binder. After that, the molded base is dried. During the period from the drying process to the firing process, cement gradually develops strength due to hydration hardening, and shape retention increases.

Then, if necessary, the surface 12a of the surface [12] is colored or patterned, and finally the molded base having the two-layer structure is fired. In addition, the above-mentioned coloring or patterning is based on Jii.
It goes without saying that a pigment or the like that develops color upon firing may be mixed into the 12 raw materials. Firing is performed on the surface [12
900 to 900, which is lower than the temperature at which the ceramic material particles 11 and the crushed particles 13 of the base layer 14, such as tiles, melt, and higher than the temperature at which the vitreous material 15 as a binder melts.
This calcination, carried out at a calcination temperature in the range of 1350°C, results in
The glue disappears.

As shown in an enlarged view in FIG. 2, the particles 11 and 13 are entirely covered with the molten glass material 15 and bonded to each other. Furthermore, in this bonded state, continuous pores (voids) 16.17 are formed between each particle 11.13. Therefore, firing here is different from sintering, which is generally used in the ceramic industry to melt and bond tile material particles, and is rather close to the concept of simple bonding.

As a result, it is possible to obtain the porous ceramic material 10 having a two-layer structure shown in FIGS.
1.13 (it passes through the continuous pores 16 and 17 between each particle 11 and 13 and is discharged to the outside). In other words, this porous ceramic material 10 retains moisture inside it. Therefore, even if it is used for road paving in environments where there is a risk of frost damage, such as in cold regions, there will be no problem of frost damage.Moreover, the surface layer 12
The size of the continuous pores 16 in the base layer 14 is smaller than the size of the continuous pores 170 in the surface layer 12 to the material 10.
All of the rainwater that has entered the interior easily passes through the base layer 14. By utilizing this property, it is easy to suppress the amount of water that passes through the interior of the material 10 from the paved road surface to the geological layer.

Next, a case where the porous ceramic material 10 included in the present invention is manufactured based on specific raw materials and blending ratios, and a case where a porous ceramic material that exceeds the relationship between particle size and layer thickness of the present invention is manufactured. The following explains the correctness of limiting the lower limit of the relationship between grain size and layer thickness. Note that the upper limit value is already clear from the above-mentioned experimental results, so a description thereof will be omitted here.

(Comparative Example 1) First, 75 parts by weight of a porcelain chamotte with a water absorption rate of 0.5% and a particle size ranging from 0.3 to 1.2 mm and an average particle size of 0.75 m, and 25 parts by weight of a binder, A mixed material containing 12 parts by weight of an aqueous solution of 10 to 15% dextrin is prepared as a raw material for the surface layer 12. In this case, the binder has 22 frits.
．． 5 parts by weight, cement is 2.5 parts by weight, and the ratio of frit to the entire binder is 90-t%.
It is. In addition, the ratio of frit to porcelain chamotte is 15 wt%, which is 75% by weight of crushed roof tiles with a water absorption rate of 4 to 8 wt%, a particle size in the range of 1 to 4 pieces, and an average particle size of 2.5 tons. parts, binder - 25 parts by weight, 10 to 15 parts
A mixed material containing 15 parts by weight of dextrin aqueous solution was added to the base layer 14.
Prepare as raw material. In this case, the binder contains 22.5 parts by weight of frit and 2.5 parts by weight of cement, and the ratio of frit to the entire binder is:
90-t%.

Further, the ratio of the frit to the crushed tile material is 30-t%.

Thereafter, the tile-forming base was pressure-molded in accordance with the manufacturing method described above, and then fired at a temperature of 1100°C. As a result, for each particle 11 of the surface layer 12, the vitreous material acts only as a binder, and the entire surface of the particle 11 of the porous ceramic material 10 shown in the embodiment of FIGS. 1 and 2 is A product with a two-layer structure was obtained in which each particle 13 of the base layer 14 was not covered with a glassy material but was entirely covered with a glassy material 15. In this case, the size of the product is! 11297w x width 297cm x thickness 40mm,
The thickness of the surface layer 12 was 5cm.0 The relationship between the average particle diameter of the particles 11 and 13 in the surface layer 12 and the base layer 14 and the layer thickness was 3720 in the case of the surface 1'1iif12; The case is 1/14, and in both cases it is 3770 or more, which is within the scope of the present invention. Therefore, the hydraulic conductivity of the product obtained in this way is 5X10-2 (2
)/S, and the bending strength was 80 Kg/cm. In addition, in a confirmation test to confirm frost damage resistance, it was able to withstand 300 repeated tests, demonstrating excellent frost damage resistance.

In addition, in the confirmation test for freeze damage resistance, the specimen is immersed in clean water at room temperature for 24 hours, then immediately placed in the test tank, and
After being left in an atmosphere at ±3°C for 80 minutes, it was taken out and 30°C hot water was sprinkled on it for 20 minutes to melt it, and this was considered one cycle, and the test was repeated.

For reference, the diameter of the continuous pores 16 obtained on the surface 1'1W12 of this product tile is 0.2 to 1. Otm, base layer 14
The diameter of the continuous pores 17 obtained in the above was 0.5 to 3.0 mm, and the porosity of the entire product tile was about 35%.

(Comparative Example 2) A raw material for surface FiW12 that differs from Comparative Example 1 only in the mixing ratio of frits was prepared, and the base J'! A raw material for Comparative Example 1, which differed only in particle size from that of Comparative Example 1, was prepared. In this case, the ratio of the frit to the porcelain material on the surface [12] is 30 wt%, and the base layer 14
The particle size ranges from 0.5 to 2.0 fl, with an average particle size of 1.25n.

Thereafter, the tile-forming base is pressure-formed in the same manner as described above, and then fired at a temperature of 1100°C to form the particles 11 of the surface layer 12 and the base layer 14 shown in FIGS. 1 and 2. A porous ceramic material having a two-layer structure in which the entire surface of each particle 13 was coated with a glassy material 15 was produced. The size of the porous ceramic material in this case was 15 fi thicker than in Comparative Example 1, and was 55 fi. The thickness of the base layer 14 in Comparative Example 2 is 50 m+, and the relationship between the particle size of the particles in the base layer 14 and the layer thickness is 1/40. That is, it is outside the scope of the present invention. The results of the frost damage test for this product, which is not included in the present invention, were that it could withstand only 10 repeated tests, and the desired frost damage resistance could not be achieved.

(Comparative Example 3) In Comparative Example 3, only the particle size of the particles of the base layer 14 in Comparative Example 2 was changed. The particle size of the particles is 1.0~
2. The average particle size is 1.5 cm in the Otm range. The relationship between the average particle size and the layer thickness in this case is 3/100, which is outside the scope of the present invention. In the case of the product of Comparative Example 3 as well, the test results for confirming frost damage resistance showed that it could withstand only 10 repeated tests, and the desired frost damage resistance could not be obtained.

(Comparative Example 4) In Comparative Example 4, only the particle size of the particles of the base layer 14 in Comparative Example 2 was changed, and the particle size of the 0 particles was 1.0 to 1.0.
The average particle size is 2.5 yen in the range of 4.0 yen. The relationship between the average particle diameter of the particles and the layer thickness is 1/20, which is included in the present invention. In the case of the product of Comparative Example 4, it was able to withstand 300 repeated tests to confirm frost damage resistance. In other words, the desired frost damage resistance could be achieved.

What is clear from these Comparative Examples 1 to 4 is that the surface Fi
12 and group r514, when the relationship between the average particle size of the particles in each layer and the layer thickness is 3/70 or more, a porous ceramic material 10 with excellent frost damage resistance can be obtained. Furthermore, when each particle 11 of the surface layer 12 is made of a porcelain material, the entire surface of each particle 11 does not necessarily have to be covered with a glassy material.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to provide a porous ceramic material with excellent frost damage resistance. Furthermore, since the surface roughness of the surface layer is extremely fine, it has a good appearance and is easy to color and pattern, giving it great product value. Furthermore, since pulverized materials such as roof tiles, clay pipes, and bricks can be used as raw materials, raw materials can be obtained at low cost, and product prices can be significantly reduced.

[Brief explanation of drawings]

Figures 1 and 2 are according to the present invention; Figure 1 is a partial vertical cross-sectional view of a porous ceramic material, Figure 2 is a partially enlarged view of Figure 3, and Figure 3 is a conventional porous ceramic material. FIG. 4 is a partially enlarged longitudinal sectional view of a porous ceramic material showing another conventional example. 12...Surface layer 14...Base layer 11...
Particles in the surface layer I3... Particles in the base layer 15... Glassy material 16.17... Continuous pores Patent applicant Inax Co., Ltd. Agent Kasai Glaze Industry Co., Ltd.
Patent Attorney Toshihiko Uchida J Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A surface layer in which each particle of a ceramic material is entirely covered with a glassy material such as a frit and the particles are bonded together, and a tile whose particle size is coarser than that of the particles of the ceramic material. It consists of a base layer in which each particle of the pulverized product is completely covered with a glassy material such as a frit, and each particle is bonded to each other, and continuous pores are formed between each particle of the surface layer and the base layer. . A porous ceramic material, wherein the average particle diameter of each particle in the surface layer and the base layer is 3/70 or more of the thickness of each layer. 2. A surface layer in which each particle of a porcelain material is bonded with a glassy material such as a frit, and each particle of a crushed material such as a roof tile, which has a coarser particle size than the particles of the porcelain material, is bonded with a glassy material such as a frit. It consists of a base layer that is entirely covered with a material and that binds each particle, continuous pores are formed between each particle of the surface layer and base layer, and the average particle size of each particle of the surface layer and base layer is is a porous ceramic material characterized in that the thickness of each layer is 3/70 or more. 3. Grinding of glassy materials such as frits, binders mainly composed of glue, ceramic materials, and surface layer raw materials mixed with water, glassy materials such as frits, binders mainly composed of glues, roof tiles, etc. A two-layer structure is formed by pressure-molding the base material mixed with the ceramic material and water. By firing at a temperature lower than the melting temperature of the glassy material such as the frit, the entire surface or part of each particle of the surface layer and the entire surface of each particle of the base layer are coated with the glassy material, and the ceramic is heated. 1. A method for producing a porous ceramic material, characterized in that particles of a ground material and a pulverized material such as a roof tile are bonded to each other, and continuous pores are formed between these particles.