JP2002154866A - Method for manufacturing ceramic product and ceramic product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing porous ceramics having excellent strength and high resistance against frost damages and to obtain the ceramics. SOLUTION: In the method for manufacturing ceramics, the source material of ceramics added with a glass/resin powder material is compacted and calcined at >=1,000 deg.C. Since the source material is calcined at >=1000 deg.C where the glass fuses by this method, the resin component in the glass/resin powder material burns in the calcining process to produce pores and then the glass component present in the pores fuses to coat the surfaces of the pores. The ceramics thus manufactured have higher strength than conventional porous ceramics because the surfaces of the pores are coated with the glass films. Moreover, because intrusion of water into the pores is suppressed by the glass films coating the surfaces of the pores, probability of cracks or fracture caused by freezing and expansion of the water is decreased and the resistance against frost damages is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a porous ceramic and a ceramic.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a porous ceramic, a method of adding a trace amount of a foaming agent to a ceramic raw material, or adding an organic substance, for example, resin particles to the ceramic raw material, and firing at a high temperature. To burn and extinguish the resin particles (JP-A-11-157914, etc.).

[0003]

However, the porcelain manufactured by the above-mentioned conventional method has a problem that the strength is reduced by the amount of the porous material. Further, in cold regions, etc., there is a risk that the water that has entered the voids freezes and expands, which may cause cracks or breaks in the porcelain, resulting in low frost damage resistance.

Accordingly, an object of the present invention is to provide a method of manufacturing a porous ceramic having excellent strength and high resistance to frost damage and a ceramic.

[0005]

A method of manufacturing a ceramic according to the present invention is characterized in that a glass resin powder is added to a ceramic raw material, molded and fired at a temperature of 1000 ° C. or more. Here, in this specification, the glass resin powder is
It refers to powdery and granular materials in which glass and resin are integrated.

In this method for producing ceramics, a glass resin powder is added to a ceramic raw material, and the glass resin powder is melted.
Since firing is performed at a temperature of 000 ° C. or more, the resin component in the glass resin powder is burned in the firing process to generate voids, and then the glass component present in the voids is melted and the surface of the voids is melted. cover. In the ceramics manufactured in this way, since the surface of the void is covered with the glass film, the strength is improved as compared with the conventional porous ceramics. In addition, since the intrusion of moisture into the voids is suppressed by the glass film covering the surface of the voids, the risk of cracking and cracking due to the freezing and expansion of the moisture is reduced, and the frost damage resistance is improved. You.

In the above-described method for manufacturing ceramics according to the present invention, one part by weight of the glass resin powder contains 100 parts by weight of the resin component.
It is preferable that 0 to 95 parts by weight and 5 to 90 parts by weight of a glass component are contained. If the content of the resin is less than 10 parts by weight, the number of voids to be formed tends to be small and the weight of the ceramic cannot be reduced, and the content of the resin is more than 95 parts by weight. In this case, although the number of generated voids increases, the amount of glass covering the surfaces of the voids decreases, and the effect of improving the strength of the ceramic tends to be insufficient. On the other hand, if the content of glass is less than 5 parts by weight, the amount of glass covering the surface of the voids tends to be small and the effect of improving the strength of the ceramic tends to be insufficient, and If the content of is more than 90 parts by weight, the amount of resin to generate voids is reduced and the number of voids generated is reduced, or the voids are filled with glass to reduce the weight of ceramics. This is because it tends to be impossible.

[0008] In the method for manufacturing ceramics according to the present invention,
It is preferable to add 1 to 150 parts by weight of the glass resin powder to 100 parts by weight of the ceramic material. If the amount of the glass resin particles is less than 1 part by weight, the number of voids formed is reduced and the weight of the ceramic tends not to be reduced. If the amount is more than 150 parts by weight, the amount of the ceramic raw material tends to be insufficient and the shape cannot be maintained during molding, and the generated voids tend to be continuous bubbles instead of independent bubbles. It is.

Further, in the method for manufacturing ceramics according to the present invention,
The average particle size of the glass resin particles is preferably larger than 100 μm and 5 mm or less. If the average particle size is 100 μm or less, the glass and the resin of the glass resin particles tend to be separated, and the production of the glass resin particles tends to be difficult. On the other hand, if the average particle size is larger than 5 mm, the moldability tends to deteriorate, and the strength of the produced ceramic tends to decrease.

Further, in the method for manufacturing a ceramic according to the present invention,
The glass resin powder may be characterized in that it contains a pulverized product of a glass-added resin material. The glass-added resin material is obtained by mixing glass fibers and glass powder into a resin as a matrix. By pulverizing the glass-added resin material, it is possible to easily obtain a granular material in which the glass and the resin are integrated. The pulverized product of the glass-added resin material can be suitably used as a glass resin powder, and particularly when the glass-added resin material is a waste material, the waste material can be effectively used.

A ceramic according to the present invention is manufactured by the above-described method for manufacturing a ceramic. The ceramic produced in this way is a porous ceramic having a large number of voids, and at least 5 of the voids.
0% or more is characterized in that the surface is covered with a glass film.

In this ceramic, at least 50% or more of a large number of voids are covered with a glass film, so that the strength is improved as compared with a conventional porous ceramic. In addition, since the glass film covering the surface of the void prevents moisture from entering the void, the risk of cracking or cracking due to the freezing and expansion of the moisture is reduced, and the frost damage resistance is improved. .

In the ceramic according to the present invention, it is preferable that the glass film has a thickness of 1/20 or more with respect to the diameter of the gap. The thickness of the glass film is 1 /
If it is smaller than 20, it tends to be difficult to completely cover the void surface due to irregularities on the void surface.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for manufacturing a ceramic and a ceramic according to the present invention will be described below with reference to the accompanying drawings as necessary. In the following description, “parts” and “%” indicating the quantitative ratios are based on weight unless otherwise specified.

In the method for manufacturing ceramics according to the present embodiment, a glass material powder is added to ceramics raw material, and molded.
It is characterized by firing at a temperature of 0 ° C. or higher.

The ceramic raw material usable in the present embodiment is not particularly limited. For example, it may be made of clay and feldspar, and may contain pottery stone, quartzite, pyroxene, or the like. For example, a typical composition in a ceramic raw material including clay, feldspar, and porcelain includes 60 parts by weight of clay, 20 parts by weight of feldspar, and 20 parts by weight of porcelain stone. In the case of fine ceramics, easily sinterable alumina, easily sinterable zirconia, or the like is used as a ceramic material. The ceramic raw material may further include an aggregate, a pigment, and the like.

In the present embodiment, the glass resin particles refer to powders and particles in which glass and resin are integrated as described above. In this glass resin powder, the state of integration is not limited as long as the glass and the resin are integrated. For example, as shown schematically in FIG. 4 is covered, and as schematically shown in FIG.
The resin 8 may be adhered to the resin.

Examples of the resin constituting the glass resin particles include polyethylene (PE; high density, low density), polypropylene (PP), polystyrene (PS), acrylonitrile / butadiene / styrene copolymer (AB)
S), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (P
A), polyphenylene sulfide (PPS), acrylic (PMMA), polycarbonate (PC), polysulfone (PSF), modified polyphenylene oxide (P
PO) and other thermoplastic resins, unsaturated polyester resins,
Phenolic resin, epoxy resin, vinyl ester resin,
Any of thermosetting resins such as melamine resin and DAP resin can be used. The above resins may be used alone or in combination of two or more as required.

The glass constituting the glass resin particles is based on SiO 2, and is, for example, soda glass (typical composition: 70 SiO 2, 10 CaO, 15 Na 2 O) or borosilicate glass (typical composition: 80SiO2,15B2O3,5Na2O).

Here, in the method for manufacturing ceramics according to the present embodiment, it is preferable that 100 parts by weight of the glass resin particles contain 10 to 95 parts by weight of the resin component and 5 to 90 parts by weight of the glass component. . More preferably, the resin content is 20 to 40 parts by weight, and the glass content is 20 to 30 parts by weight. If the content of the resin is less than 10 parts by weight, the number of voids to be formed tends to be small and the weight of the ceramic cannot be reduced, and the content of the resin is more than 95 parts by weight. In this case, although the number of generated voids increases, the amount of glass covering the surfaces of the voids decreases, and the effect of improving the strength of the ceramic tends to be insufficient. On the other hand, if the content of glass is less than 5 parts by weight, the amount of glass covering the surface of the voids tends to be small and the effect of improving the strength of the ceramic tends to be insufficient, and If the content of is more than 90 parts by weight, the amount of resin to generate voids is reduced and the number of voids generated is reduced, or the voids are filled with glass to reduce the weight of ceramics. This is because it tends to be impossible.

In the method for manufacturing ceramics according to the present embodiment, it is preferable to add 1 to 150 parts by weight of the above glass resin powder to 100 parts by weight of the above ceramic material. More preferably, the addition amount of the glass resin powder is 5 to
100 parts by weight. If the amount of the glass resin particles is less than 1 part by weight, the number of voids formed is reduced and the weight of the ceramic tends not to be reduced. If the amount is more than 150 parts by weight, the amount of the ceramic raw material tends to be insufficient and the shape cannot be maintained during molding, and the generated voids tend to be continuous bubbles instead of independent bubbles. It is.

In the method for manufacturing ceramics according to the present embodiment, the average particle size of the glass resin powder is preferably larger than 100 μm and 5 mm or less. Average particle size is 100μ
If it is less than m, the glass and the resin of the glass resin particles tend to separate from each other, and the production of the glass resin particles tends to be difficult. The average particle size is 5 mm
If it is larger than this, the moldability tends to be poor and the strength of the porcelain produced tends to decrease.

Here, the particle diameter of the glass resin particles is, for example, in the particle 1 having a shape as shown in FIG.
It is determined as the average of the longest diameter and the shortest diameter. FIG.
In the case of the powdery granular material 1 in which the resin adheres to the fibrous glass as shown in (b), it is determined as the average of the maximum diameter and the longest diameter of the resin portion. The average particle size of the glass resin particles described above is obtained as an average of the particle sizes of the individual particles thus obtained.

In the method for manufacturing ceramics according to the present embodiment, the glass resin particles may include a crushed product of a glass-added resin material. The glass-added resin material is obtained by mixing glass fibers and glass powder into a resin as a matrix. By pulverizing the glass-added resin material, it is possible to easily obtain a granular material in which the glass and the resin are integrated. The pulverized product of the glass-added resin material can be suitably used as a glass resin powder, and particularly when the glass-added resin material is a waste material, the waste material can be effectively used.

As the glass-added resin material, a material obtained by adding glass fiber or glass powder to an unsaturated polyester resin as a matrix, an epoxy resin or a vinyl ester resin as a matrix, a glass fiber,
Alternatively, glass powder may be added. In addition, glass fiber to polypropylene as a matrix,
Alternatively, a material obtained by adding glass powder or a material obtained by adding glass fiber or glass powder to polybutylene terephthalate as a matrix can be used. Glass fiber is mainly added to improve material strength, and glass powder is mainly added to suppress shrinkage and improve surface hardness.

These glass-added resin materials are used for mechanical parts,
It is used in various places in daily life, such as automobile parts and building parts, but after use it is currently incinerated as waste material. Therefore, resources can be effectively used by using the crushed material obtained by crushing the waste material of the glass-added resin material as the glass resin powder.

In particular, a resin (GFRP) obtained by adding a glass fiber as a reinforcing material to a thermosetting or thermoplastic resin as a matrix is widely used, but a regeneration processing technique and its use have not been established. After the useful life has passed, it must be disposed of as waste material, and most of the disposal is incinerated and landfilled, making it difficult to treat.
In the present embodiment, the effective use and recycling of the waste material are achieved by reusing the GFRP waste material.

Examples of such GFRP waste materials include unsaturated polyester resin containing glass fiber as a reinforcing material, a filler containing glass frit, calcium carbonate, aluminum hydroxide or the like as a filler, and unsaturated polyester resin containing glass fiber as a reinforcing material. Bath tubs and wash basins made of artificial marble containing glass frit, aluminum hydroxide or the like as a filler, other boats, septic tanks, toilet bowls, and resin forms as construction materials.

In the method for manufacturing ceramics according to this embodiment,
After being formed into a desired shape by using the above-described material, firing is performed at a temperature of 1000 ° C. or higher at which the glass contained in the glass resin powder is melted. When manufacturing sanitary porcelain such as tiles and toilets, the firing temperature is about 1000 ° C. to 1300 ° C., and when manufacturing fine ceramics using easily sinterable alumina or sinterable zirconia as a raw material, The firing temperature is about 1000 ° C to 1700 ° C. If the firing temperature is lower than 1000 ° C., the glass does not melt,
Alternatively, the melting of the glass becomes incomplete and the entire surface of the void is not covered with the glass.

The ceramic thus produced is a porous ceramic having a large number of voids, and at least a part of the large number of voids is covered with a glass film. FIG. 2 is a micrograph showing a cross-sectional structure of a tile as a porcelain manufactured by the above-described manufacturing method. As shown in the figure, the surface of the void is covered with a glass film formed by melting glass contained in the glass resin powder.

In this ceramic, since the surface of the void is covered with the glass film, the strength against bending and the like is improved as compared with the conventional porous ceramic. Further, since the glass film covering the surface of the gap prevents the intrusion of moisture into the gap, the risk of cracking or cracking due to the freezing and expansion of the moisture entering the gap is reduced,
Frost damage resistance is improved.

In the ceramics according to the present embodiment, the number and size of the voids vary depending on the amount and size of the glass resin powder added. Further, it is preferable that all the voids are covered with the glass film, but the glass film and the resin of the glass resin particles are separated during the mixing process of the ceramic material and the glass resin particles, and the glass film is separated. Voids that are not covered by can also occur. Even in this case, if 50% or more of the many voids are completely covered with the glass film, the strength and frost damage resistance can be improved as compared with the case where the glass film is not covered at all. Porous porcelain having at least 50% of voids covered by porcelain is included in the concept of the present invention. However, in order to sufficiently improve the strength and frost damage resistance of the ceramic, it is preferable that 90% or more of the many voids are covered with the glass film.

Here, the glass film covering the surface of the void is:
It is preferable to have a thickness that is 1/20 or more with respect to the diameter of the gap and that the gap is not filled. More preferably, the thickness of the glass film is 1/20 to the diameter of the void.
More than 1/2. If the thickness of the glass film is smaller than 1/20 with respect to the diameter of the gap, it is difficult to completely cover the gap surface due to the unevenness of the gap surface. Further, if the thickness of the glass film is larger than 1/2 of the diameter of the gap, the weight of the ceramic tends to be insufficiently reduced. In addition, since the average particle diameter of the glass resin particles is preferably larger than 100 μm and 5 mm or less, the diameter of the void is 100 μm to 5 m.
m, so that the thickness of the glass coating is 5 μm
It is preferably about 2.5 m.

Since there are various shapes such as an approximately spherical shape and an ovoid shape, the diameter of the void in this embodiment means the average of the longest diameter and the shortest diameter of the void.

As described in detail above, in the method for manufacturing ceramics according to the present embodiment, the glass resin powder is added to the ceramics raw material and fired at a temperature of 1000 ° C. or more at which the glass melts. After the resin component in the glass resin particles is burned in the firing process to generate a void, the glass component present in the void is melted and covers the surface of the void. In the ceramics manufactured in this way, since the surface of the void is covered with the glass film, the strength is improved as compared with the conventional porous ceramics. In addition, since the intrusion of moisture into the voids is suppressed by the glass film covering the surface of the voids, the risk of cracking and cracking due to the freezing and expansion of the moisture is reduced, and the frost damage resistance is improved. You.

Further, since it is not made porous by adding a foaming agent, dimensional accuracy and shape stability are high. Less than,
The present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0037]

[Example] (Materials used) Ceramic material : Frog-eye, Kibushi clay (Seto, Tajimi product) 60
20 parts by weight, feldspar (from Shigaraki), 2 parts by clay (from Okayama)
0 parts by weight of a ceramic raw material was used. Glass resin powder : Bathtub (INA) as GFRP waste material
X (manufactured by Company X). This bathtub contained unsaturated polyester resin containing glass fiber as a reinforcing material and calcium carbonate as a filler. The average particle size of this pulverized product was 20 μm. In addition, this crushed material 10
The 0 parts by weight contained 30% by weight of resin and 25% by weight of glass.

(Method of Preparing a Cured Body) Each raw material other than water, that is, a ceramic raw material and a glass resin powder were dry-mixed using a stirrer, and water was added to the obtained mixture, and further wet-mixed with a stirrer.

Next, kneading was performed using a kneader. The obtained kneaded material is put into a vacuum extruder and extruded,
A molded body having a width of 30 x a thickness of 15 x a length of 200 mm was produced.

This was calcined at a temperature of 1250 ° C. for 3 hours, cooled naturally, and the following physical properties were measured for the obtained cured product.

(Method of Measuring Physical Properties of Cured Body) (1) Flexural strength JIS A 5209 “Evaluation method of ceramic tile”, 7
According to the test method, 7.9 bending test, span 50 mm,
The bending strength of the cured product was measured at a load speed of 1 mm / min. (2) Water absorption JIS A 5209 “Evaluation method of ceramic tile”, 7
The water absorption of the molded article was measured according to the test method, 7.6 water absorption test. (3) Frost damage test JIS A 5209 “Evaluation method of ceramic tile”, 7
According to the test method, 7.12 frost resistance test, the produced cured product was immersed in water for 24 hours to absorb water, and then left in an environment at a temperature of −20 ° C. for 8 hours. Thereafter, it was examined whether or not the cured product had cracks or cracks.

Example 1 In Example 1, 10 parts by weight of the above-mentioned glass resin powder was added to 100 parts by weight of the above-mentioned ceramic raw material, followed by dry mixing with a stirrer. Further, only 30 parts by weight of water was added and wet-mixed, and then kneaded with a kneader. Then, the obtained kneaded material was extruded to obtain a molded body having a width of 30 x a thickness of 15 x a length of 200 mm, which was then fired at a temperature of 1250 ° C for 3 hours.
After natural cooling, the physical properties described above were measured for the obtained cured product.

Example 2 In Example 2, a cured product was produced under the same conditions as in Example 1 except that the amount of the glass resin powder was 40 parts by weight. The physical properties described above were measured for the body.

Example 3 In Example 3, a cured product was produced under the same conditions as in Example 1 except that the amount of the glass resin powder was 100 parts by weight. The physical properties described above were measured for the body.

Comparative Example 1 Comparative Example 1 was carried out except that 10 parts by weight of an unsaturated polyester resin powder was added to 100 parts by weight of the above-mentioned ceramic material in place of the glass resin powder. A cured product was produced under the same conditions as in Example 1,
The physical properties described above were measured for the obtained cured product.
The average particle size of the unsaturated polyester resin particles is
The average particle diameter of the glass resin particles in the examples was the same.

Comparative Example 2 In Comparative Example 2, a cured product was obtained under the same conditions as in Comparative Example 1 except that the amount of the unsaturated polyester resin powder added was 40 parts by weight. The properties of the cured product were measured as described above.

Comparative Example 3 In Comparative Example 3, a cured product was obtained under the same conditions as Comparative Example 1 except that the amount of the unsaturated polyester resin powder was changed to 100 parts by weight. The properties of the cured product were measured as described above.

The results obtained in Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1.

[0049]

[Table 1]

As shown in Table 1, as compared with the ceramics of Comparative Examples 1 to 3 in which the particles of the unsaturated polyester resin were added, Examples 1 to 3 in which the glass resin particles were added were used. In ceramics, strength is improved and frost damage resistance is improved. Improvement of frost damage resistance is shown in Examples 1 to
This is supported by the fact that the water absorption of the ceramic of No. 3 has decreased. In addition, except that the firing temperature was set to 900 ° C., it was confirmed that the same results as those of Comparative Examples 1 to 3 were obtained with respect to the bending strength and the frost damage resistance of the porcelain produced under the same conditions as Examples 1 to 3. I have.

[0051]

In the method for manufacturing ceramics according to the present invention, glass resin powder is added to the ceramics raw material, molded and fired at a temperature of 1000 ° C. or higher at which the glass melts. After the resin component in the glass resin powder is burned to generate voids, the glass component present in the voids melts and covers the surface of the voids. In the ceramics according to the present invention manufactured as described above, since the surface of the void is covered with the glass film, the strength can be improved as compared with the conventional porous ceramics. In addition, since the intrusion of moisture into the voids is suppressed by the glass film covering the surface of the voids, the risk of cracking or cracking due to the freezing and expansion of the moisture is reduced, and the improvement of the frost damage resistance is improved. It becomes possible to plan.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of the shape of a glass resin powder.

FIG. 2 is a photomicrograph showing a cross-sectional structure of a ceramic tile as the embodiment.

[Explanation of symbols]

1 ... Glass resin powder, 2,6 ... Glass, 4,8 ... Resin.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junko Takada 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Seiji 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Tsunemi Sugie 5-1-1 Koiehonmachi, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Takamichi Kobayashi 5-1-1 Koiehonmachi, Tokoname-city, Aichi F-Term (Inax Corporation) 4G019 KA01

Claims (8)

[Claims] 1. A method for producing a ceramic, comprising adding a glass resin powder to a ceramic raw material, molding and firing at a temperature of 1000 ° C. or higher. 2. The ceramic material according to claim 1, wherein 100 parts by weight of the glass resin powder contains 10 to 95 parts by weight of a resin component and 5 to 90 parts by weight of a glass component. Production method. 3. The method according to claim 1, wherein 1 to 150 parts by weight of the glass resin powder is added to 100 parts by weight of the ceramic raw material. 4. An average particle size of the glass resin powder is 1
The method according to any one of claims 1 to 3, wherein the diameter is larger than 00 µm and 5 mm or less. 5. The method according to claim 1, wherein the glass resin powder contains a pulverized glass-added resin material. 6. A ceramic produced by the method for producing a ceramic according to claim 1. 7. A porous ceramic having a large number of voids, wherein at least 50% or more of the large number of voids are covered with a glass film. 8. The ceramic according to claim 7, wherein the glass coating has a thickness of 1/20 or more with respect to a diameter of the gap.