JP2912126B2 - Ceramic plate and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porcelain plate manufactured by a papermaking method and a method of manufacturing the same, and more particularly, to a thin and large-sized porcelain plate which is less warped or deformed and has excellent strength characteristics. The present invention mainly relates to a ceramic plate suitable for use as an outer wall material, an inner wall material, a floor material, and the like of a building, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the market for large-sized ceramic plates has been rapidly expanding. This large ceramic plate is required to be lightweight in consideration of ease of handling and ease of construction, and is usually manufactured as a thin plate. However, even if the ceramic plate is a thin plate, the ceramic plate has sufficiently excellent strength characteristics against external impact,
In addition, it is required that there is no warpage or deformation and that good dimensional accuracy is provided.

As a method for manufacturing such a thin ceramic plate, a papermaking method is generally applied.
The following method is proposed in Japanese Patent Publication No. 0-3038. That is, a slurry containing high earth powder and a fiber material as essential components is manufactured to produce a ceramic plate sheet having a predetermined amount of water content, and a slurry containing a glaze and a fiber material as essential components is formed. This is a method in which a glaze sheet having a predetermined amount of water content is produced, the two sheets are overlapped, integrated using a roll-type press, and then fired.

In addition, the present inventors have manufactured a thin paper sheet by forming a slurry comprising a powder of a ceramic material, a fiber material, and a binder component, laminated the required number of the formed paper sheets, and added the entirety. Then, a method for manufacturing a ceramic plate having a multilayer structure composed of a sheet-like fired body having the same composition was proposed (see Japanese Patent Application No. 4-58906).

Incidentally, it is preferable that the ceramic plate has no warp or deformation as a whole and has a smooth and dense structure on its surface. Smooth surface means that the surface has no corrugated irregularities and the aesthetic appearance of the ceramic plate improves, and that the surface has a dense structure means that the water absorption of the ceramic plate This is because it is possible to suppress the occurrence of problems such as surface contamination due to water absorption, frost damage, and susceptibility to scratching.

When a ceramic plate having a dense structure is to be manufactured by using the above-mentioned papermaking method, the papermaking sheet is usually moved around a roller of a roller hearth kiln, for example, while the sintering temperature is around. At this temperature, the paper sheet is fired to promote shrinkage of the paper sheet as a whole. However, when the sheet is heated to a temperature near its sintering temperature, the sheet is softened as a whole and moves on the rollers in the softened state. Therefore, for example, if the temperature of the kiln fluctuates even if the temperature is slight, the softened sheet is sagged by its own weight, and as a result, corrugated irregularities are likely to be generated on the surface of the fired sheet, and the smoothness of the plane is reduced. The problem of being hindered comes up.

The porcelain plate manufactured by the method described in the above-mentioned Japanese Patent Application No. 4-58906 has excellent impact resistance and strength characteristics, and has excellent dimensional accuracy without warpage or deformation as a whole. However, if the surface is made to have a dense structure, corrugated unevenness may also be generated on the surface for the above-mentioned reason.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to Japanese Patent Application No.
The above-mentioned problems in the ceramic plate manufactured by the method described in No. 58906 and the method for manufacturing the same are solved, the impact resistance and the strength characteristics are excellent, and there is no warpage or deformation as a whole, and the surface is dense. An object of the present invention is to provide a ceramic plate having a structure and having no corrugated unevenness deformation on its surface and a method for manufacturing the same. Also, the exterior of the building using the ceramic plate
Materials, architectural interior materials, architectural floorboards, furniture top plates, indoor cows
The purpose is to provide the center.

[0009]

In order to achieve the above-mentioned object, the present invention provides a ceramic plate in which two or more sheet-like fired bodies mainly composed of a ceramic material are laminated, A ceramic plate is provided, wherein at least two of the sheet-like fired bodies have different softening temperatures from each other, and a powder of a ceramic material, a fiber material, and a glass transition point of 10 ° C. or lower. At least two types of slurries containing the thermoplastic organic material as an essential component, wherein at least two types of slurries each having a different softening temperature when sintering a sheet-like molded product obtained by forming each of the slurries. Prepare different types of slurry,
At least two sheet-shaped molded articles are separately formed from each slurry, and the obtained sheet-shaped molded articles are laminated to form a laminate having at least a two-layer structure. There is provided a method for manufacturing a ceramic body, characterized by firing.

[0010] The ceramic plate of the present invention is formed by laminating at least two sheet-like molded articles obtained by forming a slurry described later,
By pressing the laminated body, the sheet-like molded bodies are pressed together and integrated, and then the whole is fired to convert each sheet-like molded body into a sheet-like fired body mainly composed of a ceramic material. Manufactured. Here, each sheet-like molded body to be laminated is obtained by paper-making a slurry described later, and at least two of them are formed by sintering them into a sheet-like fired body. It is composed of a slurry such that the softening temperature of the shaped body becomes different. In particular,
It is a sheet made by forming a slurry obtained by adjusting the composition and the type of the ceramic material as the main component.

Therefore, the ceramic plate of the present invention has a multilayer structure in which two or more sheet-like fired bodies having different softening temperatures are laminated. The softening temperature in the present invention refers to a value determined as follows. That is,
First, dye water is impregnated in the thickness direction from the surface of the ceramic plate obtained by firing. Since each layer of the sheet-like fired body has a different pore structure, there is a difference in shading in the dyed state of each layer corresponding to the difference in the pore structure. Therefore, by observing the difference in density of each layer with, for example, a microfiber scove, the interface between the layers can be identified, and the thickness of each layer can be measured at the same time.

When the difference in the pore structure between the layers is small,
The difference in composition in the thickness direction is obtained by EPMA, whereby each layer can be identified. After identifying each sheet-like fired body in this manner, the ceramic plate is carefully sliced, a layer of the sheet-like fired body to be measured is collected as a sample, and the sample is heated in a furnace to start deformation. Temperature.

[0013] Specifically, the above-mentioned sample was prepared with a thickness of 2 mm.
Processed into a plate with a width of 10 mm and a length of 100 mm.
It is placed symmetrically on two fulcrums separated by 80 mm, set in an electric furnace as it is, and heated at a heating rate of 10 ° C./min. The temperature at which the amount reaches 10% of the thickness of the plate is defined as the softening temperature.

When the above-mentioned sheet-like molded body is fired, if the firing temperature is increased, the pyrolysis components in the molded body are thermally decomposed at each decomposition temperature and gasified and volatilized. The molded body shrinks due to heat shrinkage. At this time, the higher the firing temperature, the higher the degree of densification. And when sintering is completed,
Micropores and the like that have been opened on the surface of the molded body are closed, and the surface has a dense structure that approximates a non-porous state.

Therefore, in such a surface state, the obtained fired body does not substantially absorb water, and the water absorption of the sheet-like fired body is observed as zero here.
Here, the above-mentioned water absorption is a value obtained as follows. That is, in the same manner as in the measurement of the softening temperature described above, the ceramic plate obtained by firing is carefully sliced, and a layer of the sheet-like fired body to be measured is collected as a sample. After drying for 3 hours, the sample was allowed to cool to room temperature in a desiccator, and the weight (W ₁ ) of the sample was weighed. Then, the sample was immersed in water at room temperature for 24 hours to absorb water, and then the surface was wiped off. The weight (W ₂ ) is a value calculated based on the following formula: (W ₂ −W ₁ ) × 100 / W ₁ .

Considering the sintering process when manufacturing the ceramic plate of the present invention, the laminated body to be sintered includes a sheet-shaped compact having a relatively high sintering temperature and a relatively low sintering temperature. It contains at least two layers of sheet-like moldings. The firing temperatures of these sheet-like molded bodies are the same in both cases. However, the effect of the sintering temperature on each sheet-shaped molded product is not the same.

That is, the sintering temperature at that time has an effect similar to the effect of the inherent sintering temperature of the sheet-shaped formed body on the sheet-shaped formed body having a relatively low sintering temperature. The effect of the inherent sintering temperature of the sheet-shaped compact has a relatively far influence on the sheet-shaped compact having a relatively high sintering temperature.

Therefore, at the sintering temperature, the converted sheet-like sintered body obtained by converting the sheet-like molded body having a relatively low sintering temperature has a relatively dense structure and a high strength. Will be higher. On the other hand, a sheet-like fired body obtained by converting a sheet-like molded body having a relatively high sintering temperature has a relatively dense structure and a low strength, and therefore has a relatively low softening temperature.

Therefore, in the firing step, the strength of the sheet-like fired body having a relatively high sintering temperature (the sheet-like fired body having a high softening temperature) causes the strength of the sheet-like fired body having a relatively low sintering temperature (softening temperature). (A sheet-like fired body having a low thickness) is complemented, and as a result, sagging due to softening of the laminate in the firing process is suppressed, and corrugated unevenness deformation on the entire surface is suppressed. Become like

Therefore, for example, by using a sheet-like molded body having a relatively low softening temperature for the front layer and a sheet-like molded body having a relatively high softening temperature for the back layer, a structure having a dense surface can be obtained. It is possible to manufacture a ceramic plate having no corrugated irregular deformation. In the ceramic plate of the present invention, it is preferable that the difference in softening temperature between at least two layers of the sheet-like fired body constituting the same is adjusted to 10 ° C. or more. It is particularly preferable that the temperature be adjusted to 20 ° C. or higher.

In the case where the difference in softening temperature between the sheet-like molded bodies is smaller than 10 ° C., it is difficult to control the sintering temperature to be actually applied, and thus it is difficult to obtain the above-mentioned effects. . However, if the temperature difference is excessively large, the balance of the properties of the obtained porcelain plate will be lost. Therefore, the temperature is usually set within 300 ° C., preferably within 100 ° C., and more preferably within 50 ° C.

The ceramic plate of the present invention is manufactured as a multilayer structure of the above-mentioned fired sheet. The number of layers at that time is not particularly limited as long as it is at least two layers, but three layers are suitable, and more preferably 5 layers.
More than layers. When the number of layers of these sheet-like fired bodies increases, the uniformity of the entire ceramic plate increases, and the heat shrinkage of each sheet-like molded body during the firing process becomes uniform, causing warpage and distortion of the fired ceramic plate. Harder to do,
There is an advantage that the overall strength is also increased. Although the number of layers may be two, three or more layers, preferably five
More than layers. However, when the number of layers is excessively large, when a pressure treatment described below is performed on the laminate of the sheet-shaped molded body,
In general, the upper limit of the number of layers is set to 20 because the pressurizing effect is reduced and it becomes difficult to integrate the sheet-like molded bodies as a whole and there is a relationship with production equipment.

In the baking process described later, the respective components may be mixed with each other to form an intermediate layer at the interface between the sheet-like fired bodies. In the present invention, the intermediate layer is formed into a sheet-like shape. Not counted as a fired body layer. In addition,
Since the intermediate layer is formed by sintering a mixture of the components of the adjacent layers, the intermediate layer functions as a layer for adhering the adjacent layers, and thus has an effect of suppressing delamination.

The state of lamination of these sheet-like fired bodies is appropriately selected depending on the application and performance required for the entire ceramic plate. In the case of the two-layer structure, the front surface (back surface) and the back surface (front surface) are respectively composed of the above-described sheet-like fired body having a low softening temperature and the sheet-like fired body having a high softening temperature. In the case of the above multilayer structure, at least the surface layer is formed of a sheet-like fired body having a low softening temperature,
The back surface layer is preferably formed of a sheet-like fired body having a high softening temperature.

Further, a multi-layer structure of a sheet-like fired body in which the softening temperature gradually increases from the surface layer to the back layer may be adopted. Although the thickness of each sheet-like fired body in the ceramic plate of the present invention is appropriately determined depending on the desired thickness and characteristics of the ceramic plate, it is usually preferably 0.1 to 2 mm. In this case, the thickness of each sheet-like fired body may be the same or different.

The thickness of the fired sheet is determined by the thickness of the sheet used. And the thickness of the sheet-shaped molded body to be used can be adjusted by appropriately selecting the composition of the slurry and the papermaking conditions described below. Alternatively, a desired number of thin sheet-shaped molded articles having the same composition may be laminated, and the laminated article may be used as a sheet-shaped molded article having a desired thickness and the composition.

In the firing process for producing the ceramic plate of the present invention, the laminated sheet-like molded products shrink at a heat shrinkage ratio corresponding to the composition. In that case, at the mutual interface between the two sheet-shaped molded products having different properties after firing, a strain stress is applied to the interface between the formed sheet-shaped fired products based on the difference in the heat shrinkage of each sheet-shaped molded product. Will be inherent.

Therefore, even when an externally applied impact force is applied to the ceramic plate, the small fracture proceeds at the interface where the strain stress is present, and the impact force is absorbed or dispersed. The propagation of the impact force in the thickness direction of the plate is greatly suppressed, and the occurrence of cracks is suppressed. Also, when two sheet-like molded bodies having different thermal expansion coefficients after firing are fired in a state where they are pressed against each other, a compressive stress is generated in a layer having a low thermal expansion coefficient in the firing process, and thermal expansion is caused. A tensile stress is generated in a layer having a large coefficient.

Therefore, by optimizing the respective stresses occurring in the adjacent sheet-like fired bodies, it is possible to suppress the warpage and deformation of the obtained ceramic plate, and at the same time, to reduce the strength of the ceramic plate itself. Can be greatly increased. Considering this, the difference in coefficient of thermal expansion between the sheet-like fired bodies adjacent to each other is 0.2 × 10 ^−6.
It is preferable that the coefficient of thermal expansion of each sheet-like fired body is adjusted so as to be up to 2.0 × 10 ⁻⁶ / ° C. In particular, 0.
It is preferably adjusted to 5 × 10 ^{-6 to} 1.0 × 10 ^-6 / ° C. When the difference in the coefficient of thermal expansion is smaller than 0.2 × 10 ⁻⁶ / ° C., the above-mentioned effects are not sufficiently exhibited, and
If it exceeds 2.0 × 10 ⁻⁶ / ° C., delamination or cracks are likely to occur during the firing process, and warping or deformation will occur during the firing process.

In the ceramic plate of the present invention, it is preferable that the coefficient of thermal expansion of the sheet-like fired body having a low softening temperature is smaller than the coefficient of thermal expansion of the sheet-shaped fired body having a high softening temperature. Since the heat shrinkage during the firing process of the sheet-like molded body which is converted into the sheet-like fired body having a low softening temperature is small, a compressive stress is generated in the formed fired sheet having the low softening temperature, and as a result, its surface In this case, impact resistance and strength characteristics are improved.

The above-mentioned coefficient of thermal expansion refers to a value obtained as follows. That is, each layer of the resulting ceramic plate by firing carefully sliced After identified in the manner described above, a layer of sheet-form sintered body measured as a sample (a length l ₀ at room temperature) The sample is collected, the sample is set in a commercially available push-rod type differential thermal dilatometer, and the sample is heated from room temperature (t ₀ ° C) to a predetermined temperature (t ° C) to obtain a sample length (l). ) was measured, the following formula: is that of _{α = 1-l 0 / l} / t-t 0 average thermal expansion coefficient which is calculated on the basis of the alpha.
t is usually 400 ° C.

The ceramic plate of the present invention is manufactured as follows. First, at least two types of slurries are prepared. Each of these slurries contains a ceramic material powder, a fiber material, and a thermoplastic organic material as essential components.
As a ceramic material, it is not particularly limited,
For example, various clays, such as kaolin, pottery stone, silica sand, wollastonite, feldspar, dolomite, alumina, zirconia, fly ash, aplite, and anti-fire stone can be mentioned. Each of these may be used alone, or two or more of them may be used in a mixture at an appropriate ratio.

These are usually preferably used as fine powders of about 200 to 400 mesh (Tyler sieve). Examples of the fiber material include, but are not particularly limited to, various types of natural fibers, natural and synthetic pulp, regenerated fibers such as rayon, polyvinyl alcohol-based, polyacryl-based, polyamide-based, and polyester-based synthetic fibers. Various organic fibers such as; glass fiber,
Various inorganic fibers such as ceramic fibers, rock wool, and potassium titanate.

These may be used alone, respectively.
Two or more kinds may be used in appropriate combination. As the thermoplastic organic material to be blended in the slurry of the present invention, a polymer having a glass transition point of 10 ° C. or less as measured by differential thermal analysis (TGA) or differential scanning calorimetry (DSC) is used. Examples of such a polymer include natural rubber, synthetic rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyacrylate, polyurethane, polyolefin, polyamide, polyacrylamide, polyvinyl acetate, and ethylene-
And vinyl acetate copolymer. Each of these may be used alone, or two or more of them may be appropriately mixed and used.

This organic material gives flexibility to a sheet-like molded product obtained by forming a slurry. Then, in the process of laminating the sheet-like molded bodies and pressurizing the laminated body, the binding property between the respective sheet-like molded bodies is enhanced, whereby each sheet-like molded body can be used without using a separate binder. A molded article can be uniformly integrated. As a result, the flexibility of the laminate after pressing is improved. Further, by adjusting the blending amount of the organic material and the pressure in the pressurizing process described later, the porosity and the water absorption described later can be adjusted to appropriate values.

The slurry to be used is determined so that the softening temperature after firing of the sheet-like molded product obtained by forming the slurry is the desired softening temperature. Usually, the powder of the ceramic material as the main component is used. The mixing ratio of each component is set to 1 to 25 parts by weight, preferably 1 to 10 parts by weight, and 1 to 50 parts by weight, preferably 1 to 10 parts by weight of the thermoplastic organic material with respect to 100 parts by weight.

These components are mutually changed within the range of the mixing ratio described above to prepare a slurry for a sheet-like fired body having a lower softening temperature and a slurry for a sheet-like fired body having a higher softening temperature. You. The ratio of fiber material is 1
If the amount is less than the weight part, it becomes difficult to make a slurry, and the yield of the sheet-like molded body in the paper making process becomes poor.

When the above-mentioned organic fiber is used as the fibrous material, if the ratio is more than 25 parts by weight, when the organic fiber is decomposed by thermal decomposition in a firing step described later and disappears, the sheet-like molded article is not used. The heat shrinkage of the sheet becomes large, and the formed sheet-like fired body has a large warp and deformation, which makes it difficult to obtain a satisfactory ceramic plate. When the above-mentioned inorganic fiber is used as the fiber material, since the fiber material does not disappear during the firing process, the amount of shrinkage of the sheet-like molded body is suppressed, and the fire resistance of the obtained sheet-like fired body is further reduced. And the effect of suppressing warpage and deformation and improving the strength of the ceramic plate can be obtained. However, if the proportion is more than 10 parts by weight, there arises a problem that the density of the obtained ceramic plate does not increase.

Therefore, when organic fibers are used, 1 to 25% by weight of the ceramic material powder is used.
When inorganic fibers are used, the amount is preferably 1 to 10 parts by weight. In addition, the weight of both fibers is 2%.
You may mix and use about 0: 80-80: 20. When the proportion of the thermoplastic organic material is less than 1 part by weight, the above-mentioned effects of the organic material are not sufficiently exhibited. When the proportion is more than 50 parts by weight, the effect of thermal decomposition in the firing process of the organic material is caused. However, the amount of shrinkage of the obtained ceramic plate is too large, which is not preferable.

The slurry used in the present invention contains the above three components as essential components. In addition to these components, the quality and performance of the target ceramic plate can be improved, and each step in the production can be smoothly performed. In order to proceed, various drugs may be blended. Examples of such agents include, for example, an anionic organic polymer electrolyte solution, a cationic organic electrolyte solution, a cationic inorganic colloid solution, a fixing agent or a flocculant such as a polyvalent metal salt, asbestos fiber, and glass fiber. And dehydration aids such as inorganic powders such as wollastonite.

Further, for the purpose of coloring a ceramic plate or exhibiting a design effect, for example,
Various pigments, colored fine particles, fine particles of natural granite and the like may be dispersed. The above components are put into water at a predetermined ratio, and the whole is stirred and mixed using, for example, a known pulper to prepare a slurry for papermaking. At that time, the solid concentration of the slurry is usually 0.5 to
It is adjusted to 10% by weight. Preferably, it is adjusted to 1 to 5% by weight.

In the present invention, at least two types of slurries are prepared. That is, it is at least two types of slurries such that the softening temperatures of the two types of sheet-like formed bodies obtained by paper-making these slurries after firing are different from each other. At least two types of slurries are separately formed using, for example, a known long net or round net type paper making machine, and at least two types of sheet-like formed bodies are separately formed. The thickness of the molded body is usually adjusted to be 0.1 to 10 mm.

Next, the obtained sheet-like molded body is subjected to a drying treatment by using, for example, a known roll dryer or tunnel dryer. The moisture content of the sheet-like molded product after the drying treatment is not particularly limited. Usually, it is easy to handle in the next laminating step, adjusting the porosity and water absorption of the laminate after pressing to a suitable value, and the binding effect between the sheet-like molded articles after pressing. In order to improve the water content, it is desirable to set the conditions during the drying treatment so that the water content is 2% by weight or less, preferably 1% by weight or less.

Each of the sheet-like molded bodies after the drying treatment is laminated to have a desired layer structure, and then the laminated body is pressed, and the respective sheet-like molded bodies are pressed against each other. Be integrated. As the press at this time, for example, a known flat press or roll press can be used. In particular, a roll press is preferable because a long sheet-like molded body can be uniformly and continuously pressed efficiently.

The applied pressure should be at least 100 in linear pressure.
It is preferable to set the pressure to at least kg / cm, preferably at least 300 kg / cm, more preferably at least 500 kg / cm. When the linear pressure is less than 100 kg / cm, the binding force between the sheet-like molded products becomes small, and in the next baking process, delamination tends to occur between the formed sheet-like molded products, and This is because it becomes difficult to adjust the porosity described later in the range of 0.1 to 0.4.

If each sheet-like molded body is heated in advance before the above-mentioned pressurizing treatment, a dense and distortion-free laminate can be obtained even if the linear pressure during the pressurizing treatment is low. This is preferable. In this case, it is preferable to heat the sheet-shaped molded body to a temperature higher than the glass transition point of the thermoplastic organic material contained by 50 ° C or more. At such a temperature, it is considered that the thermoplastic organic material is sufficiently softened and the tackiness is increased, and as a result, even at a low pressure, the binding property between the respective sheet-shaped moldings is improved. Can be

In this way, a laminated body in which each sheet-like molded body is integrated in a multilayer structure is obtained. In the present invention, the porosity of this press-laminated product is adjusted to the range of 0.1 to 0.4, and the water absorption is adjusted to the range of 10 to 30%, particularly to the range of 15 to 25%. It is preferred that

The porosity and water absorption of these laminates are
As mentioned above, the slurry composition, especially the glass transition point,
Mixing ratio of thermoplastic organic material below 10 ° C
By appropriately selecting the pressing force in the pressing process of the layer body
Can be adjusted. The porosity here means
Formula: 1- [W₀/ V₀] / [W₁・ Ρ₁+ W_Two・ Ρ_Two] / W
₀ (However, in the formula, V₀Dry the laminate at 105 ° C for 24 hours
Laminate volume after drying: cm^Three, W₀Is 10
Weight of laminate after drying at 5 ° C. for 24 hours: g, W₁
Is to reduce the laminate after drying the laminate at 400 ° C. for 2 hours.
Small weight: g, W _TwoWas dried at 400 ° C. for 2 hours.
Residual weight of laminated body after: g, ρ₁Is included in the laminate
Density of the whole organic material: g / cm^Three, Ρ_TwoIs included in the laminate.
Density of whole inorganic material: g / cm^ThreeRepresents)
It is a value calculated based on this.

The water absorption (%) means that the laminate
And dried at room temperature for 2 hours at room temperature.
After immersion for 4 hours to absorb water, the water on the surface is wiped off and the weight before and after the water absorption test is calculated based on the following formula: (weight after water absorption test-weight before water absorption test) x 100 / weight before water absorption test. It is a value that is calculated.

Among these characteristics, for example, the porosity is a factor that affects the shrinkage ratio in the firing process of the laminate. Conventionally, in the production of a ceramic plate, if the porosity is reduced, the warpage will occur in the firing process. It is known that when the porosity is increased, the shrinkage during the firing process is increased. Therefore,
It is preferable to reduce the porosity when manufacturing a ceramic plate with less warpage and deformation, but since the laminate having a small porosity contains a relatively large amount of inorganic material,
Poor flexibility and brittleness make it an unsuitable material that is difficult to handle as a laminate for a thin and large-sized ceramic plate.

However, the laminate used in the present invention is:
Since a relatively large amount of ceramic materials and fiber materials are contained and the porosity is small, a predetermined amount of a thermoplastic organic material having a glass transition point of 10 ° C. or less is also blended. And overall handling becomes easy. Therefore, even if the porosity is not more than 0.4 which is considered unsuitable in the laminate used for the production of the conventional ceramic plate, in the case of the laminate used in the present invention, in the process of firing it,
Significant heat shrinkage does not occur so much, and as a result, occurrence of warpage and deformation is suppressed, and a ceramic plate having a smooth entire surface can be obtained. However, if the porosity is smaller than 0.1, the laminate is in a state of being excessively compressed, so that cracks and warpage occur during the firing process due to the residual stress generated during pressurization. It happens frequently.

From the above, the porosity of the laminate is set to 0.1.
It is preferable to adjust to 1 to 0.4. The laminate obtained as described above is then fired at a temperature of 1000 to 1350 ° C., preferably 1000 to 1300 ° C. using, for example, a known roller hearth kiln, and is generated during the firing process. Each sheet-like molded body is converted into a sheet-like fired body while quickly removing the decomposition gas coming out, and the ceramic plate of the present invention is manufactured as a multilayer structure of these sheet-like fired bodies.

In this firing step, the heating rate in the temperature range of 250 to 500 ° C. is 20 ° C./min or less, particularly 10 ° C./min.
/ Min or less is preferable. If the heating rate in the above temperature range is excessively high, a decomposition gas accompanying the thermal decomposition of the organic fibers and the thermoplastic organic material contained in the laminate is rapidly generated, or abnormal heat generation of the sheet-like fired body. This is because delamination frequently occurs between the layers.

In the above manufacturing process, a slurry containing a pigment of a desired color is formed to produce sheet-like molded articles of various colors, and the sheet-like molded articles constitute the entire surface layer. Also, when the surface layer and the back surface layer are formed of sheet-shaped molded bodies of different colors, or when each layer is formed of a sheet-shaped molded body of a different color, the obtained ceramic plate exerts various design effects. be able to.

In the pressing step, a desired concavo-convex pattern is imparted to the surface by using an embossing roll as a pressing machine, and further, a glaze paper or a pattern printing film is attached to the surface of the ceramic plate to thereby form the surface. Various patterns can be provided. Furthermore, in the present invention, the laminated body after pressurizing is temporarily calcined at a temperature of, for example, 800 to 1350 ° C., and then the desired surface is coated with a desired glaze.
By sintering at a temperature of 0 to 1350 ° C., a glazed ceramic plate can be manufactured.

[0056]

【Example】

Examples 1-4, Comparative Examples 1 and 2 Ceramic material powder consisting of 35 parts by weight of feldspar, 35 parts by weight of silica, 5 parts by weight of kaolin, 20 parts by weight of wollastonite, 5 parts by weight of kraft pulp Department and
5 parts by weight of an acrylic emulsion (glass transition point: −5 ° C.) were added to water, and the whole was sufficiently stirred to prepare a slurry (A) having a solid concentration of 2% by weight.

A ceramic material powder comprising 30 parts by weight of feldspar, 35 parts by weight of silica, 10 parts by weight of kaolin, 20 parts by weight of selven, 5 parts by weight of wollastonite, 5 parts by weight of kraft pulp, and acrylic ermajon (Glass transition point: -5 ° C.) 5 parts by weight of the mixture was poured into water, and the whole was sufficiently stirred to obtain a slurry (B) having a solid concentration of 2% by weight.
Was prepared.

A ceramic material powder consisting of 25 parts by weight of feldspar, 35 parts by weight of silica, 15 parts by weight of kaolin, 20 parts by weight of selven, and 5 parts by weight of wollastonite, 5 parts by weight of kraft pulp, and an acrylic emulsion ( (Glass transition point: −5 ° C.) and 5 parts by weight into water, and then thoroughly stirred to prepare a slurry (C) having a solid concentration of 2% by weight.

These slurries (A), (B) and (C)
From, by using Fourdrinier paper machine, width 120cm
The endless sheets are separately formed, and the respective sheets are passed through a multi-cylinder dryer, and the sheet-shaped molded articles (A) and the sheet-shaped molded articles (A) each having a water content adjusted to 0.5% by weight are prepared. B) and a sheet-shaped molded body (C) were separately manufactured. The thicknesses of these sheet-like molded articles (A), (B) and (C) were adjusted to 2.2 mm, 2.4 mm and 2.1 mm, respectively.

Each of these sheet-like molded bodies was fired at a temperature of 1200 ° C. using a roller hearth kiln, and the resulting fired sheet was processed to have a thickness of 2 mm, a width of 10 mm, and a length of 10 mm.
These specimens were placed on a fulcrum having a span length of 80 mm, set in an electric furnace, heated at a rate of 10 ° C./min, and the amount of droop at the center of the specimen was 0.2 mm. At which point the temperature was reached.

As a result, the softening temperature of the sheet-shaped molded product (A) was 1200 ° C., and the softening temperature of the sheet-shaped molded product (B) was 1
210 ° C., softening temperature of the sheet-like fired body (C) is 1245
° C. Next, these sheet-like molded bodies were laminated in a manner as shown in Table 1 to form a laminated body, and the whole was passed through a hydraulic calender roll having a linear pressure of 350 kg / cm.

The pressed laminate was cut in the longitudinal direction to obtain a green having a length of 3 m and a width of 1.2 m. The porosity and water absorption of this green were measured. Then, the green is fired at a temperature of 1200 ° C. for 60 minutes using a roller hearth kiln to obtain a fired sheet (A), which is a fired sheet (A), and a fired sheet (B). And a sheet-like fired body (C), which is a fired body of the sheet-like molded body (B), were laminated and integrated into a ceramic plate.

Dye water was impregnated from the surface of each of the obtained ceramic plates, and the cross section was microfiberscope (magnification: 10).
(0x), it was possible to identify each layer of the ceramic plate. Then, the water absorption of the sheet-like fired body (A), the sheet-like fired body (B), and the sheet-like fired body (C) in each ceramic plate was measured. Then, for each surface of the ceramic plate, the density of the surface is evaluated by a five-level evaluation of glossiness (grade: evaluation point 5 is the best), and a five-level evaluation of the degree of corrugation unevenness (grade: evaluation point 5 is the best). The surface antifouling property (grade: evaluation point 5 is best) is determined by a five-step evaluation of surface contamination after horizontal exposure 6 months test, respectively.
In addition, the warpage and deformation of the entire ceramic plate were evaluated on a 5-point scale (grade: evaluation point 5 is best).

The above results are shown in Table 1 collectively.

[0065]

[Table 1] Example 5, Comparative Examples 3 and 4 The same conditions as in Example 4 except that the blending amount of the acrylic emulsion and the linear pressure of the calender roll were changed as shown in Table 2 in Example 4. Produced a ceramic plate having a five-layer structure.

The properties of the green and ceramic plates used for these ceramic plates were measured in the same manner as in Examples 1 to 3, and the bending strength of each ceramic plate was measured in accordance with the method specified in JIS A5209. . Table 2 summarizes the results.
It was shown to.

[0067]

[Table 2] As is clear from the data in Table 2, the porosity is 0.4 or less,
The porcelain plate of the present invention manufactured using a green whose water absorption is adjusted to 30% or less has excellent bending strength, surface smoothness, warpage and deformation, and surface antifouling properties. Example 6 A porcelain plate was manufactured in the same manner as in Example 4 except that the slurry (A) in Example 4 was further made into a paper using a slurry in which 2 parts by weight of a cobalt oxide-based blue content was added. .

The surface of the obtained ceramic plate was dense and glowing blue, and was a suitable material as an interior material or an exterior material of a building. Example 7 Except that the slurry (A) in Example 4 was further mixed with 3 parts by weight of fine granite powder to produce a sheet-like molded body, and the sheet-like molded body was laminated and arranged on the surface. In the same manner as in Example 4, a ceramic plate having a five-layer structure was manufactured.

The surface of the obtained ceramic plate was dense and had a granite-like pattern, and could be used as it was as an interior material or exterior material of a building.

[0070]

As is clear from the above description, the ceramic plate of the present invention has a multilayer structure of sheet-like fired bodies having different softening temperatures. Therefore, a sheet-like fired body having a low softening temperature is disposed as a surface layer. By doing so, the degree of firing of the surface during firing is increased, so that the surface has a dense structure, and also has a smooth surface without corrugated uneven deformation, and at the same time, a ceramic plate with excellent impact resistance and strength characteristics can do. Also, in manufacturing, after laminating a required number of thin sheet-shaped molded bodies having different softening temperatures after firing, the laminated body is fired. For example, by changing the composition of each sheet-shaped molded body, each interlayer in the firing process is changed. By controlling the amount of thermal expansion of the ceramic sheet, the stress generated in the sheet-like fired body after firing can be controlled, whereby the strength characteristics of the entire ceramic plate can be enhanced and the entire warp and deformation can be suppressed.

Further, since the slurry which is the raw material of the sheet-like molded body contains an organic material having a glass transition point of 10 ° C. or less, the obtained sheet-like molded body is flexible. In addition, the respective sheet-like molded bodies can be satisfactorily bound to each other. Furthermore, in the method for manufacturing a ceramic plate according to the present invention, the state of lamination of the sheet-shaped molded bodies to be used can be changed arbitrarily, so that various manufacturing designs are possible and various needs can be met. For example, a desired design effect can be imparted by adding a coloring material to the sheet-like molded body of the surface layer or imparting various patterns.

The ceramic plate of the present invention can be used in a wide variety of applications, such as building exterior walls, interior materials, flooring, furniture top plates, counters, various interior materials, and civil engineering. The value is great.

Continuing from the front page (72) Inventor Norio Noda 1-1-1 Sonoyama, Otsu City, Shiga Prefecture Toray Industries, Inc. Shiga Plant (72) Inventor Shigeru Murata 1-2-4, Asahi Ono Asahi, Shiga-cho, Shiga-gun, Shiga Prefecture ( 72) Inventor Teruki Ueda 388 Nagahara, Yasu-cho, Yasu-gun, Shiga Prefecture (56) References JP-A-1-252561 (JP, A) JP-A-63-207610 (JP, A) JP-A-58-117801 ( JP, A) JP-A-58-20407 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B28B 1/52 B28B 3/02 C04B 33/13

Claims (13)

(57) [Claims] 1. A ceramic plate in which two or more sheet-like fired bodies mainly composed of a ceramic material are laminated, and at least two of the sheet-like fired bodies have different softening temperatures from each other. Ceramic plate characterized by the following. 2. The porcelain plate according to claim 1, wherein the difference in softening temperature in each of the sheet-like fired bodies is 10 ° C. or more. 3. The ceramic plate according to claim 1, wherein three or more sheet-like fired bodies are laminated. 4. The ceramic plate according to claim 1, wherein the thickness of each sheet-like fired body is 0.1 to 2 mm. 5. The ceramic plate according to claim 1, wherein at least the surface layer is formed of a sheet-like fired body having a relatively low softening temperature. 6. The ceramic plate according to claim 5, wherein a coloring material is added to said surface layer. 7. A sheet-like fired body having a lower softening temperature has a larger thermal expansion coefficient than a sheet-like fired body having a higher softening temperature, and the difference between the two coefficients of thermal expansion is 0.2 × 10 ^−6. ~ 2.0
The ceramic plate according to claim 1, which has a ^{density of 10-6} / C. 8. At least two kinds of slurries containing a ceramic material powder, a fiber material, and a thermoplastic organic material having a glass transition point of 10 ° C. or lower as essential components, and each of the slurries is formed into a sheet. When the compacts are fired, at least two types of slurries are prepared such that the respective softening temperatures are different, and at least two sheet-like compacts are separately formed from each of the slurries. The sheet-like molded body is laminated to at least 2
A method for producing a ceramic body, comprising forming a laminate having a layer structure, pressing and integrating the laminate, and then firing. 9. A ceramic plate according to claim 1
There was a building exterior material. 10. The porcelain plate according to claim 1,
Used interior materials for architecture. 11. The ceramic plate according to claim 1,
Used architectural floorboards. 12. The ceramic plate according to claim 1
Used furniture top plate. 13. The ceramic plate according to claim 1
Used indoor counter.