TW201638051A - Ceramic plate-shaped body and method for producing same - Google Patents

Abstract

This ceramic plate-shaped body (10) has a plate-shaped porous body site formed of ceramics. In plan view, the ceramic plate-shaped body (10) has a first region (21) having a first porosity and a second region (22) having a second porosity that is lower than the first porosity. The first region (21) and the second region (22) are made of the same ceramic material. It is preferred that, in plan view, the ceramic plate-shaped body has a center region, and a peripheral region that surrounds the center region and that includes the peripheral edges of the plate-shaped body. The center region comprises one or a plurality of the first regions (21), and the peripheral region comprise the second region (22).

Description

Ceramic plate body and manufacturing method thereof

The present invention relates to a ceramic plate-like body suitable for use as a positioner of a burned material and a method of manufacturing the same.

When firing an electronic component or glass made of ceramics, the burned material is generally placed on a positioner called a shelf or a pad to be fired. In this case, in the case where a large-sized burned object is placed on the positioner, or when a large number of burned objects are placed on the positioner, it is necessary to increase the position in the positioner. The mounting surface of the burnt material. However, if the size of the mounting surface is increased, a temperature difference is likely to occur in the central region and the peripheral region of the mounting surface. The temperature difference may cause warpage of the fired product or the like, which may affect the quality of the finished product. Therefore, it is desirable that no temperature difference occurs on the mounting surface.

In order to perform uniform heating during firing, Patent Document 1 discloses a porous ceramic positioner having excellent gas permeability and high thermal conductivity. The locator has the following cross-linking structure: ceramic fiber or whisker and ceramic particles selected from SiC, BN, AlN, BeO, MoSi ₂ , TiN, ZrB ₂ having an average particle diameter of 5 to 100 μm, and a heat-resistant inorganic binder The crosslinked structure between the combined fibers.

In the same manner as in Patent Document 1, in order to perform uniform heating during firing, Patent Document 2 discloses a method for producing a ceramic plate, which includes a molding step in which a ceramic powder is used and a powder is used to protect the powder. a shaped organic compound or a raw material of clay to form a molded product; a drying/firing step, after drying the shaped product, firing the dried shaped product at a temperature of 1300 to 1800 ° C; and a cutting step, It will burn the obtained The object is cut into a flat shape having a uniform thickness.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-251071

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-29462

However, even with the techniques disclosed in Patent Documents 1 and 2, it is difficult to reduce the temperature difference generated in the central portion and the peripheral portion of the positioner mounting surface to a satisfactory level. In particular, it is not easy to reduce the temperature difference during heating or cooling in the firing step, especially during sudden heating or quenching.

An object of the present invention is to provide a ceramic plate-like body which can be used as a positioner, which can eliminate various defects of the prior art described above.

The present invention provides a ceramic plate-like body having a portion including a ceramic plate-shaped porous body and having a first region and a second region in a plan view, wherein the first region has a first porosity and the second region has The porosity is lower than the second porosity of the first porosity, and the first region is the same ceramic material as the second region.

Moreover, the present invention provides a method for producing a ceramic plate-like body as a suitable method for producing the ceramic plate-like body, comprising the steps of: casting in a mold for casting having a concave portion complementary to a target ceramic plate-like body; a nesting member is disposed in the concave portion; a first slurry containing a ceramic raw material powder and a gelling agent is supplied into the concave portion to be gelated to form a first molded body; and the nesting member is released from the concave portion Then, the second slurry containing the ceramic raw material powder and the gelling agent is supplied into a mold release space formed by demolding the nesting member, and the first molded body and the first molded body are processed. The second slurry supplied in the demolding space After freezing, the frozen body is obtained; the frozen body is dried to obtain a dried body; thereafter, the dried body is fired, and the concentrations of the ceramic raw material powders used as the first and second pastes are different from each other. By.

10‧‧‧Ceramic plate

11‧‧‧ Body Department

11a‧‧‧1st

11b‧‧‧2nd

12‧‧‧ feet

21‧‧‧1st area

22‧‧‧2nd area

30‧‧‧ casting mold

31‧‧‧ bottom

32‧‧‧ side

33‧‧‧ core member

41‧‧‧1st slurry

41a‧‧‧1st formed body

42‧‧‧Second slurry

43‧‧‧Mold release space

44‧‧‧ dry body

S‧‧‧ recess

Fig. 1 is a perspective view showing an embodiment of a ceramic plate-like body of the present invention.

Figure 2 is a cross-sectional view taken along line II-II of Figure 1.

3(a) to 3(c) are process diagrams showing a suitable manufacturing method of the ceramic plate-like body shown in Fig. 1.

4(a) to 4(d) are process diagrams showing a suitable manufacturing method of the ceramic plate-like body shown in Fig. 1 subsequent to Fig. 3(c).

Fig. 5 is a scanning electron microscope image of a central region of the ceramic plate-like body obtained in Example 1.

Fig. 6 is a scanning electron microscope image of a peripheral region in the ceramic plate-like body obtained in Example 1.

Fig. 7 is a view of a temperature recorder when the ceramic plate-like body obtained in Example 1 was heated and then quenched.

Fig. 8 is a view of a temperature recorder when the ceramic plate-like body obtained in Comparative Example 2 was heated and then quenched.

Hereinafter, the present invention will be described with reference to the drawings in accordance with preferred embodiments thereof. In Fig. 1, an embodiment of a ceramic plate-like body of the present invention is shown. Figure 2 is a cross-sectional view taken along line II-II of Figure 1. The ceramic plate-like body 10 shown in the figures is used as a positioner when the burned material is fired. The ceramic plate-like body 10 has a plate-like main body portion 11. The body portion 11 includes a porous body including ceramic. The main body portion 11 has a first surface 11a and a second surface 11b opposed thereto. this The body 11 has a rectangular shape in plan view. However, the shape of the main body portion 11 in a plan view is not limited to a rectangular shape, and various shapes can be adopted depending on the shape and number of the burned objects. Regardless of the shape of the body portion 11 in plan view, the thickness of the body portion 11 is preferably the same at any position.

The ceramic plate-like body 10 has a leg portion 12 in addition to the body portion 11. The leg portion 12 is provided at a corner portion of the body portion 11. As described above, the body portion 11 has a rectangular shape in plan view, and the leg portions 12 are located at the four corners of the body portion 11. The leg portion 12 is suspended from the second surface 11b of the body portion. The leg portion 12 is formed integrally with the body portion 11. Further, the leg portion 12 is formed of the same ceramic material as the body portion 11. However, the foot portion 12 need not be a porous body.

When the ceramic plate-like body 10 is used, that is, when the fired material is fired, the first surface 11a of the main body portion 11 serves as a mounting surface of the fired material. The first surface 11a is a flat surface. That is, the first surface 11a is a flat surface and does not become a curved surface. Further, the first surface 11a is a smooth surface. That is, the first surface 11a is smooth, and there is no convex portion or concave portion. When the first surface 11a is flat and smooth, the burned material can be stably placed on the first surface 11a during firing, and uniform burning can be performed. to make. On the other hand, regarding the second surface 11b, the surface shape thereof is not particularly required.

As described above, the main body portion 11 includes a porous body, and as a result, the main body portion 11 has two regions having different porosity. Specifically, the main body portion 11 has a first region and a second porosity in a plan view, the first region 21 has a first porosity, and the second region 22 has a porosity which is lower than the first porosity. 2 porosity. When the first region 21 and the second region 22 are formed by the method described later, the porosity in the first region 21 and the porosity in the second region 22 change stepwise. However, the boundary between the first region 21 and the second region 22 may not be clear, and the porosity may be gradually decreased from the first region 21 to the second region 22. When the porosity is gradually decreased from the first region 21 to the second region 22, the boundary between the two regions is a position having an average value of the porosity of the first region 21 and the porosity of the second region. The first region 21 and the second region 22 are preferably formed integrally. The term "integrally formed" does not mean that the first region 21 and the second region 22 are joined by some bonding method, but that the two regions 21, 22 are connected as ceramics. Continued structure. The ceramic plate-like body 10 in which the first region 21 and the second region 22 are integrally formed can be manufactured according to a suitable production method described later, and in the case of other manufacturing methods, the two regions 21 and 22 are sometimes obtained. A ceramic plate body 10 integrally formed. When the first region 21 and the second region 22 are integrally formed, the temperature difference between the central region and the peripheral region of the main body portion 10 can be further reduced during heating and/or cooling of the ceramic plate-like body 10, Preferably.

The main body portion 11 has a central region in a plan view and a peripheral region that surrounds the central region and includes a region around the peripheral end of the main body portion 11. The central region includes one first region 21. Moreover, the peripheral region includes the second region 22. The first region 21 located in the central region has a rectangular shape substantially similar to the shape of the main body portion 11 in a plan view of the main body portion 11. However, the shape of the first region 21 in plan view does not need to be a shape similar to the shape of the main body portion 11 in plan view. Further, the shape of the first region 21 in plan view does not need to be rectangular. For example, the shape of the first region 21 in plan view may be a polygon other than a circle or a rectangle. From the viewpoint of minimizing the temperature difference between the central region and the peripheral region, it is preferable to intersect the normal line drawn at an arbitrary position on the periphery of the first region 21 to the peripheral end of the body portion 11 in a plan view. The length is the same anywhere on the circumference. For example, it is preferable that the first region 21 is a circle, and the second region 22 is a ring having the same inner diameter as the circle, and the circle of the first region 21 is concentric with the ring of the second region 22. Further, it is preferable that the normal to the arbitrary position on the peripheral edge of the first region 21 in the plan view is different from the circumferential end of the main body portion 11 at any two or more positions on the peripheral edge. The ratio of the ratio L _max /L _min of the length L _max to the shortest length L _min is 8 or less, particularly 4 or less.

The first region 21 preferably has a constant porosity, that is, a first porosity, over the entire thickness direction and the in-plane direction. On the other hand, the second region 22 preferably has a constant porosity, that is, a second porosity, over the entire thickness direction and the in-plane direction.

The first region 21 and the second region 22 contain the same ceramic material. By the two regions 21, 22 containing the same ceramic material, one of the two regions 21, 22 has a higher body feel, maintaining the strength Advantages in terms of heat transfer. In particular, when the two regions 21 and 22 are integrally formed as described above, if the two regions 21 and 22 include the same ceramic material, the integrated feeling is further improved. As a result, the temperature difference between the central region and the peripheral region of the main body portion 10 can be further reduced during heating and/or cooling of the ceramic plate-like body 10.

When the ceramic plate-like body 10 of the present embodiment having the above-described configuration is used as a positioner for firing a burned material, it can be positioned earlier than during heating and cooling during the firing process. The device further reduces the temperature difference between the central region and the peripheral region of the body portion 11. This is because the first region 21 having a high porosity has a smaller heat capacity than the second region 22 which is a region having a low porosity. Therefore, the first region 21 having a small heat capacity is disposed in the central region, and The second region 22 having a large heat capacity is disposed in a peripheral region surrounding the central region, and can easily heat the central region that is not easily heated when heated, and can easily remove the central region that is not easily cooled during cooling. Cooling, therefore, as a result, the temperature difference between the central region and the peripheral region during heating and cooling can be reduced.

In particular, as exemplified in Examples 1 and 2 to be described later, the ceramic plate-like body 10 is preferably cooled such that the temperature in the central portion is lower than the temperature in the peripheral region. The reason is as follows. In the case where the ceramic plate-like body 10 is used as, for example, a positioner of a burned material, the burned material is often placed in the central portion of the positioner. When the film is fired in such a mounted state and then cooled, the total heat capacity of the central region and the heat capacity of the fired product are cooled in the central portion of the positioner. Therefore, if the temperature in the central region is lower than the temperature in the peripheral region, the heat capacity of the burned material can be offset by the heat capacity in the peripheral region of the retainer, so that the cooling can be quickly performed.

The porosity of the first region 21 is preferably 50% or more and 99% or less, more preferably 60% or more and 90% or less, and still more preferably 70% or more, from the viewpoint that the above advantageous effects are more remarkable. 90% or less. On the other hand, the porosity of the second region 22 is preferably 0% or more and 70% or less, more preferably 0% or more and 60% or less, more preferably less than the porosity of the first region 21. It is 0% or more and 50% or less.

The porosity is a physical property value defined by the apparent porosity determined by the Archimedes method. The porosity of the first region 21 and the second region 22 of the main body portion 11 is measured by the following method. The main body portion 11 is processed by a cutter, and only the first region 21 and the second region 22 are taken out, respectively, and the apparent porosity is measured in accordance with JIS R1634 (vacuum method). In the ceramic plate-like body 10 manufactured by the manufacturing method described later, since the pores are almost entirely open pores, the open porosity is directly a value of the porosity.

From the viewpoint of further reducing the temperature difference between the central region and the peripheral region during heating and cooling, the ratio of the sum S1 of the areas of the first regions 21 in plan view to the area S _T of the body portion 11 in plan view It is preferably 20% or more and 95% or less, more preferably 40% or more and 85% or less, still more preferably 50% or more and 70% or less. From the same viewpoint, the ratio of the area S2 of the second region 22 in a plan view is preferably 5% or more and 80% or less, and more preferably 15% or more, with respect to the area S _T of the main body portion 11 in plan view. And 60% or less, more preferably 30% or more and 50% or less.

In the ceramic plate-like body 10 of the embodiment shown in FIG. 1, the first region 21 is formed in only one central portion of the main body portion 11, and two or more of the central portions of the main body portion 11 may be formed instead. The first area 21 is. In this case, the two or more first regions 21 are divided by a third region (not shown). The third region has a region lower than the first region 21 but higher than the porosity of the second region 22. The third region may be divided into the first region 21 and the second region 22 in addition to the division between the adjacent first regions 21.

As the ceramic material constituting the ceramic plate-like body 10, various materials can be used. For example, alumina, tantalum carbide, niobium nitride, zirconium oxide, mullite, magnesium oxide, titanium diboride or the like can be cited.

Next, a suitable manufacturing method of the ceramic plate-like body 10 shown in Figs. 1 and 2 will be described with reference to Figs. 3 and 4 . First, as shown in Fig. 3 (a), a casting mold 30 is prepared. The casting mold 30 has a bottom surface 31 having a substantially rectangular shape in plan view, and four side surfaces 32 rising from the periphery of the bottom surface 31, and the upper surface is open. Moreover, the bottom surface 31 and the side surface 32 are divided and formed upward. The square is open to the recess S. This concave portion S has a shape complementary to the target ceramic plate-like body 10.

The core member 33 is placed on the bottom surface 31 in the recess S of the casting mold 30 as shown in Fig. 3(b). The core member 33 has a rectangular parallelepiped shape. The core member 33 has the same shape as that of the first region 21 of the target ceramic plate-like body 10 in plan view. The placement position of the core member 33 on the bottom surface 31 is made to coincide with the predetermined formation region of the first region 21 in the target ceramic plate member 10.

In the state shown in FIG. 3(b), as shown in FIG. 3(c), the first slurry 41 is supplied into the concave portion S of the casting mold 30. The first slurry 41 contains a ceramic raw material powder and a gelling agent as a medium. Further, the first slurry 41 contains water or a water-soluble organic solvent as a medium.

The ceramic raw material powder contained in the first slurry 41 is a raw material of the ceramic material constituting the second region 22 of the target ceramic plate-like body 10. The particle diameter of the ceramic raw material powder is represented by a volume cumulative particle diameter D _{50 of 50} % by volume of the cumulative volume obtained by the laser diffraction scattering particle size distribution measurement method, preferably 0.01 μm or more and 100 μm or less, and further preferably 0.05 μm. The above is 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less.

The concentration of the ceramic raw material powder contained in the first slurry 41 is related to the porosity of the second region 22 in the target ceramic plate-like body 10. Specifically, the higher the concentration of the ceramic raw material powder contained in the first slurry, the lower the porosity of the second region 22 is. From this point of view, the concentration of the ceramic raw material powder contained in the first slurry 41 is preferably 17 parts by volume or more and 150 parts by volume or less, and more preferably 25 parts by volume or more and 150 parts by volume with respect to 100 parts by volume of the medium. The remainder is more preferably 33 parts by volume or more and 150 parts by volume or less.

The type and concentration of the gelling agent contained in the first slurry 41 are related to the degree of gelation of the first slurry 41 to be described later. From this viewpoint, the concentration of the gelling agent contained in the first slurry 41 is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 7 parts by mass based on 100 parts by mass of the medium. The amount is preferably 1 part by mass or more and 4 parts by mass or less.

The gelling agent is used as a lyophilized body obtained by freeze-drying described later. A binder in which particles of the ceramic raw material powder are combined with each other. In order to achieve the object, an N-alkyl guanamine polymer, an N-isopropyl acrylamide polymer, a sulfomethyl acrylamide polymer, and N-dimethylaminopropyl group can be used. Acrylamide polymer, polyalkyl acrylamide polymer, alginic acid, sodium alginate, ammonium alginate, polyethylenimine, cellulose derivatives, polyacrylate, polyethylene glycol , polyethylene oxide, polyvinyl alcohol, polyvinyl pyrrolidone, carboxyvinyl polymer, starch, gelatin, agar, pectin, glucomannan, Sanxian gum, locust bean gum, carrageenan, ancient Gum, gellan gum, lignosulfonate, polypropylene decylamine, polyvinyl ester, isobutylene-maleic anhydride copolymer, vinyl acetate, epoxy resin, phenol resin and urethane resin, etc. As a gelling agent. These gelling agents may be used alone or in combination of two or more.

The weight average molecular weight of the gelling agent is preferably 500 or more and 2,000,000 or less, more preferably 2,000 or more and 1.5,000,000 or less, and still more preferably 4,000 or more and 1,000,000 or less.

In the first slurry, other components may be blended in addition to the above components. For example, a dispersing agent for dispersing the ceramic raw material powder in the medium can be provided. As the dispersing agent, for example, a polycarboxylic acid ammonium salt, a polyacrylic acid ammonium salt, a polyethylenimine or the like can be used. The blending amount of the dispersing agent is preferably 0.5 parts by mass or more and 3 parts by mass or less based on 100 parts by mass of the ceramic raw material powder.

After the first slurry 41 is supplied into the concave portion S of the casting mold 30, the slurry is gelated. In order to gelatinize it, for example, it is only necessary to cool the slurry. The cooling temperature can be set, for example, to 1 ° C or more and 12 ° C or less. By the gelation of the first slurry, the slurry obtains shape retention property, and the first molded body 41a is obtained.

Next, as shown in FIG. 4(a), the core member 33 surrounded by the first molded body 41a is released. Since the first molded body 41a has shape retaining properties as described above, even if the core member 33 is released from the mold, the shape of the first molded body 41a does not change. As a result, the mold release space 43 is formed in the central region of the first molded body 41a by demolding. The demolding space 43 becomes a through hole, and At the bottom, the bottom surface 31 of the casting mold 30 is exposed.

In the demolding space 43 formed by demolding the core member 33, the second slurry 42 is supplied as shown in Fig. 4(b). The second slurry 42 contains a ceramic raw material powder and a gelling agent as a medium. Further, the second slurry 42 contains water or a water-soluble organic solvent as a medium.

The ceramic raw material powder contained in the second slurry 42 is a raw material of the ceramic material constituting the first region 21 of the target ceramic plate-like body 10. This ceramic raw material powder is the same type as the ceramic raw material powder contained in the first slurry 41. The particle diameter of the ceramic raw material powder contained in the second slurry 42 may be the same as or different from the particle diameter of the ceramic raw material powder contained in the first slurry 41. The particle diameter of the ceramic raw material powder contained in the second slurry 42 is represented by a volume cumulative particle diameter D ₅₀ of 50% by volume of the cumulative volume obtained by the laser diffraction scattering particle size distribution measurement method, and preferably 0.1 μm or more. Further, it is 100 μm or less, more preferably 0.05 μm or more and 10 μm or less, and still more preferably 0.1 μm or more and 1 μm or less.

The concentration of the ceramic raw material powder contained in the second slurry 42 is related to the porosity of the first region 21 in the target ceramic plate-like body 10. Specifically, the lower the concentration of the ceramic raw material powder contained in the second slurry 42 is, the higher the porosity of the first region 21 is. In the ceramic plate-like body 10 which is the object of the present manufacturing method, since the porosity is different between the first region 21 and the second region 22, the concentration of the ceramic raw material powder contained in the second slurry 42 is the same as The concentration of the ceramic raw material powder contained in the slurry 41 is different from each other, and the target first region 21 and the second region 22 can be favorably formed from the beginning to the end. From this point of view, the concentration of the ceramic raw material powder contained in the second slurry 42 is preferably 1 based on the concentration of the ceramic raw material powder contained in the first slurry 41, based on 100 parts by volume of the medium. The volume is at least 33 parts by volume, more preferably 1 part by volume or more and 25 parts by volume or less, more preferably 1 part by volume or more and 18 parts by volume or less.

The gelling agent contained in the second slurry 42 may be the same type as the gelling agent contained in the first slurry 41, or may be different types. The concentration of the gelling agent contained in the second slurry 42 is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 7 parts by mass or less, more preferably 100 parts by mass or less. 1 part by mass or more and 4 parts by mass or less.

The amount of the second slurry 42 supplied into the above-mentioned mold release space 43 is preferably set such that the liquid surface of the second slurry 42 is at the same position as the upper surface of the first molded body 41a. By setting in this way, the first surface 11a of the main body portion 11 in the obtained ceramic plate-like body 10 can be made flat.

In the state in which the second slurry 42 is filled in the mold release space 43 of the first molded body 41a, the freezing step is performed. First, the second slurry 42 may be gelated by cooling before, or the state of the slurry may be maintained without gelation, and the freeze-drying step may be performed. By performing the freezing step, freezing is performed from one direction, and ice crystals are grown to form an alignment structure of the ceramic raw material powder in the first molded body 41a and the second slurry 42. That is, the rearrangement of the ceramic raw material powder occurs. A well-known cooling device can be utilized for freezing. Specifically, a method of bringing the lower surface of the casting mold 30 into contact with a solid such as a cooled metal plate, or a method of immersing it in the cooled liquid together with the casting mold 30, or the like can be used. Further, for example, an ethanol cooling device may be used which circulates ethanol cooled to a specific temperature in such a manner as to flow from one side to the other side without being deposited or fluctuated near the liquid surface of the ethanol, thereby Keep the temperature near the liquid level constant. An ethanol cooling device having such a configuration can be used, and the bottom surface of the casting mold 30 is brought into contact with or immersed in the liquid surface of the cooled ethanol, and is frozen in one direction from the bottom upward. Thereby, the ceramic plate-like body 10 with less uneven pore diameter can be produced.

The freezing temperature in the freezing step is not limited as long as the water in the gel or the slurry can be frozen to form ice. Further, depending on the type of the gelling agent, there is a case where it is not frozen at -10 ° C or higher due to the interaction with water, so it is preferably a freezing temperature of -10 ° C or lower. For example, it is preferable to use the above-described ethanol type refrigerator to immerse the casting mold 30 in ethanol cooled to -15 ° C and freeze it in one direction from the bottom.

Next, as shown in FIG. 4(d), the frozen body produced by the freezing is taken out from the casting mold 30 and dried. In the drying step, it is preferred to use a drying method in which the ice is gradually replaced with pores while suppressing the difference in drying speed between the inside and the outside of the frozen body. This prevents cracking. Specifically, the ice can be replaced with pores by freeze-drying the frozen body or immersing in a water-soluble organic solvent or a water-soluble organic solvent aqueous solution and air drying. For example, when the frozen body is immersed in a water-soluble organic solvent or a water-soluble organic solvent aqueous solution, the ice in the frozen body is melted and mixed with the water-soluble organic solvent. By performing this operation one or more times, first, the portion of the frozen body which is ice is replaced with a water-soluble organic solvent. Thereafter, when the frozen body in which the inside of the frozen body is replaced with the water-soluble organic solvent is dried in the air or under reduced pressure, the portion of the ice is replaced with the pores in the freezing step.

In the drying step using a water-soluble organic solvent, as the water-soluble organic solvent, those which do not corrode the gelling agent and have a higher volatility than water are used. Specific examples thereof include methanol, ethanol, isopropanol, acetone, ethyl acetate, and the like, but are not limited thereto. The pores are formed in the frozen body as part of the ice by using the water-soluble organic solvent alone or in combination with a plurality of types of drying.

Next, the drying process 44 which is produced by drying is subjected to a baking step. By this baking, the target ceramic plate-like body 10 can be obtained. The firing can usually be carried out under the atmosphere. The firing temperature may be selected according to the type of the ceramic raw material powder. The same applies to the firing temperature.

By the above method, the target ceramic plate-like body 10 can be obtained. The ceramic plate-like body 10 is suitably used as a locating device for firing a ceramic product such as a shelf or a backing plate as described above, and can also be used as a kiln tool other than a locator, such as a raft or a beam. Furthermore, it can also be used for applications other than kiln tools, such as various jigs and various structural materials.

The present invention has been described above based on the preferred embodiments thereof, but the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the porosity of the central portion of the plate-like main portion 11 is higher than the porosity of the peripheral region, but the arrangement of the first region 21 having a high porosity and the second region 22 having a low porosity is disposed. The location is not limited to it. For example, depending on the specific use of the ceramic plate-like body of the present invention, the first region 21 having a high porosity may be disposed in the peripheral region of the plate-like body, and the second region 22 having a low porosity may be disposed in a plate shape. Among the bodies Central area. Alternatively, the first region 21 having a high porosity and the second region 22 having a low porosity may be alternately arranged in a stripe shape, thereby being arranged in a checkerboard pattern.

Example

The invention is illustrated in more detail below by way of examples. However, the scope of the invention is not limited by the embodiment. Unless otherwise stated, “parts” means “parts by mass”.

[Example 1]

The ceramic plate-like body 10 shown in Figs. 1 and 2 was produced in accordance with the method shown in Figs. 3 and 4 . Water, alumina particles, and a dispersing agent were mixed for 1 minute using a mixing stirrer, and an aqueous solution obtained by dissolving gelatin as a gelling agent in hot water was prepared, and the both were mixed, and the 1st slurry 41 was obtained. So as to obtain the first slurry 41 containing a D ₅₀ of the alumina-based particles of 0.5μm, and further containing gelatin and an aqueous slurry of the dispersant. The composition of the slurry is shown in Table 1 below. The amount of the alumina particles was 43 parts by volume with respect to 100 parts by volume of the water in the slurry.

On the other hand, the water, the alumina particles, and the dispersing agent were mixed for 1 minute using a mixing mixer, and an aqueous solution obtained by dissolving gelatin as a gelling agent in hot water was prepared, and the two were mixed to obtain a second slurry. Material 42. The first slurry 41 thus obtained contains alumina particles having a D ₅₀ of 0.5 μm, and further contains a water slurry of gelatin and a dispersant. The composition of the slurry is shown in Table 1 below. The amount of the alumina particles was 11 parts by volume with respect to 100 parts by volume of the water in the slurry.

As the casting mold 30, a person having a square shape in plan view is used. The size of the casting mold 30 in plan view is 130 mm × 130 mm. A rectangular parallelepiped core member 33 is disposed in a central portion of the concave portion S of the casting mold 30, and the first slurry 41 is supplied in this state. The core member 33 has a rectangular shape of 96.4 mm × 96.4 mm in plan view. The supply amount of the first slurry 41 is set such that the depth in the concave portion S is 5 mm. The casting mold 30 is placed in a refrigerator, and the first slurry 41 is cooled and gelled to obtain a first molded body 41a.

Next, the core member 33 is released from the mold, and the second slurry 42 is supplied into the mold release space 43 which is produced by demolding. The supply amount of the second slurry 42 is set to the upper surface of the first molded body 41a. The amount is the same as the liquid level of the second slurry 42. In this state, the casting mold 30 was frozen at -10 ° C using ethanol. The obtained frozen body was taken out from the mold 30 for casting, and dried by a vacuum freeze-drying apparatus (manufactured by Tokyo Science Instruments Co., Ltd., FDU-1100) for 24 hours.

The thus obtained dried body was fired at 1600 ° C for 7 hours. The fired product was subjected to double-side grinding so that the thickness of the body portion 11 was 2 mm. Thereby, the target ceramic plate-like body 10 is obtained. The central portion of the main body portion 11 in the ceramic plate-like body 10 has a porosity of 80%, and the peripheral portion has a porosity of 25%. The main body portion 11 includes a first region 21 and a second region 22 . Table 2 shows the ratio of the sum S1 of the areas of the first regions 21 in the plan view with respect to the area S _T of the main body portion 11. A scanning electron micrograph of the central region of the ceramic plate-like body of Example 1 is shown in Fig. 5, and a scanning electron micrograph of the peripheral region of the ceramic plate-like body of Example 1 is shown in Fig. 6. By comparison of these scanning electron microscope photographs, it was also confirmed that the void portion of the central region was larger than the peripheral region, and it was found that the porosity was higher than that of the peripheral region.

[Embodiment 2]

In the first embodiment, a rectangular shape having a shape of 111.7 mm × 111.7 mm in plan view is used as the core member 33. Otherwise, the ceramic plate-like body 10 was obtained in the same manner as in the first embodiment. The main body portion 11 includes a first region 21 and a second region 22 . The ratio of the sum S1 of the areas of the first regions 21 in the plan view with respect to the area S _T of the body portion 11 is as shown in Table 2.

[Example 3]

In the first embodiment, the components shown in the following Table 1 were used as the first and second slurry. Further, a rectangular member having a shape of 124.5 mm × 124.5 mm in plan view is used as the core member 33. Otherwise, the ceramic plate-like body 10 was obtained in the same manner as in the first embodiment. The main body portion 11 includes a first region 21 and a second region 22 . The ratio of the sum S1 of the areas of the first regions 21 in the plan view with respect to the area S _T of the body portion 11 is as shown in Table 2. The amount of the alumina particles was 25 parts by volume with respect to 100 parts by volume of the water in the slurry of the first. The amount of the alumina particles was 11 parts by volume with respect to 100 parts by volume of the water in the second slurry.

[Comparative Example 1]

In the first embodiment, only the second slurry 42 was used, and the core member 33 was not used. A ceramic plate-like body was obtained in the same manner as in Example 1 except the above. The porosity of the body portion 11 in the ceramic plate-like body was 80%.

[Comparative Example 2]

40 parts of electrothermally smelted alumina, 30 parts of electrothermal smelting mullite, 30 parts of low alkali calcined alumina, an appropriate amount of organic binder and a liquid binder were mixed to obtain a mixture. The mixture was kneaded, dried, and pressure molded to obtain a molded body. This molded body was air-fired at 1750 ° C to obtain a refractory plate-like body. The porosity of the body portion 11 in the refractory plate-like body was 17%. The body portion 11 has a thickness of 5 mm.

[Evaluation]

The ceramic plate-like bodies obtained in the examples and the comparative examples were heated. The heating was performed such that the temperature in the central portion of the plate-shaped body was 500 °C. The ceramic plate body heated to this temperature is taken out from the heating furnace to the atmosphere. Quenching. The time at which the temperature of the central portion of the plate-shaped body was cooled to about 400 ° C was measured. Further, the temperature at the central portion of the plate-like body was measured to be the lowest temperature in the peripheral portion of the plate-like body at a temperature of about 400 °C. The measurement of the temperature was carried out using a temperature recorder (manufactured by Chino Co., Ltd., CPA-640A). The results are shown in Table 2 below. Moreover, as a photograph of the appearance of coloring the measured temperature distribution by a temperature recorder, The photographer of Example 1 is shown in Fig. 7, and the subject of Comparative Example 2 is shown in Fig. 8.

As is apparent from the results shown in Table 2, it was found that the ceramic plate-like body 10 obtained in Example 1 was different from the ceramic plate-like body of the comparative example because of the difference in porosity between the central region and the peripheral region. The temperature difference between the area and the peripheral area becomes smaller. Also, it is known that it is cooled in a short time. In particular, in Examples 1 and 2, when the temperature in the central region is lower than the peripheral region and the fired body is placed in the central region and fired, the heat is easily offset in the peripheral region and the central region. Further, as shown by a comparison between FIG. 7 and FIG. 8, it is known that the temperature of the peripheral region in Comparative Example 2 of FIG. 8 is lower than that of the central region, and the temperature difference is large. In contrast, in Embodiment 1 of FIG. The temperature at the peripheral portion is slightly higher than the temperature in the central portion, and the temperature difference is small.

[Industry use possibility]

According to the present invention, the plate-like body contains ceramics, so that the plate-shaped body can be used in a harsh environment, and the plate-like body can be used in a harsh environment because the porosity of a part of the plate-shaped body is higher or lower than that of other parts. The advantage. In particular, according to the present invention, there is provided a ceramic plate-like body which is less likely to cause a temperature difference in a central region and a peripheral region during heating and cooling, particularly during rapid heating and quenching.

10‧‧‧Ceramic plate

11‧‧‧ Body Department

11a‧‧‧1st

11b‧‧‧2nd

12‧‧‧ feet

21‧‧‧1st area

22‧‧‧2nd area

Claims (8)

A ceramic plate-like body having a portion including a ceramic plate-shaped porous body and having a first region and a second region in a plan view, wherein the first region has a first porosity and the second region has a low porosity In the second porosity of the first porosity, the first region and the second region are the same ceramic material. The ceramic plate-like body of claim 1, wherein the first region and the second region are formed integrally. The ceramic plate-like body of claim 1, which has a central region in plan view and a peripheral region surrounding the central region and including a peripheral end of the plate-like body, wherein the central region includes one or more first regions. In the area, the peripheral area includes the second area. The ceramic plate-like body according to claim 2, wherein the central region includes one first region, and the first region is surrounded by the peripheral region including the second region. The ceramic plate-like body according to claim 1, wherein the porosity of the first region is 50% or more and 99% or less, and the porosity of the second region is lower than the porosity of the first region, and is 0% or more. And 70% or less. The ceramic plate-like body of claim 1, wherein the ratio of the total area of the first region in a plan view is 20% or more and 95% or less with respect to the area of the plate-like body, and the area of the second region in plan view The ratio is 5% or more and 80% or less with respect to the area of the above-mentioned plate-shaped body. The ceramic plate-like body of claim 1, which is used as a locator for firing a ceramic article. A method for producing a ceramic plate-like body, which is the method for producing a ceramic plate-like body according to claim 1, and comprising the steps of: casting a mold having a concave portion complementary to a target ceramic plate-like body; a nesting member is disposed in the concave portion; a first slurry containing a ceramic raw material powder and a gelling agent is supplied into the concave portion to be gelated to form a first molded body; and the nesting member is formed from the concave portion After demolding, the second slurry containing the ceramic raw material powder and the gelling agent is supplied into a mold release space formed by demolding the nesting member; the first molded body is formed, and the first molded body is formed. The second slurry supplied in the demolding space of the body is frozen to obtain a frozen body; the frozen body is dried to obtain a dried body; thereafter, the dried body is fired, and the first and second pastes are used as the first and second pastes. The concentration of the above-mentioned ceramic raw material powders contained in the same is different from each other.