JP2011046002A - Method for manufacturing ceramic molded body product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a ceramic molded body with excellent flatness, in a method for manufacturing a thin-plate-like ceramic molded body by a gel cast method using a mold formed with an opening communicated with a molding space on its upper flat face. <P>SOLUTION: Ceramic slurry is introduced through the opening Pin of the mold 20 into the molding space Q until the ceramic slurry is raised upward from the upper face of the mold 20. Then, a squeegee is moved along the upper face of the mold 20 to remove part of the ceramic slurry which is raised upward from the upper face of the mold 20. Then, the opening Pin is closed with a lid member. In this state, the slurry is hardened by gelling reaction to obtain a molded body before drying. The molded product before drying is taken out of the mold 20, and the taken-out molded body before drying is sandwiched between two porous filters. The molded product before drying is dried in this state to obtain the ceramic molded product (before baking). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a ceramic molded body (also referred to as “ceramic green molded body”) before firing.

  Conventionally, as one method for producing a ceramic molded body (before firing), a ceramic slurry containing ceramic powder, a dispersion medium, and a gelling agent is formed into a molding space of a mold (a space for filling the slurry and molding it). There is a method in which a ceramic molded body is obtained by putting the ceramic slurry into a space having the same shape as the desired ceramic molded body, and curing and drying the ceramic slurry (see, for example, Patent Document 1). This method is called a so-called gel casting method. Hereinafter, the ceramic slurry may be simply referred to as “slurry”.

  In the gel cast method, the curing of the slurry is achieved mainly by a gelation reaction. In particular, when a urethane reaction is used as the gelation reaction, cross-linking occurs between adjacent urethane resin molecules so as to connect the urethane groups present in each urethane resin molecule. By this crosslinking, a strong network is formed between the urethane resin molecules. As a result, the slurry is cured. Further, the drying of the slurry is achieved mainly by volatilizing and removing the dispersion medium (solvent) component in the slurry. Hereinafter, the curing of the slurry by the gelation reaction may be simply referred to as “slurry curing”, and the drying of the slurry by the volatilization removal of the dispersion medium component may be simply referred to as “slurry drying”.

WO 2004/035281

  In the Japanese Patent Application No. 2008-256694, the present applicant uses, as a molding die, a type in which an opening (hole for introducing slurry) leading to the molding space is formed on the plane of the upper surface thereof, It has already been proposed to produce a ceramic molded body by a gel cast method. Hereinafter, in this case, the case where a thin plate-like ceramic molded body is manufactured will be considered.

  In this case, the slurry is put into the molding space of the mold through the opening exposed upward. Thereafter, the slurry filled in the molding space is subjected to a curing / drying step with the opening exposed upward. In this curing / drying step, volatilization of the dispersion medium component of the slurry is likely to occur due to the opening being exposed upward. Accordingly, the curing of the slurry and the drying of the slurry proceed simultaneously at their natural (desired) traveling speed without providing a special temporal order.

  For this reason, the progress of the curing of the slurry and the progress of the drying of the slurry can vary depending on the position in the molding space. Here, the ceramic molded body can shrink either by hardening of the slurry or by drying of the slurry. Generally, the degree of shrinkage due to drying of the slurry is greater than the degree of shrinkage due to hardening of the slurry. As described above, when the slurry is subjected to the curing / drying process with the opening exposed upward as described above, the degree of shrinkage of the thin plate-shaped ceramic molded body may vary depending on the position of the ceramic molded body. As a result, the amount of shrinkage in the thickness direction of the thin plate-shaped ceramic molded body may vary depending on the position of the ceramic molded body. That is, the variation in thickness of the thin plate-like ceramic molded body tends to be relatively large.

  In addition, the slurry is dried while the slurry is filled in the molding space. Accordingly, the volatilization progress rate of the dispersion medium component from the upper surface of the thin plate-shaped ceramic molded body is larger than the volatilization progress rate of the dispersion medium component from the lower surface. In other words, a difference in the degree of progress of drying may occur between the upper surface side and the lower surface side of the thin plate-shaped ceramic molded body. As a result, the warp (swell) of the thin plate-like ceramic molded body tends to be relatively large.

  As described above, when the slurry is subjected to the curing / drying process with the opening exposed upward, the thickness variation and warpage (swell) are likely to be relatively large with respect to the thin plate-like ceramic molded body. That is, there is room for slight improvement in terms of improving the flatness of the thin plate-like ceramic molded body.

  Therefore, an object of the present invention is to provide a flat ceramic mold by a gel casting method using a mold in which an opening leading to a molding space is formed on the plane of the upper surface as a molding die. An object of the present invention is to provide an excellent ceramic molded body.

  In order to achieve the above object, a method for producing a thin plate-like ceramic molded body (before firing) according to the present invention includes a step of feeding the ceramic slurry into the molding space of the molding die through the opening of the molding die. The lid member having a flat surface on the lower surface is placed on the mold, thereby closing the opening of the mold with the lid member, and the opening of the mold is blocked with the lid member. In the state, by curing the ceramic slurry filled in the molding space by a gelation reaction, a curing step of obtaining a thin plate-shaped pre-drying molded body, a lid removing step of removing the lid member from the molding die, In the state where the opening of the mold is exposed and the molded body before drying is accommodated in the molding space, or in the state where the molding mold is further removed from the molded body before drying, the molding before drying By drying the includes a drying step of obtaining the ceramic molded body.

  Here, in the manufactured thin plate-like ceramic molded body, at least the upper surface is constituted by a single plane. That is, both the upper and lower surfaces may be constituted by a single plane, or only the upper surface is constituted by a single plane, and the lower surface is provided with a concave portion (one or two or more places on the single plane). Grooves, depressions, etc.) may be formed.

  Moreover, it is preferable to use what contains the components (for example, isocyanate, polyol, etc.) which generate | occur | produce the urethane reaction as a gelling reaction as said slurry. In this case, the slurry may be described as containing ceramic powder, isocyanate, polyol, solvent, and (a urethane resin as a binder generated by a urethane reaction).

  According to the above configuration, in the charging step, the slurry can be continuously charged until a part of the slurry charged from the opening of the mold overflows from the opening and rises upward from the upper surface (plane) of the mold. Next, in the closing step, the lid member is placed on the mold, so that the opening is closed with the lid member. At this time, an external force downward from above may be applied to the lid member.

  The portion of the slurry that swells upward from the upper surface of the mold is pushed downward on the lower surface (planar surface) of the lid member by the weight of the lid member or in addition to the downward external force applied to the lid member from above. It will be crushed. This crushing is continued until the position in the height direction (vertical direction) of the lower surface (plane) of the lid member substantially coincides with the position in the height direction of the opening surface of the molding die (upper surface of the molding die). As a result, the portion of the slurry that swells upward from the upper surface of the mold is filled into the molding space or removed to the outside through a gap between the upper surface of the mold and the lower surface of the lid member. Is done. The upper surface of the slurry filled in the molding space is flattened by contact with the lower surface (plane) of the lid member.

  Note that a squeezing step, which will be described later, can be inserted after the charging step and before the closing step. In this case, a portion of the slurry that has risen upward from the upper surface of the mold can be removed by the squeezing process, and the upper surface of the slurry filled in the molding space is flattened by the squeezing process.

  The next curing step is performed with the opening of the mold closed as described above. In this step, “slurry curing” (slurry curing by gelation reaction) proceeds. On the other hand, volatilization of the dispersion medium component of the slurry hardly occurs because the opening of the mold is blocked. Therefore, in this step, “drying of the slurry” (drying of the slurry by volatilization and removal of the dispersion medium component) can hardly proceed, and the hardening of the slurry proceeds mainly.

  By curing the slurry in this curing step, a thin plate-shaped molded body (pre-drying molded body) having an upper surface (plane) as a portion exposed from the opening of the mold is obtained. This curing process cures to such an extent that the molded body before drying can be handled (to the extent that the molded body before drying is not easily damaged when the molded body before drying is gripped or taken up using a hand or a jig). Can be continued.

  This curing step may be performed at normal temperature or may be performed at a temperature higher than normal temperature by heating, but is preferably performed at normal temperature. Thereby, it can suppress that hardening of a slurry (thus, shrinkage | contraction by hardening of slurry) progresses too rapidly, and it can suppress that a crack is formed in the molded object before drying in a hardening process.

  When the curing step is completed, the lid member is removed from the mold in the lid removing step. In the next drying step, the opening of the mold is exposed upward and the molded body before drying is accommodated in the molding space, or is further removed from the molded body before drying. Made in the state. Therefore, volatilization of the dispersion medium component of the slurry is likely to occur in the drying process. On the other hand, the curing of the slurry has already progressed sufficiently and hardly newly proceeds. As a result, in this step, drying of the slurry proceeds mainly.

  By this drying step, the molded body before drying is sufficiently dried, whereby a thin plate-shaped ceramic molded body is obtained. This drying step may be performed at normal temperature or may be performed at a temperature higher than normal temperature by heating, but is preferably performed at a temperature higher than normal temperature by heating. Thereby, the time which a drying process requires can be shortened.

  As described above, in the method according to the present invention, the progress of drying of the slurry is forcibly delayed by performing the curing process in a state where the opening of the mold is closed. That is, first, a time sequence is given in which the curing of the slurry mainly proceeds in the curing step and then the drying of the slurry mainly proceeds in the drying step. By providing such a temporal order, as described above, “slurry curing and slurry drying proceed simultaneously at their natural speeds without any special temporal order. In particular, it has been found that the variation in the thickness of the thin plate-like ceramic molded body is smaller than that in the case of “going”. As a result, it was found that the flatness of the ceramic molded body was improved (increased).

  This is presumed to be based on the following reason. That is, in the curing process, the drying of the slurry hardly proceeds. Therefore, the curing of the slurry can proceed to the same extent in a stable manner in the molding space. In the subsequent drying process, the curing of the slurry hardly proceeds. Therefore, the drying of the slurry can proceed to the same extent in a stable manner in the molding space. As a result, the degree of shrinkage due to the hardening of the slurry and the degree of shrinkage due to the drying of the slurry are unlikely to differ depending on the position of the ceramic molded body. As described above, the thickness variation of the thin plate-shaped ceramic molded body is reduced.

  In the method for producing a ceramic molded body according to the present invention, in the drying step, the upper and lower surfaces of the molded body before drying are sandwiched between two porous filters from which the molded mold has been removed. It is preferable that the molded body before drying is configured to be dried in a state covered with each of the porous filters.

  According to this, as described above, the warpage (swell) of the thin plate-shaped ceramic molded body is particularly small as compared with “when the slurry is dried while the slurry is filled in the molding space”. Thus, it was found that the flatness of the ceramic molded body is improved (increased).

  This is presumed to be based on the following reason. In a state where the thin plate-shaped molded body before drying is sandwiched between two filters, the molded body before drying faces the upper surface of the table (more specifically, on the lower surface side of the molded body before drying). Assume that the drying process is performed by placing the filter on the table (with the lower surface of the filter in contact with the upper surface of the table). Even in this case, the dispersion medium component can be sufficiently volatilized from the lower surface in addition to the upper surface of the molded body before drying through a large number of pores in the filter. That is, a difference in the degree of progress of drying hardly occurs between the upper surface side and the lower surface side of the thin plate-shaped ceramic molded body.

  In addition, when the drying process is performed in a high-temperature furnace, the heat in the furnace is transmitted to the pre-drying molded body through the filter. Therefore, even if there is a difference in temperature (temperature distribution) depending on the position in the high-temperature furnace, the temperature distribution is relaxed and transmitted to the green body before drying. That is, a difference in temperature (temperature distribution) hardly occurs depending on the position of the surface of the molded body before drying. Thus, a difference in the degree of progress of drying hardly occurs between the portions of the thin plate-shaped ceramic molded body. From the above, warpage (swell) of the thin plate-like ceramic molded body is reduced.

  Further, in the method for producing a ceramic molded body according to the present invention, in the charging step, the ceramic slurry partially overflows from the opening of the mold and rises upward from the upper surface of the mold. By moving the squeegee along the plane of the upper surface of the mold after the charging process and before the closing process, the mold space is moved upward from the plane of the upper surface of the ceramic slurry. It is preferable to include a squeezing step for removing the raised portion.

  When the slurry is charged so that a part of the slurry swells upward from the upper surface (opening) of the mold, the mold is closed if the opening of the mold is closed without the squeezing step. The slurry is crushed downward on the lower surface of the lid member in a state where the upper surface of the slurry rising upward from the upper surface of the slurry is not flattened (that is, a state where large irregularities may exist on the upper surface of the slurry) . In this case, bubbles are easily mixed (or a gap is formed) between the upper surface of the slurry to be crushed and the lower surface of the lid member. That is, in the state where the opening of the mold is closed with the lid member, in the portion where bubbles are mixed (or a gap is formed) on the upper surface of the slurry filled in the molding space, the bubble existence region ( Alternatively, the recess corresponding to the gap formation region may still remain. In other words, even after being crushed by the lower surface (flat surface) of the lid member, flattening of the upper surface of the filled slurry cannot be achieved sufficiently. This leads to an increase in thickness variation of the thin plate-like ceramic molded body to be manufactured.

  In addition, in this case, the slurry is crushed downward on the lower surface of the lid member in a state in which the amount rising upward from the upper surface of the mold differs depending on the position. Therefore, the amount by which the slurry is crushed downward on the lower surface of the lid member varies depending on the position. As a result, the density of the slurry filled in the molding space varies depending on the position in a state where the opening of the mold is closed with the lid member. The fact that the density of the slurry varies depending on the position means that the amount of shrinkage caused by the hardening and drying of the slurry also varies depending on the position. This also leads to an increase in the thickness variation of the thin plate-like ceramic molded body to be manufactured.

  On the other hand, when the squeezing step is inserted after the charging step and before the closing step as in the above configuration, the thickness variation of the thin plate-like ceramic molded body is smaller than when the squeezing step is not inserted. It turned out to be smaller. This is because the opening of the mold is blocked by the lid member in the state where the upper surface of the slurry filled in the molding space is flattened. ), And the density variation of the slurry is presumed to be less likely to occur.

  In the method for manufacturing a ceramic molded body according to the present invention, in the closing step, the lid member has an outer shape that can be fitted into the opening of the molding die, and the lid member is in the opening. In a state where the lid member is placed on the mold so as to be fitted and the opening is closed by the lid member, the flat surface of the lower surface of the lid member is caused by the force based on the weight of the lid member. It is preferable that the portion of the ceramic slurry filled in the space that is exposed upward from the opening is constantly pressed downward.

  According to this, as the slurry shrinks due to the hardening of the slurry (thus, the thickness of the molded body before drying decreases), the lid member fits into the opening, and the lower surface (plane) of the lid member While the contact with the upper surface of the molded body before drying is ensured, the lid member descends by a decrease in the thickness of the molded body before drying. Therefore, even after the curing step is completed, contact between the upper surface of the pre-drying molded body and the lower surface (plane) of the lid member can be reliably ensured. As a result, the flatness of the upper surface of the pre-drying molded body (and hence the ceramic molded body) can be more reliably achieved, and the thickness variation of the ceramic molded body becomes smaller.

It is a perspective view of the thin plate-shaped ceramic molded object manufactured by the manufacturing method of the ceramic molded object using the gel cast method which concerns on embodiment of this invention. It is a perspective view of the shaping | molding die used for manufacture of a ceramic molded body. It is a top view of the shaping | molding die used for manufacture of a ceramic molded body. FIG. 4 is a longitudinal sectional view of a molding die cut along the line 4-4 in FIG. 3. FIG. 5 is a view corresponding to FIG. 4 showing a state in which ceramic slurry is charged into a mold. It is a figure corresponding to FIG. 2 which showed the mode at the time of squeezing with a squeegee. FIG. 5 is a diagram corresponding to FIG. 4 illustrating a state when squeegeeing is performed with a squeegee. It is a figure for demonstrating the appropriate conditions at the time of squeezing with a squeegee. It is a figure for demonstrating the appropriate conditions at the time of squeezing with a squeegee. FIG. 5 is a diagram corresponding to FIG. 4 illustrating a state after squeezing is completed. It is a figure corresponding to FIG. 2 which showed the mode at the time of lid | covering with the glass plate on opening of the upper surface of a shaping | molding die. FIG. 5 is a view corresponding to FIG. 4 showing a state when a glass plate is covered with the opening on the upper surface of the mold. FIG. 5 is a view corresponding to FIG. 4 showing a state in which the opening on the upper surface of the mold is closed with a glass plate. It is a figure corresponding to FIG. 4 which showed the mode at the time of a glass plate being removed from the upper surface of a shaping | molding die. FIG. 5 is a view corresponding to FIG. 4 showing a state when the mold is removed from the molded body before drying. It is the perspective view which showed a mode that the molded object before drying was pinched | interposed with two filters. FIG. 5 is a view corresponding to FIG. 4 illustrating a state in which a molded body before drying is sandwiched between two filters. It is a figure corresponding to Drawing 4 showing signs that two filters are removed from a fabrication object before drying. FIG. 5 is a view corresponding to FIG. 4, showing a state before the slurry rising upward from the upper surface of the mold is crushed downward by the plate member. FIG. 5 is a view corresponding to FIG. 4 showing a state after the slurry rising upward from the upper surface of the mold is crushed downward by the plate member. FIG. 5 is a view corresponding to FIG. 4 illustrating a state when the plate member is removed from the upper surface of the mold. It is the top view and front view which showed the ceramic molded body used for experiment. It is a figure which shows the measurement location of the thickness of the several site | part of a ceramic molded body required in order to obtain | require the thickness variation of a ceramic molded body. It is a figure for demonstrating the definition of flatness. It is a figure which shows the measurement location of the height of several site | parts of a ceramic molded body required in order to obtain | require the flatness of a ceramic molded body. It is a figure corresponding to FIG. 2 which showed the mode at the time of covering a opening with the cover member which can be fitted to opening of the upper surface of a shaping | molding die. FIG. 5 is a view corresponding to FIG. 4 illustrating a state when a lid is fitted with a lid member that can be fitted into the opening on the upper surface of the mold. FIG. 5 is a view corresponding to FIG. 4 showing a state in which the opening on the upper surface of the mold is closed with a lid member that can be fitted into the opening. FIG. 29 is a view corresponding to FIG. 28 illustrating a state in which the lower end portion of the lid member is fitted into the opening and the lid member is gradually lowered as the slurry contracts due to the hardening of the slurry. It is a perspective view of the other thin plate-shaped ceramic molded object manufactured by the manufacturing method of the ceramic molded object using the gel cast method which concerns on embodiment of this invention. It is a figure corresponding to FIG. 24 for demonstrating the definition of the flatness of the molded object shown in FIG. It is a figure corresponding to FIG. 17 which showed a mode that the molded object (molded body before drying) shown in FIG. 30 was pinched | interposed with two filters.

  Hereinafter, a method for producing a ceramic molded body (before firing) according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a ceramic molded body 10 manufactured by a method for manufacturing a ceramic molded body using a gel cast method according to an embodiment of the present invention. The ceramic molded body 10 has a thin disk shape. The fired body obtained by firing the ceramic molded body 10 can be widely used for various applications.

  Hereinafter, the manufacturing method of the ceramic molded body 10 which concerns on embodiment of this invention is demonstrated, referring FIGS. First, the mold 20 used in this manufacturing method will be described with reference to FIGS. 2 is a schematic perspective view of the mold 20 and the squeegee 30, FIG. 3 is a plan view (top view) of the mold 20, and FIG. 4 is molded along line 4-4 in FIG. 2 is a longitudinal sectional view of a mold 20 obtained by cutting the mold 20. FIG. As shown in FIGS. 2 to 4, if this mold 20 is used, one ceramic molded body 10 can be formed. In addition, the shaping | molding die which can form the several same-shaped ceramic molded object 10 simultaneously may be used.

  The molding die 20 is made of any material of metal, ceramics, resin, and gypsum and has a rectangular parallelepiped shape. Formed in the upper part of the molding die 20 is a molding space Q defined by the molding surface 21 (a space for filling with slurry and molding, a thin disk-like space having the same shape as a desired ceramic molded body). .

  That is, a circular opening Pin leading to the molding space Q is formed on the upper surface of the molding die 20 (a plane parallel to the XZ plane). The upper surface of the molding space Q coincides with the opening Pin. The ceramic slurry prepared as described below is charged and filled into the molding space Q of the molding die 20 from the opening Pin.

  The squeegee 30 is made of rubber or metal and has a rectangular or square plate shape (flat plate shape) in plan view. The squeegee 30 is movable in the Z-axis direction at a predetermined speed (may be constant or variable) along the upper surface of the mold 20 by a drive mechanism (not shown) (see arrow). Hereinafter, such movement of the squeegee 30 along the upper surface of the mold 20 is also referred to as “squeezing”.

Next, a specific method for manufacturing the ceramic molded body 10 will be described.
(Coating process)
First, a dispersion of a fluororesin with an organic solvent is applied as a mold release agent to the molding surface 21 of the molding die 20 (that is, the surface with which the ceramic slurry contacts). After application, the organic solvent immediately evaporates, and as a result, the fluororesin is fixed to the molding surface 21. Thereby, the mold release property of the ceramic molded object after that can be improved stably. The release agent is applied using a spray method, a dipping method, or the like.

(Preparation process)
Next, a ceramic slurry containing ceramic powder, dispersion medium, polyol, dispersant, gelling agent, and catalyst is prepared. In this example, 100 parts by weight of alumina as a ceramic powder (alumina powder), 29 parts by weight of a polybasic acid ester as a dispersion medium, 0.8 parts by weight of polyvinyl butyral as a polyol, and a polycarboxylic copolymer as a dispersant A mixture of 3 parts by weight, 4.2 parts by weight of diphenylmethane diisocyanate as a gelling agent, and 0.2 parts by weight of an amine catalyst as a catalyst was used as a ceramic slurry.

  Diphenylmethane diisocyanate and polyvinyl butyral (that is, polyol) later become a urethane resin (polyurethane) by the urethane reaction, and later function as an organic binder. As described above, a strong network can be formed by crosslinking between urethane resin molecules.

Further, when a urethane resin is used as the organic binder in this way, the substances mixed for preparing the ceramic slurry are changed into ceramic powder, isocyanate, polyol, solvent, dispersant, and catalyst. Can be classified. In this case, as the ceramic material used as the ceramic powder, an oxide-based ceramic may be used, or a non-oxide-based ceramic may be used. Further, it may be a dielectric material or a magnetic material. For example, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), barium titanate (BaTiO ₃ ), nickel oxide (NiO), cerium oxide (CeO ₂ ), gadolinium oxide (Gd ₂ O ₃ ), silicon nitride ( Si ₃ N ₄ ), silicon carbide (SiC), aluminum nitride (AlN), glass powder and the like can be used. These materials may be used alone or in combination of two or more. Further, the particle diameter of the ceramic material is not particularly limited as long as the slurry can be adjusted and produced.

  The isocyanate is not particularly limited as long as it is a substance having an isocyanate group as a functional group. For example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or a modified product thereof can be used. In addition, in the molecule | numerator, reactive functional groups other than an isocyanate group may contain, and also many reactive functional groups may contain like polyisocyanate.

  The polyol is not particularly limited as long as it has a functional group capable of reacting with an isocyanate group, for example, a hydroxyl group, an amino group, etc. For example, ethylene glycol (EG), polyethylene glycol (PEG), propylene glycol (PG). Polypropylene glycol (PPG), polytetramethylene glycol (PTMG), polyhexamethylene glycol (PHMG), polyvinyl butyral (PVB) and the like can be used.

  The solvent is not particularly limited as long as it dissolves the dispersant, isocyanate, polyol, and catalyst. For example, it is desirable to use a solvent having two or more ester bonds, such as a polybasic acid ester (for example, dimethyl glutarate) or an acid ester of a polyhydric alcohol (for example, triacetin).

  As the dispersant, for example, it is desirable to use a polycarboxylic acid copolymer, a polycarboxylate, or the like. By adding this dispersant, the slurry before molding can have a low viscosity and a high fluidity.

  Although it will not specifically limit as a catalyst if it is a substance which accelerates | stimulates a urethane reaction, For example, a triethylenediamine, hexanediamine, 6-dimethylamino-1-hexanol etc. may be used.

(Input process)
Next, the ceramic slurry is put into the mold 20. This charging is started immediately after the ceramic slurry is prepared. As described above, the ceramic slurry is introduced from the opening Pin. The introduced ceramic slurry enters the forming space Q while dropping downward due to the action of gravity.

  As shown in FIG. 5, the introduction of the ceramic slurry is completed when a portion of the ceramic slurry overflows from the opening Pin and rises upward from the upper surface of the mold 20. The viscosity of the ceramic slurry used in this example is relatively large. Therefore, in a state where the introduction of the ceramic slurry is completed, a region in which the ceramic slurry does not enter (does not spread) in the lower part in the forming space Q may occur.

(Squeezing process)
Next, as shown in FIGS. 6 and 7, the above-described squeegeeing is performed using a squeegee 30. By this squeezing, a portion of the ceramic slurry that is raised upward from the upper surface (opening Pin) of the mold 20 is removed, and the upper surface of the slurry filled in the molding space Q is flattened. In squeezing, a downward force (“squeezing”) is applied to a portion of the ceramic slurry that is in the vicinity of the opening Pin (below the opening Pin) (the portion that has not been removed by the squeegee 30). The downward force by “)” is added.

  This “downward force due to squeezing” can act as a force for spreading the ceramic slurry to every corner in the forming space Q. As a result, even if a region where the ceramic slurry does not enter (does not spread) in the lower portion in the forming space Q as described above, this region disappears due to the action of “downward force due to squeezing”. obtain. That is, the ceramic slurry can be reliably filled in the forming space Q.

  Here, an additional condition for squeezing is added. As shown in FIGS. 8 and 9, when the gap in the vertical direction between the tip (lower end) of the squeegee 30 and the upper surface of the mold 20 is h, the gap h is adjusted to a value in the range of 50 μm to 500 μm. When squeezing is performed in the formed state (the gap h is constant), the ceramic slurry can be more stably and reliably filled in the molding space Q, and the surface corresponding to the opening Pin in the ceramic molded body (that is, the ceramic molded body) It has been found that a flat surface of the upper surface can be obtained. This is considered to be due to the fact that the sufficiently large “downward force due to squeezing” acts stably when the gap h is within this range.

  Further, as shown in FIG. 8, the squeegee 30 is 20 ° to the front side (Z-axis negative direction side) in the moving direction from the state where the plane of the squeegee 30 is perpendicular to the moving direction (Z-axis direction) of the squeegee 30. When squeezing is performed in a state inclined by a certain angle θ of 70 ° (the angle θ is constant), the ceramic slurry can be reliably filled into the forming space Q.

  As shown in FIG. 9, from the state in which the plane of the squeegee 30 is perpendicular to the moving direction (Z-axis direction) of the squeegee 30, the squeegee 30 moves 20 ° to 70 on the rear side (Z-axis positive direction side) in the moving direction. When squeezing is performed in a state inclined by a certain angle θ (° constant θ), the flatness of the surface corresponding to the opening Pin in the ceramic molded body (that is, the upper surface of the ceramic molded body) is improved. can do. These are also considered to be caused by a sufficiently large “downward force due to squeezing” acting stably when the angle θ is within these ranges.

  FIG. 10 shows a state where squeezing has been completed. In this state, the portion of the ceramic slurry that swells upward from the upper surface of the mold 20 is removed, and the ceramic slurry is reliably filled into the molding space Q by the action of “downward force due to squeezing”. Has been. And the upper surface (surface exposed from opening Pin) of the slurry with which the shaping | molding space Q is filled is planarized.

(Closing process)
Next, as shown in FIGS. 11 to 13, a flat glass plate 40 is placed on the upper surface (plane) of the mold 20. As a result, the opening Pin of the mold 20 is closed by the glass plate 40. That is, in this step, the molding space Q is sealed. In this example, the shape of the glass plate 40 viewed from the Y-axis direction matches the shape of the molding die 20 viewed from the Y-axis direction, but as long as the shape can block the entire area of the opening Pin. Any shape may be used.

(Curing process)
Next, the ceramic slurry filled in the forming space Q is cured. As described above, this process proceeds in a state where the opening Pin of the mold 20 is closed by the glass plate 40 (a state where the molding space Q is sealed).

  Usually, after the ceramic slurry is filled in the molding space Q, the slurry is cured by urethane reaction (gelation reaction) (hereinafter, simply referred to as “slurry curing”) and the slurry is removed by volatilization and removal of the dispersion medium component. Drying (hereinafter simply referred to as “slurry drying”) can proceed simultaneously. However, in this step, volatilization of the dispersion medium component of the ceramic slurry hardly occurs due to the molding space Q being sealed. Therefore, in this step, “slurry drying” hardly proceeds, and “slurry curing” mainly proceeds. The “curing of the slurry” proceeds by forming a strong network by crosslinking between urethane resin molecules as described above by the urethane reaction.

  By progress of this “curing of slurry”, a molded body before drying (hereinafter referred to as “pre-dried molded body F”) is obtained (see FIG. 13). This step is such that the pre-drying shaped product F can be handled (to the extent that the pre-drying shaped product F is not easily damaged when the pre-drying shaped product F is gripped or picked up using a hand or a jig). Continue until cured.

  This step may be performed by leaving the mold 20 in a room temperature atmosphere for a predetermined time, or may be performed by maintaining the mold 20 at a predetermined temperature higher than the room temperature atmosphere by heating for a predetermined time. These may be performed in combination. For example, this step is performed by leaving the mold 20 in a room temperature atmosphere for 24 hours. By carrying out this step in a room temperature atmosphere, it is possible to suppress the “curing of the slurry” (and thus the shrinkage due to the “curing of the slurry”) from proceeding too rapidly. It is possible to suppress the formation of cracks.

(Lid removal process)
Next, as shown in FIG. 14, the glass plate 40 is removed from the mold 20. Thereby, the opening Pin of the shaping | molding die 20 is exposed again. As a result, the forming space Q is released from the sealed state, and volatilization of the dispersion medium component from the ceramic slurry (molded body F before drying) is likely to occur (that is, “slurry drying” easily proceeds).

(Release process)
Next, the mold 20 is removed from the molded body F before drying. As shown in FIG. 15, in this step, the molding die 20 to which the molded body F before drying adheres and remains is turned upside down. Thereby, the molded object F before drying leaves | separates from the shaping | molding die 20 by the effect | action of gravity. When the molded body F before drying is difficult to be separated from the mold 20, it is preferable to give the mold 20 a slight vibration. Thereby, the shaping | molding die 20 is removed from the molded object F before drying, and the molded object F before drying can be taken out.

(Drying process)
Next, the ceramic slurry (molded body F before drying) is dried. In this step, as shown in FIGS. 16 and 17, the entire area of the upper and lower surfaces of the molded body F before drying is sandwiched between two porous filters 50 from which the molded mold 20 has been removed. It is performed in a state covered with each porous filter 50. As the porous filter 50, for example, a filter made of ceramic having a porosity of 48 ± 8% and an average pore diameter of 25 ± 10 μm can be used. In this example, the shape of the porous filter 50 viewed from the Y-axis direction matches the shape of the mold 20 viewed from the Y-axis direction, but covers the entire upper and lower surfaces of the pre-drying molded body F. Any shape is possible as long as it is a shape that can be used.

  In this step, the molded body F before drying sandwiched between the two porous filters 50 is such that the lower surface thereof faces the upper surface of the table (that is, the lower surface of the filter 50 on the lower surface side of the molded body F before drying is the table). Can be carried out in a state of being placed on a table (in contact with the upper surface of the substrate). In this state, a force based on the weight of the filter 50 on the upper side of the molded body F before drying acts on the contact surface between the upper surface of the molded body F before drying and the lower surface of the filter 50 on the upper side of the molded body F before drying. The force based on the weight of the pre-drying molded body F and the weight of the upper filter 50 on the contact surface between the lower surface of the molded body F and the upper surface of the lower filter 50 before drying. Works.

  In this step, volatilization of the dispersion medium component of the ceramic slurry is likely to occur due to the fact that the periphery of the green body F before drying is not sealed. On the other hand, the hardening of the ceramic slurry has already progressed sufficiently and hardly newly proceeds. As a result, in this step, “curing of the slurry” can hardly proceed, and “drying of the slurry” mainly proceeds.

  When the “drying of the slurry” is sufficiently advanced, the ceramic molded body 10 can be obtained in a state of being sandwiched between the two porous filters 50. As shown in FIG. 18, the two porous filters 50 are removed from the ceramic molded body 10, and the ceramic molded body 10 can be taken out.

  This step may be performed by leaving the molded body F before drying sandwiched between two porous filters 50 in a room temperature atmosphere for a predetermined time, or by heating the molded body F before drying from the room temperature atmosphere by heating. It may be performed by maintaining a high predetermined temperature for a predetermined time, or may be performed in combination. For example, this process is performed by accommodating the molded body F before drying sandwiched between two porous filters 50 in a high-temperature furnace adjusted to 90 ° C. for 50 hours. By performing this step at a temperature higher than that of the room temperature atmosphere, the time required for this step can be shortened as compared with the case where the step is performed in a room temperature atmosphere.

(Action / Effect)
Hereinafter, the operation and effect of the method for manufacturing a ceramic molded body according to the above-described embodiment of the present invention will be described. In the method for producing a ceramic molded body according to the present embodiment, “the curing step is performed in a state where the opening Pin is closed by the glass plate 40” (item A), “the drying step is two porous filters 50 ”(item B) and“ a squeezing step is inserted between the charging step and the closing step ”(item C), respectively. As a result, a ceramic molded body with good flatness can be obtained. Hereinafter, the experiment conducted in order to confirm each effect | action and effect of item AC is demonstrated.

  As shown in Table 1, in this experiment, a manufacturing method according to a comparative example and manufacturing methods according to Examples 1 to 3 were introduced. Hereinafter, comparative examples and Examples 1 to 3 will be described in order.

<Comparative example>
In the manufacturing method according to the comparative example, the ceramic molded body is obtained in a state where none of the items A to C is executed. Specifically, after the charging process, a crushing process is performed instead of the squeezing process. In the crushing step, as shown in FIGS. 19 and 20, a flat plate shape is formed on the mold 20 into which the ceramic slurry is poured so that a part of the slurry rises upward from the upper surface (plane) of the mold 20. The plate member B is placed. At this time, a downward external force may be applied to the plate member B from above. As the plate member B, the glass plate 40 described above may be used.

  The portion of the slurry that has risen upward from the upper surface of the mold 20 is the lower surface (plane) of the plate member B due to the weight of the plate member B, or in addition to the downward external force applied to the plate member B from above. Is crushed downward. This crushing is continued until the position in the height direction (vertical direction) of the lower surface (plane) of the plate member B substantially coincides with the position in the height direction of the opening surface of the molding die 20 (upper surface of the molding die). The Then, the plate member B is removed from the mold 20 as shown in FIG.

  By this crushing step, the portion of the ceramic slurry that has been raised upward from the upper surface of the mold 20 is filled into the molding space Q, or between the upper surface of the mold 20 and the lower surface of the plate member B. It is removed outside through the gap. Then, the upper surface of the ceramic slurry filled in the forming space Q is flattened by contact with the lower surface (plane) of the plate member B.

  After the crushing step, as shown in FIG. 21, the curing step and the drying step proceed simultaneously while the opening Pin of the mold 20 is exposed and the ceramic slurry is filled in the molding space Q. Hereinafter, this process is referred to as a “curing / drying process”. In the curing / drying step, volatilization of the dispersion medium component of the ceramic slurry is likely to occur due to the opening Pin being exposed upward. Therefore, “curing of the slurry” and “drying of the slurry” proceed simultaneously at their natural (desired) traveling speeds without any special time sequence. As a result, the ceramic slurry is cured and dried to obtain a ceramic molded body.

  As described above, in the manufacturing method according to the comparative example, the crushing process is performed after the charging process, and after the crushing process, the opening Pin of the mold 20 is exposed and the ceramic slurry is filled in the molding space Q. -A drying process is performed.

<Example 1>
In the manufacturing method according to Example 1, a ceramic molded body is obtained in a state where only item A among items A to C is executed. In Example 1, with respect to the comparative example in which the curing / drying process is performed, “the curing process is performed in a state where the opening Pin is blocked by the glass plate 40, and then the drying process is performed in a state where the opening Pin is exposed. Is different ".

  That is, in the manufacturing method according to Example 1, a crushing process is performed after the charging process, and then a curing process is performed through a closing process. And after a lid | cover removal process is performed, a drying process is performed without passing through a mold release process. That is, the drying process is performed in a state where the opening Pin of the mold 20 is exposed and the molded body F before drying is accommodated in the molding space Q.

<Example 2>
In the manufacturing method according to Example 2, a ceramic molded body is obtained in a state where items A and B among items A to C are executed. In Example 2, the drying process is performed in a state where the opening Pin of the mold 20 is exposed and the molded body before drying is accommodated in the molding space Q. This is different in that it is performed in a state where the pre-drying molded product F is sandwiched between the filters 50.

  That is, in the manufacturing method according to Example 2, a crushing process is performed after the charging process, and then a curing process is performed through a closing process. And after a lid | cover removal process is performed, after a mold release process, a drying process is performed in the state by which the molded object F before drying was pinched | interposed with the porous filter 50 of 2 sheets.

<Example 3>
In the manufacturing method according to Example 3, a ceramic molded body is obtained in a state in which all items A to C are executed. That is, the manufacturing method according to Example 3 is exactly the same as the above-described method for manufacturing a ceramic molded body according to the embodiment of the present invention. The third embodiment is different from the second embodiment in which a crushing process is performed between the charging process and the closing process in that a “squeezing process is performed between the charging process and the closing process”.

  In this experiment, three test pieces of ceramic compacts having a thin disk shape shown in FIG. 22 were produced for each production method using the production methods according to the comparative example and Examples 1 to 3. . As the size of the test product, for example, a diameter D = 350 mm and a thickness T = 3 mm were employed (see FIG. 22).

  In this experiment, in Example 1, the curing process was continued for 12 hours in a room temperature atmosphere, and the drying process was continued at 90 ° C. for 20 hours. In Examples 2 and 3, the curing process was continued for 12 hours at room temperature and the drying process was continued for 50 hours at 90 ° C. In the comparative example, the curing / drying process was continued for 12 hours at room temperature and then continued for 20 hours at 90 ° C. In Examples 2 and 3, a ceramic filter having a thickness of 15 mm and a porosity of 48 ± 8% and an average pore diameter of 25 ± 10 μm was used as the porous filter 50.

  Thickness variation and flatness were calculated for each test product produced in this experiment. As the thickness variation, the difference between the maximum value and the minimum value of the respective thickness measurement values at a plurality of thickness measurement points (17 in the example shown in FIG. 23) of the test product was adopted. . Further, the flatness is defined as a variation in height from the reference surface to the upper surface of the test product when the test product is placed on the upper surface (reference surface, plane) of the table as shown in FIG. As the height variation, the difference between the maximum value and the minimum value among the respective height measurement values at a plurality of height measurement points (17 in the example shown in FIG. 25) was adopted. .

  The flatness of the test product is a value reflecting both the influence of the thickness variation of the test product and the effect of the warp (swell) of the test product. In Table 1, the average value of thickness variation and the average value of flatness are shown for each of the comparative example and Examples 1 to 3. Hereinafter, this result will be analyzed.

<Comparison between Comparative Example and Example 1>
First, the comparative example and Example 1 are compared. As can be understood from Table 1, in Example 1, the thickness variation is small and the flatness is small as compared with the comparative example. This is considered based on the following reasons.

  As described above, in the comparative example, in the curing / drying process, each of “slurry curing” and “slurry drying” does not have a special temporal order, and each natural (result) A) Progressing at the same time. Accordingly, the progress degree of “slurry curing” and the progress degree of “slurry drying” are likely to change depending on the position in the molding space. In addition, generally, the degree of shrinkage due to “slurry drying” is greater than the degree of shrinkage due to “slurry hardening”. From the above, in the curing / drying process, the degree of shrinkage of the test product is likely to vary depending on the position (part) of the test product. As a result, the amount of shrinkage in the thickness direction of the test product tends to vary depending on the position of the test product. Therefore, the thickness variation of the test product tends to increase, and as a result, the flatness of the test product tends to increase.

  On the other hand, in Example 1, the progress of “drying of the slurry” is forcibly delayed by performing the curing process in a state where the opening Pin of the mold 20 is closed. Therefore, a time sequence is given in which “curing of the slurry” mainly proceeds in the curing step and thereafter “slurry drying” mainly proceeds in the drying step. That is, in the curing process, “slurry drying” hardly proceeds. Therefore, “curing of the slurry” can proceed to the same extent in a stable manner in the molding space Q. On the other hand, in the subsequent drying step, “curing of the slurry” hardly proceeds. Therefore, the “slurry drying” can proceed to the same extent in a stable manner in the molding space Q. As a result, the degree of shrinkage caused by “curing of the slurry” and the degree of shrinkage caused by “drying of the slurry” are unlikely to differ depending on the position of the test product. As described above, the variation in the thickness of the test product is reduced, and as a result, the flatness of the test product is also reduced.

<Comparison between Example 1 and Example 2>
Next, Example 1 and Example 2 are compared. As can be understood from Table 1, in Example 2, the thickness variation is similar to that in Example 1, but the flatness is small. This is considered based on the following reasons.

  As described above, in Example 1, the drying process is performed in a state where the opening Pin of the mold 20 is exposed and the molded body before drying is accommodated in the molding space Q. Therefore, the progress rate of volatilization of the dispersion medium component from the upper surface of the test product is larger than the progress rate of volatilization of the dispersion medium component from the lower surface. In other words, a difference in the degree of progress of drying tends to occur between the upper surface side and the lower surface side of the test product. As a result, the warp (swell) of the test product tends to increase, and as a result, the flatness of the test product tends to increase.

  On the other hand, in Example 2, the test product sandwiched between the two filters 50 is placed on the table so that the lower surface thereof faces the upper surface of the table, and the drying process is performed. Therefore, the dispersion medium component can be sufficiently volatilized from the lower surface in addition to the upper surface of the test product through the numerous pores in the filter 50. That is, a difference in the degree of progress of drying hardly occurs between the upper surface side and the lower surface side of the test product.

  In addition, in this drying process, the heat in the high-temperature furnace is transferred to the test product through the filter 50. Therefore, even if there is a difference in temperature (temperature distribution) depending on the position in the high temperature furnace, the temperature distribution is relaxed and transmitted to the test product. That is, the temperature difference (temperature distribution) hardly occurs depending on the position of the surface of the test product. This makes it difficult for differences in the degree of progress of drying to occur between the parts of the test product. From the above, the warp (swell) of the test product is reduced. Therefore, the thickness variation is similar to that of the first embodiment, but the flatness is reduced.

<Comparison between Example 2 and Example 3>
Next, Example 2 and Example 3 are compared. As can be understood from Table 1, in Example 3, the thickness variation is small and the flatness is small as compared with Example 2. This is considered based on the following reasons.

  As described above, in Example 2, the crushing process is performed between the charging process and the closing process. Therefore, in a state where the upper surface of the slurry rising upward from the upper surface of the mold 20 is not flattened (that is, a state where large irregularities may exist on the upper surface of the slurry), the slurry is directed downward on the lower surface of the plate member B. It is crushed. In this case, bubbles are easily mixed (or a gap is formed) between the upper surface of the slurry to be crushed and the lower surface of the plate member B. That is, in the state where the opening Pin of the mold 20 is closed by the plate member B, bubbles are mixed (or gaps are formed) on the upper surface of the slurry filled in the molding space Q. Recesses corresponding to the existing regions (or gap formation regions) may still remain. In other words, even after the crushing process is completed, the flattening of the upper surface of the filled slurry cannot be sufficiently achieved. As a result, the thickness variation of the test product tends to increase.

  In addition, when the crushing process is performed, the slurry is crushed downward on the lower surface of the plate member B in a state in which the amount rising upward from the upper surface of the mold 20 varies depending on the position. Therefore, the amount by which the slurry is crushed downward on the lower surface of the plate member B varies depending on the position. As a result, in the state where the opening Pin of the mold 20 is closed by the plate member B, the density of the slurry filled in the molding space Q varies depending on the position. The fact that the density of the slurry varies depending on the position means that the amount of shrinkage caused by the hardening and drying of the slurry also varies depending on the position. This also tends to increase the thickness variation of the test product.

  On the other hand, in Example 3, a squeezing process is performed between the charging process and the closing process. Accordingly, the opening Pin of the mold 20 is closed with the glass plate 40 in a state where the upper surface of the slurry filled in the molding space Q has already been flattened. Therefore, it is difficult for the above-described bubble mixing (or gap formation) and slurry density variation to occur. As described above, the variation in the thickness of the test product is reduced, and as a result, the flatness of the test product is also reduced.

  As described above, in the method for manufacturing a ceramic molded body according to the present embodiment (= Example 3), “the curing step is performed in a state where the opening Pin is closed by the glass plate 40”, and By “inserting the squeezing step between the charging step and the closing step”, the thickness variation of the ceramic molded body can be reduced. In addition, the warpage (swell) of the ceramic molded body can be reduced by “the drying step being performed in a state where the molded body F before drying is sandwiched between the two porous filters 50”. As a result, it is possible to obtain a thin plate-like ceramic molded body having good (small) flatness without adding machining such as cutting.

  In addition, this invention is not limited to the said embodiment, A various modification can be employ | adopted within the scope of the present invention. For example, in the said embodiment, as shown in FIGS. 11-13, as the glass plate 40 used in order to block the opening Pin of the shaping | molding die 20, the shape when it sees from a Y-axis direction is Y of the shaping | molding die 20. The one that matches the shape when viewed from the axial direction is used.

  Therefore, in the state where the glass plate 40 is placed on the upper surface of the molded body 20, the vertical position of the glass plate 40 is fixed. Therefore, in the curing process performed in a state where the glass plate 40 is placed on the upper surface of the molded body 20, when the thickness of the molded body F before drying decreases due to the shrinkage of the slurry by “curing of the slurry”, the glass There is a possibility that the upper surface (the surface exposed from the opening Pin) of the molded body F before drying that has been in contact with the lower surface of the plate 40 is separated from the lower surface of the glass plate 40. This leads to the fact that the flatness of the upper surface of the pre-drying molded body F (and hence the ceramic molded body) cannot be reliably achieved, and consequently leads to an increase in the thickness variation of the ceramic molded body.

  In order to cope with this problem, as shown in FIGS. 26 to 29, the lid member (glass plate) 40 used to close the opening Pin of the mold 20 has an outer shape that can be fitted into the opening Pin. Can be used. In the example shown in FIGS. 26 to 29, a lid member 40 having a thin disk shape having a diameter slightly smaller than the diameter of the opening Pin of the mold 20 is used.

  In this example, while the lid member 40 is guided by the guide member C placed on the upper surface of the mold 20, the lid member 40 is placed on the mold 20 so as to be vertically movable coaxially with the opening Pin. Yes. That is, the lid member 40 is placed on the mold 20 so as to be fitted into the opening Pin.

  Therefore, as shown in FIG. 28, in a state where the opening Pin is closed by the lid member 40, the lower surface (circular plane) of the lid member 40 is caused by the force based on the weight of the lid member 40, thereby The upper surface (the surface exposed from the opening Pin) is always pressed downward. As a result, in the curing step, when the thickness of the molded body F before drying decreases due to the shrinkage of the slurry due to “curing of the slurry”, the lid member 40 is fitted into the opening Pin and the lower surface of the lid member 40 ( The lid member 40 is lowered by the reduced thickness of the green body F before drying while ensuring contact between the flat surface) and the upper surface of the green body F before drying. Therefore, even after the curing step is completed, contact between the upper surface of the pre-drying molded body F and the lower surface (plane) of the lid member 40 can be reliably ensured. As a result, the flattening of the upper surface of the pre-drying molded body F (and hence the ceramic molded body) can be achieved more reliably, and the thickness variation of the ceramic molded body becomes smaller.

  In the above embodiment, a thin disk-shaped ceramic molded body is manufactured. However, the manufacturing method according to the present invention can be applied to any shape of ceramic molded body as long as it is a thin plate. .

  Moreover, in the said embodiment, although the molded object comprised from a single plane on both upper and lower surfaces is manufactured as a thin plate-shaped ceramic molded object, as shown in FIG. 30, only an upper surface is a single plane. A molded body having a concave portion (seven grooves in FIG. 30) formed at one or two or more positions on a single plane may be manufactured. In this case, as the molding die 20, a mold having a projection corresponding to the recess formed on the bottom surface of the molding surface 21 is used.

  In this case, as the “thickness variation”, the difference between the maximum value and the minimum value among the respective thickness measurement values at a plurality of thickness measurement points in the region where the recess (groove) in the test product is not formed. Is adopted. As in the above embodiment, as shown in FIG. 31, the flatness is determined from the reference surface when the test product is placed on the upper surface (reference surface, flat surface) of the table to the upper surface (single plane) of the test product. ) Is defined as the variation in height. As the height variation, the difference between the maximum value and the minimum value among the respective height measurement values at a plurality of height measurement points of the test product is employed.

  Further, in this case, when the drying step is performed in a “state in which the molded body F before drying is sandwiched between the two porous filters”, as shown in FIG. As the filter 50 ′, one having a convex portion corresponding to the concave portion (groove) formed on the upper surface thereof is used. Thereby, the whole area of the lower surface of the green body F before drying can be covered with the upper surface of the porous filter 50 '.

  DESCRIPTION OF SYMBOLS 10 ... Ceramic molded object, 20 ... Mold, 21 ... Molding surface, 30 ... Squeegee, 40 ... Glass plate, 50 ... Porous filter, Pin ... Opening, Q ... Molding space

Claims (6)

Ceramic slurry containing ceramic powder, dispersion medium, and gelling agent is molded using a molding die with an opening leading to the molding space on the upper surface, and at least the upper surface is composed of a single flat surface. A method of manufacturing a ceramic molded body to obtain a thin plate-shaped ceramic molded body,
A charging step of charging the ceramic slurry into the molding space of the mold through the opening of the mold;
A closing step of closing the opening of the molding die with the lid member by placing a lid member having a flat surface on the lower surface on the molding die;
A curing step of obtaining a thin plate-shaped pre-drying molded body by curing the ceramic slurry filled in the molding space by a gelation reaction in a state where the opening of the molding die is closed by the lid member; ,
A lid removing step of removing the lid member from the mold;
In the state where the opening of the mold is exposed and the molded body before drying is accommodated in the molding space, or in the state where the molding mold is further removed from the molded body before drying, the molded body before drying Drying process to obtain the ceramic molded body,
A method for producing a ceramic molded body, comprising: In the manufacturing method of the ceramic molded body of Claim 1,
In the drying step,
The pre-drying molding in a state where the upper and lower surfaces of the pre-drying molded body are covered with the respective porous filters by sandwiching the pre-drying molded body from which the mold has been removed with two porous filters. A method for producing a ceramic molded body configured to be dried. A method for producing a ceramic molded body according to claim 1 or 2,
In the charging step,
The ceramic slurry is poured into the molding space such that a part of the ceramic slurry overflows from the opening of the mold and rises upward from the upper surface of the mold.
After the charging step and before the closing step, the squeegee is moved along the plane of the upper surface of the mold to remove a portion of the ceramic slurry that is raised upward from the plane of the upper surface. A method for producing a ceramic molded body, comprising a squeezing step. In the manufacturing method of the ceramic molded body as described in any one of Claims 1 thru | or 3,
In the closing step,
The lid member has an outer shape that can be fitted into the opening of the mold, and is placed on the mold so that the lid member can be fitted into the opening. A portion where the flat surface of the lower surface of the lid member is exposed upward from the opening in the ceramic slurry filled in the molding space by the force based on the weight of the lid member when the lid member is closed. A method of manufacturing a ceramic molded body configured to always press down. In the manufacturing method of the ceramic molded body as described in any one of Claims 1 thru | or 4,
The said hardening process is a manufacturing method of the ceramic molded body performed at normal temperature. In the method for manufacturing a ceramic molded body according to any one of claims 1 to 5,
The said drying process is a manufacturing method of the ceramic molded body performed at temperature higher than normal temperature by heating.

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