JP4287108B2 - Method and apparatus for producing ceramic green sheet - Google Patents

Description

【００２７】
［３］実施例の効果
溶剤濃度を第１ゾーンで最も高くし、第３ゾーンで溶剤濃度が０体積％となるようにした場合（実施例１及び実施例２）、クラックの発生が抑制される。これにより、気流温度及び成形体温度を成形体が進む方向に徐々に高くし、気体に含まれる溶剤濃度を成形体が進む方向に徐々に小さくした場合、乾燥性能が優れていることが判る。
また、第１ゾーン及び第２ゾーンの気流におけるレイノルズ数を３３００及び１３０００とした場合（実施例１）、クラックの発生は確認されなかった。これにより、成形体が筐体の内部に入ってから上記気流中に含まれる上記溶剤の濃度が１体積％となるまでの間における上記気流のレイノルズ数を２００００以下である３３００とした場合、乾燥性能が極めて優れていることが判る。
更に、実施例１では、この加熱手段２３に循環させる温水の温度は気流の温度よりも高くなるように調整されている。また、この加熱手段２３の温度を第１ゾーンの前方のヒータ２３１よりも中央のヒータ２３２の方が高くなるように調製し更に、成形体５が移動する方向に向かって徐々に上昇するように調整されている。これにより、セラミックグリーンシートに膜が形成されない。従って、乾燥性能がより優れていることが判る。
【００２８】
尚、本発明においては、上記の具体的な実施例に記載されたものに限らず、目的及び用途に応じて、本発明の範囲内で種々変更した実施例とすることができる。例えば、本実施例では、図２に示されるように、筐体２１としてゾーンに分けられたものを用いたが、図３に示されるように、ゾーンに分けられていないものを用いても良い。このとき、筐体２１に形状等は、前記説明製造装置の説明をそのまま適用できる。
また、本実施例では筐体内部のゾーンの数を３としたがこのゾーンの数は特に限定されず、２〜５個のゾーンにわけることができる。
更に、本実施例では、セラミック原料としてジルコニア粉末を使用したが、本発明ではこれに限定されず、例えば、アルミナ粉末等を使用しても同様の効果を得ることができる。
【図面の簡単な説明】
【図１】実施例のセラミックグリーンシートの製造装置の模式図である。
【図２】実施例の乾燥手段の内部構造を示す模式図である。
【図３】本発明における他の態様の乾燥手段の内部構造を示す模式図である。
【符号の説明】
１；成形手段、２；乾燥手段、２１；筐体、２１１；第１ゾーン、２１２；第２ゾーン、２１３；第３ゾーン、２１４；天井部、２２；気流発生手段、２２１；吸気手段、２２２；排気手段、２３；加熱手段、３；移動手段、４；泥漿、５；成形体、６；アニール手段。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a ceramic green sheet and a manufacturing apparatus. More specifically, it is possible to dry in a short time a molded body in which a slurry containing ceramic powder, resin and solvent is formed, and when this molded body is dried, the ceramic green sheet is cracked. The present invention also relates to a method and an apparatus for manufacturing a ceramic green sheet in which unevenness is unlikely to occur on the surface. The ceramic green sheet produced by the present invention is widely used for ceramic laminates such as ceramic sensors and ceramic heaters.
[0002]
[Prior art]
In the production of conventional ceramic green sheets, a slurry containing ceramic powder, resin and solvent is formed into a sheet shape, and the formed body is heated by a heater or the like that circulates hot water from a hot water tank to the inside of the pipe, At the same time, drying is performed by a method of directly applying hot air to the molded body or a method of naturally drying the molded body.
[0003]
[Problems to be solved by the invention]
For ceramic green sheets used for ceramic substrates such as functional ceramic elements or ceramic heaters, high-purity ceramic materials are selected to enhance product performance, and sintering aids are reduced as much as possible. The inferiority, which increases the sintering temperature. However, on the other hand, in a ceramic green sheet used for a ceramic substrate such as a functional ceramic element or a ceramic heater, it is not necessary to raise the sintering temperature because it must be fired simultaneously with the functional ceramic or the conductor. Therefore, a fine powder material having a large specific surface area is usually used as a method for improving sinterability. However, when a fine powder having a large specific surface area is used, it is necessary to increase the amount of resin according to the specific surface area. This is because the amount of resin is small and there is not enough resin on the surface of the ceramic powder, so that the bonding between the powders is weakened and cracks (cracks) are likely to occur in the ceramic green sheet. On the other hand, if the amount of resin is increased in order to prevent the occurrence of cracks, it is difficult to obtain the dimensional accuracy required for the product. This is because the shrinkage ratio during sintering is large and deformation easily occurs. In addition, the ceramic green sheet is difficult to dry. This is because a surface film is easily formed.
Therefore, in order to prevent the generation of cracks and surface coatings, it is necessary to control advanced drying conditions of the green sheet, but there is a problem that it is difficult to control the drying conditions by conventional natural drying or the like.
Furthermore, when the molded body is naturally dried, there is a problem that it takes time until the molded body is completely dried.
[0004]
The present invention has been made in order to solve the above-mentioned problems. The ceramic green has good drying efficiency and facilitates the control of the drying conditions, thereby preventing the formation of cracks and surface coatings on the ceramic green sheet. It aims at providing the manufacturing method and manufacturing apparatus of a sheet | seat.
[0005]
[Means for Solving the Problems]
The method for producing a ceramic green sheet of the present invention includes a molding step of forming a molded body by molding slurry containing ceramic powder, a resin and a solvent into a sheet, and then a drying step of drying the molded body, In the method for producing a ceramic green sheet having the above, the drying step generates an air flow in a direction opposite to the moving direction of the molded body while moving the molded body inside the housing, and the direction in which the molded body moves Gradually increasing the temperature of the molded body toward or keeping the temperature constant, and gradually decreasing the concentration of the solvent contained in the airflow in the direction in which the molded body moves,
The housing is divided into a plurality of zones, and an independent air flow is generated for each zone.
The temperature of the airflow in each zone increases in order with the arrangement order of the plurality of zones toward the direction in which the molded body proceeds. It is characterized by that.
Moreover, the annealing process which anneals the molded object dried by the said drying process can be further provided.
The flow velocity of the airflow is the smallest in the zone where the molded body first enters, and can be gradually increased in the direction in which the molded body moves in each zone.
The Reynolds number of the airflow may be 20000 or less at least during the period from when the molded body enters the housing until the concentration of the solvent contained in the gas constituting the airflow is 1% by volume. it can.
The apparatus for producing a ceramic green sheet of the present invention comprises a molding means for forming a molded body by forming a slurry containing ceramic powder, a resin and a solvent into a sheet, a drying means for drying the molded body, and the molding A moving means for moving the body from the molding means to the drying means, and further moving the inside of the drying means, the drying means includes a casing in which the molded body moves by the moving means; An airflow generating means for flowing an airflow in a direction opposite to the direction in which the molded body moves above the molded body, and a heating means for heating the molded body from at least the lower part; The heating means heats the molded body so as to gradually increase or keep the temperature of the molded body, and the concentration of the solvent contained in the gas constituting the airflow generated by the airflow generating means Body moves The casing is internally divided into a plurality of independent zones, and the airflow generating means includes an intake means for taking gas into each of the zones and each of the airflow generating means. An exhaust means for discharging the gas from the zone is provided, and the air intake means and the exhaust means are arranged above the molded body so that the airflow is generated in a direction opposite to the direction in which the molded body moves. It has been The temperature of the airflow in each zone increases in order with the arrangement order of the plurality of zones toward the direction in which the molded body proceeds. It is characterized by that.
Moreover, an annealing means for annealing the molded body dried by the drying means can be further provided.
Further, the air flow generating means generates the air flow so that the flow velocity of the air flow in the zone where the molded body first enters is the smallest, and the flow velocity gradually increases in the direction in which the molded body moves in each zone. Can be.
Further, the air flow generation means has a Reynolds number of 20000 or less until the concentration of the solvent contained in the gas constituting the air flow reaches 1% by volume after at least the molded body enters the housing. The air flow can be generated.
[0006]
【The invention's effect】
According to the method and apparatus for producing a ceramic green sheet of the present invention, it is possible to effectively prevent a film from being formed on the surface of the molded body by the resin contained in the molded body when the molded body is dried. Thus, the drying efficiency is good, and furthermore, the formation of cracks and irregularities on the ceramic green sheet can be effectively prevented.
In addition, the casing is divided into a plurality of independent zones, and when the airflow is allowed to flow in each independent zone, the temperature, flow velocity, etc. of the airflow can be adjusted at any location inside the drying means. Furthermore, if the flow velocity of the airflow is made the smallest in the zone where the molded body enters first and gradually increases in the direction in which the molded body moves in each zone, a resin film is formed on the molded body. Can be further prevented. Thereby, it can prevent more effectively that a crack and an unevenness | corrugation are formed in a ceramic green sheet.
Furthermore, when the Reynolds number of the airflow is 20000 or less until the concentration of the solvent contained in the airflow is at least 1% by volume, this airflow can be made laminar. Thereby, since it can prevent further that the film | membrane of resin is formed in a molded object, it can prevent more effectively that a crack and an unevenness | corrugation are formed in a ceramic green sheet.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[1] Manufacturing method of ceramic green sheet
The present invention includes a molding step in which a slurry containing ceramic powder, a resin, and a solvent is molded into a sheet to produce a molded body.
The “sludge” is a raw material for the ceramic green sheet and contains ceramic powder, a resin and a solvent.
The “ceramic powder” is a ceramic material of a ceramic green sheet. Examples of the material of the ceramic powder include alumina and zirconia, but are not particularly limited. The specific surface area of the ceramic powder is not particularly limited, but is 2.5 to 6 m. ² / G, preferably 3-5 m ² / G.
The “resin” functions as a binder. Examples of this resin include, but are not limited to, acrylic resins, butyral resins, and urethane resins. Moreover, these may use only 1 type and may use 2 or more types together.
The “solvent” functions as a dispersion medium for the ceramic powder. Examples of this solvent include, but are not limited to, methyl ethyl ketone, toluene, ethanol and the like. Moreover, these may use only 1 type and may use 2 or more types together.
[0008]
The slurry can further contain a plasticizer and a dispersant.
The plasticizer has a function of improving the processability of the green sheet. Examples of the plasticizer include, but are not limited to, dibutyl phthalate, 2-ethylhexyl phthalate, and 2-ethylhexyl adipate. These may use only 1 type and may use 2 or more types together.
The dispersant has a function of improving the dispersibility of the powder during slurry. Examples of the dispersant include, but are not limited to, sorbitan monolaurate, polycarboxylate, nonionic activator, anionic activator, and the like. These may use only 1 type and may use 2 or more types together.
[0009]
A method for producing a molded body from the slurry is not particularly limited, but a method for producing a molded body in a sheet form by applying slurry on a carrier film by a doctor blade method, a slip cast method or the like is preferable.
[0010]
Moreover, this invention has a drying process which dries the said molded object.
The “drying step” means a step of volatilizing the solvent contained in the molded body. At this time, it is performed by flowing the airflow in a direction opposite to the direction in which the molded body moves above the molded body while the molded body moves substantially horizontally inside the housing.
At this time, the above "movement" means that the molded body only needs to be moved in a substantially horizontal direction. If the molded body is substantially horizontal, the path through which the molded body moves may be a straight line or a curved line. . Further, when the passage is straight, it may be bent halfway. For example, as shown in FIG. 1, the molded body 5 is placed on a carrier film 31 and the carrier film 31 is driven by a driving roller 32 as a method of moving the substantially horizontal. .
[0011]
Furthermore, the shape of the “housing” is not particularly limited, but for example, a straight cylindrical shape as shown in FIG. 2 is preferable. Moreover, although the cross-sectional shape of this housing | casing is not specifically limited, It is preferable that it is a rectangle. This is because an airflow described later can be efficiently flowed. Moreover, as this housing | casing, as FIG. 2 shows, the thing divided into the some independent zone is used, and an airflow is flowed for every this independent zone. At this time, the number of the zones is not particularly limited, but is preferably 2 to 10, preferably 2 to 5, and more preferably 3 as shown in FIG.
[0012]
In the present invention, the concentration of the solvent contained in the gas constituting the “air stream” can be gradually decreased in the direction in which the molded body moves. That is, the gas constituting the airflow is in a state where the solvent is contained due to the volatilization of the solvent contained in the molded body, but the concentration of the solvent contained in the gas becomes high when it is shortly after drying. Like that. This is because a large amount of the solvent is volatilized first because the amount of the solvent contained in the molded body is large. Further, since the amount of the solvent contained in the molded body gradually decreases due to the volatilization of the solvent, the concentration of the solvent contained in the gas is lowered as the drying proceeds. And it is preferable that the density | concentration of the solvent contained in gas becomes substantially 0 volume% at the time of completion | finish of drying. The concentration of the solvent is obtained by adding the volume% at the lower explosion limit to LEL% (explosive lower limit reference concentration) measured by a catalytic combustion type combustible gas concentration measuring device adapted to the blended solvent ratio. be able to. Furthermore, the concentration of this solvent is 0.03 to 1.8% by volume in the first zone, preferably 0.05 to 1.5% by volume in the first zone when the housing is divided into three zones. 0 to 0.1% by volume, preferably 0 to 0.05% by volume, and in the third zone 0 to 0.01% by volume, preferably less than 0.01% by volume.
[0013]
In addition, the flow velocity of the airflow is divided into multiple zones In the production method of the present invention, It is preferable that the zone in which the compact enters first is the smallest, and gradually increases in the direction in which the compact moves in each zone. That is, when the molded body moves to the next zone, it is preferable that the flow velocity of the zone in which the molded body enters last is larger than the flow velocity of the previous zone.
This flow rate can be appropriately changed depending on the number of zones provided in the housing, the composition of the slurry, and the like. For example, when there are three zones, the flow velocity of the air flow can be changed as appropriate depending on the composition of the slurry, but in a case of 1.66 m width × 0.25 m height, 0.05 to 0.5 m / sec, preferably 0.1 to 0.3 m / sec, 0.1 to 1.5 m / sec in the second zone, preferably 0.5 to 1.2 m / sec, and 0.3 in the third zone. It can be 1 to 3 m / sec, preferably 1 to 2 m / sec.
[0014]
As a reference invention related to the production method of the present invention When the chassis is not divided into multiple zones Can be considered. In this case The flow rate in the housing is not particularly limited as long as it is sufficiently dried, but it is a casing having a width of 1.66 m × a height of 0.25 m, and more preferably 0.05 to 0.5 m / sec. It can be set to 0.1-0.3 m / sec. At this time, it is preferable that the flow velocity in the housing is small at the beginning and gradually increases as the molded body advances. As a method of changing the flow rate, it is preferable to use a casing in which the longitudinal cross-sectional area of the casing (the cross-sectional area cut in the AA direction in FIG. 3) gradually decreases in the direction in which the molded body 5 advances. At this time, it is preferable that this longitudinal cross-sectional area is the largest on the side where the molded body 5 enters (left side in FIG. 3) and the smallest on the side where the molded body 5 exits.
For example, as shown in FIG. 3, the height of the ceiling portion 214 on the side where the molded body 5 enters is increased, and the casing 21 gradually decreases in the direction in which the molded body 5 travels. Those are preferred. Further, at this time, the height of the ceiling 214 on the side where the molded body 5 enters (left side in FIG. 3) is the highest, and the side where the molded body 5 exits (right side in FIG. 3) is the lowest. Further preferred. Note that the shape of the ceiling portion 214 is not limited to a shape in which the height gently changes as shown in FIG. 3, and for example, it may change in a stepped manner in the direction in which the molded body 5 advances.
[0015]
Further, the Reynolds number of the airflow is not particularly limited as long as the drying is sufficiently performed, but at least 20000 or less from the start of drying until the concentration of the solvent contained in the airflow is 1% by volume or less. , Preferably 10,000 or less, usually 1000 or more. By not making the air current strong turbulent, it is possible to dry without forming a resin film on the molded body, and therefore effectively preventing the occurrence of cracks and uneven thickness of the ceramic green sheet. Because you can. The Reynolds number Re is obtained from the equivalent diameter De of the casing (when the cross section is rectangular: 2 × width × height / (width + height)), the average wind speed u, the fluid density ρ, and the fluid viscosity μ. It is a dimensionless number obtained as Re = De × u × ρ × μ.
[0016]
Moreover, the temperature of this airflow will not be specifically limited if it is a range by which drying is fully performed, but it can be 20-80 degreeC, Preferably it can be 30-70 degreeC. In the case where the housing is divided into three zones, the first zone is 20 to 50 ° C., preferably 30 to 50 ° C., the second zone is 30 to 80 ° C., preferably 40 to 70 ° C. In 3 zones, it can be set to 50-90 degreeC, Preferably it is 50-80 degreeC.
[0017]
In the present invention, the temperature of the molded body is gradually increased or kept constant in the direction in which the molded body moves. The temperature range can be 20 to 90 ° C, preferably 30 to 80 ° C, more preferably 30 to 70 ° C.
Furthermore, in the first zone, 20 to 70 ° C., preferably 30 to 60 ° C., in the second zone 40 to 80 ° C., preferably 40 to 70 ° C., in the third zone 50 to 90 ° C., preferably 60 to 60 ° C. It can be 80 degreeC.
Moreover, as a method of heating this molded object, the method etc. which arrange | position the heater which circulated warm water to the cage | basket below this molded object are mentioned.
At this time, the temperature of the hot water can be gradually increased in the direction in which the molded body moves. That is, the temperature of the hot water is set to be low when it is shortly after drying. And it is preferable to raise gradually the temperature of the warm water of the part corresponding to the direction to which this molded object moves.
In the case where the casing is divided into three zones, it is preferable that this heater is attached below the first zone and below the second zone, and not attached below the third zone.
Further, in the first zone, it is preferable that the temperature is raised shortly after drying, and in the second zone, the height is higher than the first zone or the same temperature.
Furthermore, the temperature of this hot water can be 30 to 50 ° C. in the first zone and 45 to 80 ° C. in the second zone.
Furthermore, it is preferable to adjust the temperature of the hot water so that it is higher than the temperature of the airflow. This is because when the temperature of the hot water is lower than the temperature of the airflow, a film tends to be formed on the ceramic green sheet.
[0018]
In the present invention, the ceramic green sheet (hereinafter also referred to as a dry body) after the drying step can be further annealed. Thereby, the stress concentration generated inside the dry body can be released. Although the method of this annealing is not specifically limited, For example, the method etc. which immerse a dry body in warm water are mentioned.
The thickness of the dried body is not particularly limited, but can be 100 μm or more, preferably 200 μm or more.
[0019]
[2] Manufacturing equipment
The apparatus for producing a ceramic green sheet of the present invention comprises a molding means for forming a molded body by forming a slurry containing ceramic powder, a resin and a solvent into a sheet, a drying means for drying the molded body, and the molding And a moving means for moving the body from the forming means to the drying means in a substantially horizontal direction inside the drying means.
The “molding means” is not particularly limited as long as the molded body can be produced, and examples thereof include a doctor blade method and a slip cast method on a carrier film.
The “moving means” includes, for example, a carrier film 31 for disposing the molded body 5 on the surface thereof as shown in FIG. 1, a roller 32 for driving the carrier film, and a roller 32 for driving the roller 32. And a driving device (not shown) that drives the roller 32 to move the molded body 5 together with the carrier film 31 substantially horizontally.
[0020]
The “drying means” includes a casing, an airflow generating means for generating an airflow in a direction opposite to the direction in which the molded body moves above the molded body, and a heating means for heating the molded body from below. is there.
The “casing” is not particularly limited as long as it is the predetermined one, and it is preferable to use one divided into a plurality of independent zones as shown in FIG. Further, the description of the manufacturing method can be applied as it is to the temperature of the air current in each zone and the concentration of the solvent contained in the gas constituting the air current.
Moreover, in the case of a thing which does not have a plurality of independent zones, it is preferable to use a casing in which the longitudinal sectional area of the casing 21 gradually decreases in the direction in which the molded body 5 advances. At this time, it is preferable that this longitudinal cross-sectional area is the largest on the side where the molded body 5 enters and further the smallest on the side where the molded body 5 exits.
For example, as shown in FIG. 3, the height of the ceiling portion 214 on the side where the molded body 5 enters is high, and the casing 21 gradually decreases in the direction in which the molded body 5 travels. Is preferred. Furthermore, at this time, the height of the ceiling 214 on the side where the molded body 5 enters (left side in FIG. 3) is the highest, and the height of the ceiling 214 on the side where the molded body 5 exits (right side in FIG. 3) is the highest. More preferably, it is lowered. Note that the shape of the ceiling portion 214 is not limited to a shape in which the height gently changes as shown in FIG. 3, and for example, it may change in a stepped manner in the direction in which the molded body 5 advances. At this time, the explanation of the manufacturing method can be applied as it is to the flow velocity, the air temperature, and the concentration of the solvent contained in the gas constituting the air flow.
[0021]
The “air flow generation means” is attached to the housing in order to generate an air flow inside the housing. For example, as shown in FIGS. 2 and 3, the intake cylinder 2211 is moved by the intake fan 2212. In the direction in which the molded body moves above the molded body 5, the intake means 221 that takes gas into the housing 21 through the exhaust fan 2222 and the exhaust means 222 that exhausts air from the housing through the exhaust cylinder 2221. It is preferable that the gas is arranged so that gas flows in the opposite direction.
Further, the concentration of the gas constituting the air flow generated by the air flow generating means is adjusted so as to gradually decrease in the direction in which the molded body moves. Furthermore, the description of the manufacturing method can be applied as it is for the concentration of the gas.
Further, in the case where the air flow generating means is divided into a plurality of independent zones, it is preferable that the air intake means 221 and the exhaust means 222 are formed in each zone as shown in FIG. .
[0022]
Furthermore, the above-mentioned “heating means” is for adjusting the temperature of the molded body by heating the molded body from below, and includes, for example, a heater that circulates hot water through the pipe. Further, the heating means is adjusted so that the temperature of the molded body gradually increases or becomes constant. This is for effectively preventing a film from being formed on the surface of the ceramic green sheet. At this time, the description of the manufacturing method can be applied as it is for the temperature of the molded body. Furthermore, when the casing is divided into independent zones, it is preferable not to arrange this heating means at the location corresponding to the zone through which the molded body passes finally.
[0023]
【Example】
Hereinafter, examples embodying the present invention will be described.
[1] Configuration of manufacturing equipment
The structure of the ceramic green sheet manufacturing apparatus (hereinafter also simply referred to as the present manufacturing apparatus) of this embodiment will be described with reference to FIGS.
As shown in FIG. 1, the manufacturing apparatus includes a molding unit 1 for producing a sheet-like molded body 5 from the slurry 4, a drying unit 2 for drying the molded body 5 to obtain a dried body, and a drying unit 2. It has a moving means 3 for moving the molded body 5 inside the housing 21 and an annealing means 6 for releasing the stress existing in the dry body.
The forming means 1 includes a tank 11 for storing the slurry 4, and a doctor blade 12 for producing a sheet-shaped formed body 5 on the carrier film 31 from the slurry 4.
The moving means 3 includes a carrier film 31 on which the formed molded body 5 is disposed, and a roller 32 that drives the carrier film 31, and the direction indicated by the arrow X together with the carrier film 31 by rotating the roller 32. The molded body 5 moves to the position.
As shown in FIG. 2, the drying unit 2 includes a casing 21, an airflow generating unit 22 that generates an airflow in a direction opposite to the direction in which the molded body 5 moves, and a heating unit that heats the molded body 5 from below. 23.
The casing 21 has a cylindrical shape, and its cross section is a rectangle having a width of 1.66 m and a height of 0.25 m. Further, as shown in FIG. 2, the inside is divided into three zones (first zone 211, second zone 212, and third zone 213). At this time, the length of the first zone 211 is 14 m, the length of the second zone 212 is 10 m, and the length of the third zone 213 is 6 m.
The airflow generation means 22 includes an intake means 221 that takes in gas for generating an airflow in each of the zones 211, 212, and 213 through the intake cylinder 2211 by the intake fan 2212, and an exhaust fan 2222 through the exhaust cylinder 2221. Exhaust means 222 for exhausting air from the zones is disposed in each of the zones 211, 212, and 213, and molding is performed in each of the zones 211, 212, and 213 by the intake means 221 and the exhaust means 222 disposed in each of the zones 211, 212, and 213. Airflow is generated in a direction opposite to the direction X in which the molded body moves above the body 5.
As the heating means 23, heaters 231, 232, 233, 234, and 235 for heating by circulating hot water through a pipe are arranged. Three heaters 231, 232, and 233 are disposed in the first zone 211, and two heaters 234 and 235 are disposed in a portion corresponding to the second zone 212. Further, the heating means 23 is adjusted so that the temperature of the molded body 5 gradually increases or becomes constant.
[0024]
As shown in FIG. 1, the annealing means 6 includes a hot water bath 61 in which the molded body is immersed and a roller 62 for guiding the molded body 5 peeled off from the carrier film 31 to the hot water bath 61.
[0025]
[2] Examples
A ceramic green sheet was manufactured by the above-described manufacturing apparatus under the conditions shown in Table 1, and if the crack was not observed by visually observing whether or not a crack occurred in this ceramic green sheet, The confirmed ones were evaluated as Δ, and the ones with remarkable cracks were evaluated as ×. In addition, the slurry used in Examples 1 and 2 was zirconia powder (specific surface area 3.8 m). ² / G) 100 parts by mass, methyl ethyl ketone 54% by mass, toluene 36% by mass and ethanol 10% by mass (methyl ethyl ketone + toluene + ethanol = 100% by mass) 66.7 parts by mass, butyral resin 11.5 parts by mass In addition, 4.8 parts by mass of dibutyl phthalate as a plasticizer and 0.5 parts by mass of sorbitan monolaurate as a dispersant are mixed.
[0026]
[Table 1]

[0027]
[3] Effects of the embodiment
When the solvent concentration is highest in the first zone and the solvent concentration is 0% by volume in the third zone (Example 1 and Example 2), the generation of cracks is suppressed. Accordingly, it can be seen that the drying performance is excellent when the airflow temperature and the molded body temperature are gradually increased in the direction in which the molded body proceeds and the solvent concentration contained in the gas is gradually decreased in the direction in which the molded body proceeds.
Moreover, when the Reynolds number in the airflow of the 1st zone and the 2nd zone was 3300 and 13000 (Example 1), generation | occurrence | production of a crack was not confirmed. As a result, when the Reynolds number of the airflow during the period from when the molded body enters the housing until the concentration of the solvent contained in the airflow is 1% by volume is 3300, which is 20000 or less, drying is performed. It can be seen that the performance is extremely excellent.
Furthermore, in Example 1, the temperature of the hot water circulated through the heating means 23 is adjusted to be higher than the temperature of the airflow. Further, the temperature of the heating means 23 is adjusted so that the central heater 232 is higher than the heater 231 in front of the first zone, and further, gradually rises in the direction in which the molded body 5 moves. It has been adjusted. As a result, no film is formed on the ceramic green sheet. Therefore, it turns out that drying performance is more excellent.
[0028]
In addition, in this invention, it can be set as the Example variously changed within the range of this invention according to the objective and the application, without restricting to what was described in said specific Example. For example, in this embodiment, as shown in FIG. 2, the casing 21 is divided into zones. However, as shown in FIG. 3, a casing that is not divided into zones may be used. . At this time, the description of the explanation manufacturing apparatus can be applied to the casing 21 as it is.
In this embodiment, the number of zones inside the housing is three, but the number of zones is not particularly limited, and can be divided into 2 to 5 zones.
Furthermore, in this example, zirconia powder was used as the ceramic raw material. However, the present invention is not limited to this. For example, the same effect can be obtained by using alumina powder or the like.
[Brief description of the drawings]
FIG. 1 is a schematic view of an apparatus for producing a ceramic green sheet of an example.
FIG. 2 is a schematic view showing an internal structure of a drying means of an example.
FIG. 3 is a schematic diagram showing the internal structure of a drying means according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1; Molding means, 2; Drying means, 21; Housing | casing, 211; 1st zone, 212; 2nd zone, 213; 3rd zone, 214; Ceiling part, 22: Airflow generation means, 221; Exhaust means, 23; heating means, 3; moving means, 4; slurry, 5; compact, 6; annealing means.

Claims (8)

In a method for producing a ceramic green sheet, comprising a molding step of forming a molded body by molding a slurry containing ceramic powder, a resin and a solvent into a sheet, and then a drying step of drying the molded body.
The drying step generates an air flow in a direction opposite to the moving direction of the molded body while moving the molded body inside the casing, and gradually increases the temperature of the molded body in the direction in which the molded body moves. Or keep the temperature constant, and gradually reduce the concentration of the solvent contained in the airflow in the direction in which the molded body moves,
The housing is divided into a plurality of zones, and an independent air flow is generated for each zone.
The method for producing a ceramic green sheet , wherein the temperature of the airflow in each zone increases in order along with the arrangement order of the plurality of zones in the direction in which the formed body proceeds .   The manufacturing method of the ceramic green sheet of Claim 1 further equipped with the annealing process which anneals the molded object dried by the said drying process.   3. The method for producing a ceramic green sheet according to claim 1, wherein the flow velocity of the airflow is the smallest in a zone where the molded body first enters and gradually increases in a direction in which the molded body moves in each zone.   The Reynolds number of the airflow is set to 20000 or less at least during the period from when the molded body enters the housing until the concentration of the solvent contained in the gas constituting the airflow reaches 1% by volume. The manufacturing method of the ceramic green sheet in any one of 1-3. Molding means for forming a molded body by forming a slurry containing ceramic powder, resin and solvent into a sheet, drying means for drying the molded body, and moving the molded body from the molding means to the drying means And moving means for moving the inside of the drying means,
The drying means has a casing in which the molded body is moved by the moving means, and an air flow is formed in the casing and in a direction opposite to the direction in which the molded body moves above the molded body. An air flow generating means, and a heating means for heating the molded body from at least the lower part,
The heating means heats the molded body so as to gradually increase or keep the temperature of the molded body, and the concentration of the solvent contained in the gas constituting the airflow generated by the airflow generating means is It has been adjusted to gradually lower in the direction the molded body moves,
The casing is internally divided into a plurality of independent zones, and the airflow generation means includes an intake means for taking gas into each zone and an exhaust means for discharging the gas from each zone. Prepared,
The intake means and the exhaust means are disposed above the molded body so that the airflow is generated in a direction opposite to the direction in which the molded body moves.
The apparatus for producing a ceramic green sheet , wherein the temperature of the airflow in each zone increases in order along with the arrangement order of the plurality of zones in the direction in which the formed body proceeds .   6. The apparatus for producing a ceramic green sheet according to claim 5, further comprising annealing means for annealing the compact dried by the drying means.   The airflow generation means generates the airflow so that the flow velocity of the airflow in the zone where the molded body first enters is the smallest, and the flow velocity gradually increases in the direction in which the molded body moves in each zone. The ceramic green sheet manufacturing apparatus according to claim 5 or 6.   The air flow generating means has a Reynolds number of 20000 or less during a period from when the molded body enters the inside of the housing until the concentration of the solvent contained in the gas constituting the air flow reaches 1% by volume. The apparatus for producing a ceramic green sheet according to any one of claims 5 to 7, wherein an air flow is generated.

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