JP6447422B2 - Cylindrical forming mold, cylindrical ceramic molded body and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cylindrical forming die for forming a cylindrical ceramic molded body used as a sputtering target in a magnetron rotary cathode sputtering apparatus, and a cold isostatic pressing method using this cylindrical forming die. The present invention relates to a method for manufacturing a cylindrical ceramic molded body and a cylindrical ceramic molded body obtained by the manufacturing method.

  The magnetron type rotary cathode sputtering apparatus is attracting attention because it can realize a higher film formation rate and improved use efficiency of the sputtering target as compared with the flat plate type magnetron sputtering apparatus. A cylindrical sputtering target is used in the magnetron rotary cathode sputtering apparatus. As a material for the cylindrical sputtering target, metal materials that can be easily processed into a cylindrical shape and have high mechanical strength are widely used, but ceramic materials are still widespread due to their low mechanical strength and brittleness. It has not reached.

  Ceramic cylindrical sputtering targets can be manufactured by spraying ceramic powder on the outer periphery of a cylindrical backing tube or by spraying ceramic powder on the outer periphery of a cylindrical backing tube. It is limited to a hot isostatic pressing (HIP) method or the like in which ceramic powder is fired in an active atmosphere. However, the thermal spraying method has a problem that it is difficult to obtain a high-density target. In addition, the HIP method has high initial cost and running cost, may cause peeling due to a difference in thermal expansion, and has a problem that the target and backing tube cannot be recycled.

  On the other hand, a cylindrical shape by a cold isostatic pressing (CIP) method using a cylindrical forming die disclosed in JP-A-6-71628, JP-A-10-85994, JP-A-2012-139842 and the like. A method for manufacturing a ceramic molded body has been proposed. In particular, the cylinder forming mold disclosed in JP-A-10-85994 and JP-A-2012-139842 is provided separately from the pressure vessel from the viewpoint of improving the handling property, and the ceramic powder is formed outside the pressure vessel. Can be filled.

  There are various types of cylindrical forming molds, and an example having a basic structure is shown in FIG. The cylinder forming die 1 of this example supports a columnar core rod 2, a cylindrical mold frame 3 arranged concentrically outside the core rod 2, and the core rod 2 and the mold frame 3 from the axial direction. The lid 4 is composed of an upper lid 5 and a lower lid 6. The core rod 2 is usually made of a hard material having a rigid and smooth surface such as a metal, an alloy, or a hard plastic. On the other hand, the mold 3 and the lid 4 are made of an elastic material such as urethane rubber, silicone rubber, natural rubber, or candy rubber having a durometer hardness (JIS K 6253: 2006) of about 30 ° to 60 °. The lid 4 may be made of a hard material.

  In the example shown in FIG. 3, the lid 4 is fitted and fixed to the core rod 2. Alternatively, the lid body 4 can be fixed to the core rod 2 by means such as screwing, and the lower lid 6 of the lid body 4 may be integrated with the core rod 2. Is possible. In any case, in the conventional structure, for the purpose of preventing the ceramic powder 7 to be filled from leaking out from the internal space formed by the core rod 2, the mold 3, and the lid 4, the lid 4 is the core. The rod 2 is fixed in a state where axial displacement is prevented.

  When a cylindrical ceramic molded body is obtained by the CIP method using a cylindrical forming mold having such a structure, particularly when a hard material is used as the lid 4, the spring back of the mold 3 made of an elastic material is used. Due to the influence, there is a problem that a defect such as a crack occurs in the obtained cylindrical formed body.

  For such a problem, for example, in Japanese Patent Application Laid-Open No. 2015-16632, each of an upper lid and a lower lid constituting a lid is formed into a hollow disk shape, and is movable in the axial direction with respect to the core rod. It is disclosed that, by using an elastic material having a durometer hardness of 40 ° to 70 ° for the 4 and the mold 3, the chipping caused by springback at the time of pressure release is suppressed in the CIP method.

By the way, there is a demand for reducing the amount of PVA as a binder in order to increase the density of the sintered body and reduce the firing time in the binder removal temperature range during firing. However, in a molded body with a small amount of PVA, the strength is remarkably reduced to 5 N / mm ² or less, and thus cracking may occur after molding. In particular, when spherical ceramic powder having poor crushability is used, since the deformation of the powder is small in the CIP method, the bonding force between the powders is weak, and the mold disclosed in JP-A-2015-16632 is used. In some cases, cracks may occur after molding. In addition, a minute crack that cannot be visually confirmed at the time of molding may be generated, and due to such a crack, the molded body may be cracked at the time of firing. For this reason, at present, the actual situation is that a cylindrical ceramic molded body for a cylindrical sputtering target having a breaking strength of 5 N / mm ² or less has not been commercialized.

Japanese Patent Laid-Open No. 6-071628 Japanese Patent Laid-Open No. 10-085994 JP 2012-139842 A Japanese Patent Laying-Open No. 2015-016632

The present invention provides a cylindrically formed shape that can easily obtain a cylindrical ceramic molded body without cracking by the CIP method even when the amount of the binder is reduced or a spherical ceramic powder having poor crushability is used. By realizing the mold, an object is to provide a cylindrical ceramic molded body for a cylindrical sputtering target having a strength of 5 N / mm ² or less at a practical level.

  The cylindrical forming mold of the present invention includes a cylindrical core rod made of a hard material, a cylindrical mold frame concentrically arranged on the outer side of the core rod, and an upper lid and a lower lid made of an elastic material. And a lid that supports the core rod and the mold from the axial direction.

  In particular, in the cylinder-forming mold of the present invention, each of the upper lid and the lower lid is provided on the inner surface facing each other in the assembled state of the cylinder-forming mold on the core rod and both axial ends of the mold. Each has an engaging groove that can be engaged, and the outer surface on the opposite side of the raw powder filling portion of the upper lid and the lower lid has a counterbore diameter of 50% to 80% with respect to the radial width of the powder feeding portion. A counterbore part is provided, and the thickness of the part provided with the counterbore part is 3 mm to 10 mm.

  The mold and the lid are made of at least one selected from urethane rubber, silicone rubber, candy rubber, and natural rubber having a durometer hardness (JIS K 6253: 2006) in the range of 30 ° to 70 °. The core rod is preferably made of a metal, an alloy, or a hard plastic.

  Moreover, it is preferable to provide the elastic support member attached to the outer peripheral surface of the said formwork, and supporting this formwork from the outside.

  The method for producing a cylindrical ceramic formed body of the present invention is characterized in that the cylindrical forming mold is used when a cylindrical ceramic formed body is obtained by a cold isostatic pressing (CIP) method. More specifically, the cylindrical forming mold of the present invention is combined, and an internal space formed inside the cylindrical forming mold is filled with raw material powder comprising at least a ceramic powder and a binder, and is subjected to cold isostatic pressing. By molding the raw material powder, a cylindrical ceramic molded body is obtained. In particular, in the present invention, the amount of the binder is kept in the range of 0.5% by mass or more and less than 2.0% by mass with respect to the amount of the ceramic powder.

  More specifically, in a state where the cylindrical forming molds are combined, a filling step of filling the raw material powder into a space formed by the core rod, the mold, and the lid, and after the filling step The cylinder-forming mold filled with the raw material powder is formed at a holding pressure of 98 MPa to 294 MPa, a pressure forming step by cold isostatic pressing, and after the forming step, the pressure is reduced from the holding pressure to 20 MPa, A cylindrical ceramic molded body is obtained by a pressure-lowering step of reducing the pressure from 20 MPa to normal pressure over 10 to 40 minutes.

As the raw material powder, it is preferable to use a raw material powder having a tap density (JIS Z 2504: 2012) of 1.1 g / cm ³ or more.

  When the raw material powder is filled in the cylinder forming mold, it is preferable to apply vibration to the cylinder forming mold.

The cylindrical ceramic molded body of the present invention comprises a ceramic molded body containing a ceramic component and a binder, and has a breaking strength of 1 N / mm ² or more and 5 N / mm ² or less, and the amount of the binder is It is the range of 0.5 mass% or more and less than 2.0 mass%.

  ADVANTAGE OF THE INVENTION According to this invention, the cylinder formation type | mold which can manufacture a high quality cylindrical ceramic molded object without a crack and remarkable deformation | transformation is provided. In addition, according to the present invention, even when a cylindrical ceramic powder having a poor crushability is used, by using this cylindrical forming mold and performing pressure molding by the CIP method, a high amount of binder can be obtained. It becomes possible to obtain a quality cylindrical ceramic molded body at a level that is industrially practical. Therefore, the industrial significance of the present invention is very great.

FIG. 1 is a schematic sectional view showing an example of an embodiment of a cylinder forming mold according to the present invention. FIG. 2 is a schematic sectional view showing another example of the embodiment of the cylinder forming mold of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of a conventional cylinder forming mold.

  In view of the above-mentioned problems, the present inventors have disclosed a spring back and a mold frame in a cylinder-forming mold composed of a core rod made of a hard material, a mold frame made of an elastic material, and a lid. The structure which eliminates the time lag of mold release at the time of pressure reduction of a lid was studied earnestly. As a result, the present inventors have provided a counterbore part on the upper and lower lids of the cylindrical mold, thereby reducing the thickness of the lid and reducing the difference in thickness from the mold, thereby reducing the mold at the time of decompression. The present invention has been completed by obtaining the knowledge that cracks and cracks can be reduced by eliminating the time lag between the mold and the lid.

  Hereinafter, the present invention is divided into a cylindrical forming mold, a support member for an outer peripheral surface applied to a preferred embodiment, a method for manufacturing a cylindrical ceramic molded body, and a cylindrical ceramic molded body to be obtained. Explained. The size of the cylindrical ceramic molded body of the present invention is not particularly limited. In the following, the cylindrical ceramic molded body having an outer diameter of 195 mm to 200 mm, an inner diameter of 155 mm to 160 mm, and a total length of 200 mm to 250 mm. The case of obtaining is described as an example.

In the present invention, as described later, the cylindrical powder may be filled as a raw material powder with ceramic powder mixed with the binder as it is, but the ceramic powder is filled with pure water, binder, and dispersion. After mixing with a material or the like, spray drying may be performed to obtain a granulated powder, and the granulated powder may be filled into a cylindrical mold as a raw material powder.
(1) Cylinder-forming mold FIG. 1 shows an example of a cylinder-forming mold 1a according to an embodiment of the present invention. The cylindrical forming mold 1a basically includes a cylindrical core rod 2, a cylindrical mold 3 arranged concentrically outside the core rod 2, an upper lid 5a, and a lower lid 6a as in the conventional structure. It comprises a core 4 and a lid 4a that supports the mold 3 from the axial direction.

  The core rod 2 is comprised from the hard material which does not deform | transform at the time of the press by a cold isostatic press (CIP) method. Examples of such hard materials include metals such as iron and copper, alloys based on these metals, and hard resins having excellent mechanical strength and wear resistance such as MC nylon. Depending on the conditions of pressing by the CIP method, a material that is relatively hard with respect to the mold 3 and the lid 4a, specifically, candy rubber, natural rubber, or the like may be used as the material constituting the core rod 2. Sometimes.

  As the core rod 2, a cylindrical one is usually used, but it is tapered from one end side to the other end side from the viewpoint of facilitating extraction of the core rod 2 from the obtained cylindrical ceramic molded body after forming by the CIP method. You may use what provided (draft angle). In this case, the gradient θ is preferably 0 ° to 0.30 °, and more preferably 0 ° to 0.15 °.

  The core rod 2 is required to have an outer diameter that is approximately the same as the inner diameter of the target cylindrical ceramic molded body. When the inner diameter of the ceramic molded body is slightly larger than the outer diameter of the core rod 2 due to the spring back when the pressure during CIP molding is released, the above-mentioned molded body having an inner diameter of 155 mm to 160 mm is obtained. The core rod 2 having an outer diameter of 154 mm to 159 mm is used.

  For the mold 3 and the lid 4a, an elastic material made of at least one selected from urethane rubber, silicone rubber, candy rubber, and natural rubber is used. Preferably, an elastic material having a durometer hardness (JIS K 6253: 2006) obtained using a durometer hardness tester in the range of 30 ° to 70 °, more preferably a durometer hardness of 40 ° to 50 °. A range of elastic materials is used. When different elastic materials are used for the mold 3 and the lid 4a, the hardness difference (durometer hardness difference) between the mold 3 and the lid 4a is 10 ° or less, preferably 5 ° or less, more preferably 3 ° or less. It is preferable that

  By restricting the hardness of the mold 3 and the lid 4a to such a range, it is possible to reduce the influence of the springback in the pressure-lowering process while suppressing the deformation of the cylindrical mold 1 in the filling process. Become. When the durometer hardness is less than 30 °, the mold 3 and the lid 4a are deformed by the weight of the raw material powder 7 in the filling step, and a cylindrical ceramic molded body having a desired shape cannot be obtained. On the other hand, when the durometer hardness exceeds 60 °, or the hardness difference exceeds 10 °, it acts on the cylindrical ceramic molded body when the mold 3 and the lid 4a are restored to the original shape in the pressure reduction process. There is a risk that large shearing stress will be generated and large cracks will be visible. Alternatively, fine cracks (micro cracks) are generated, and the cylindrical ceramic sintered body may be cracked starting from the micro cracks in the subsequent firing step or processing step.

  As the mold 3, there is no problem even if some deformation occurs during pressing by the CIP method. Therefore, it is preferable to use candy rubber in consideration of the cost during mass production. On the other hand, as the lid body 4a, it is necessary to suppress deformation of the lid body 4a during pressing, and it is preferable to use silicone rubber in consideration of durability.

The sizes of the upper lid 5a and the lower lid 6a constituting the mold 3 and the lid body 4a are also selected in consideration of molding conditions by the CIP method according to the size and density of the target cylindrical ceramic molded body. The That is, when a cylindrical ceramic molded body is obtained by the CIP method, a pressure of about 98 MPa to 294 MPa (1000 kgf / cm ^{2 to} 3000 kgf / cm ² ) is usually applied. Based on the dimensions of the ceramic molded body, the dimensions of each part of the cylindrical mold 1 are determined based on experiments and simulations based on the material of the cylindrical mold 1 and the properties such as the bulk density and tap density of the raw material powder 7 to be used. It is determined as appropriate.

  When the mold 3 and the lid 4a have the above-described hardness, the thickness of the mold 3 is preferably 5 mm to 20 mm, and more preferably 6 mm to 10 mm. The thicknesses of the upper lid 5a and the lower lid 6a constituting the lid 4a are preferably 10 mm to 50 mm, more preferably 10 mm to 40 mm, and still more preferably 20 mm to 30 mm. Thereby, it becomes possible to further reduce the influence of the springback in the step-down process while suppressing the deformation of the cylindrical forming mold 1 in the filling process. If the thickness of each of the upper lid 5a and the lower lid 6a is less than 10 mm, the lid body 4a cannot withstand the weight of the filled raw material powder, the lid body 4a is deformed, and handling becomes difficult. On the other hand, if these thicknesses exceed 50 mm, the mold 3 cannot withstand the weight of the lid 4a (upper lid 5a), and the mold 3 may be deformed.

  The mold 3 is configured in a cylindrical shape having an inner diameter sufficiently larger than the outer diameter of the core rod 2 as in the conventional cylindrical mold. For example, when trying to obtain the above-described cylindrical ceramic molded body having an outer diameter of 195 mm to 200 mm, the mold 3 having an inner diameter of 220 mm to 238 mm is used.

  The lid body 4a of this example includes an upper lid 5a and a lower lid 6a that support the core rod 2 and the mold 3 from the axial direction. Each of the upper lid 5a and the lower lid 6a has a first engaging groove 8 that can be engaged with both axial ends of the core rod 2 on the inner surface facing each other in the assembled state of the cylindrical mold 1 and the die. A second engagement groove 9 is provided that can be engaged with both axial ends of the frame 3.

  The outer diameter of the lid body 4a (the upper lid 5a and the lower lid 6a) is preferably 5 mm or more, more preferably 5 mm to 16 mm larger than the outer diameter of the mold 3. That is, in a state where the lid 4a and the mold 3 are combined, the outer periphery of the lid 4a is preferably 2.5 mm or more, more preferably about 2.5 mm to 8 mm in the radial direction from the outer periphery of the mold 3. Protruding. When the protrusion amount of the outer peripheral portion of the lid body 4a is less than 2.5 mm, the lid body 4a is provided on the frame body 3 when the lid body 4a is provided with the second engaging groove 9 that is a fitting portion with the mold frame 3. Cannot be stably fixed, and it becomes difficult to prevent deformation of the mold 3 during pressing by the CIP method. The upper limit of the amount of protrusion of the lid 4a should be set as appropriate depending on the conditions of pressing by the CIP method, but when the amount of protrusion of the lid 4a exceeds 8 mm, the pressure acting on this protrusion The lid 4a may be deformed.

  Thus, the lid 4a is provided with the first engaging groove 8 and the second engaging groove 9 which are the fitting portions between the core rod 2 and the mold 3, so that the cylinder forming mold 1 can be used in the filling process. Even when the cylindrical forming die 1a is deformed due to the weight of the raw material powder 7 filled therein, it is possible not only to effectively suppress the leakage of the raw material powder 7, but also to prevent cracks during pressing. It is possible to suppress chipping due to springback during generation or pressure release.

  Further, in this example, the upper lid 5a and the lower lid 6a are each provided with an outer surface on the opposite side of the raw material powder filling portion in the assembled state of the cylindrical mold 1a with respect to the radial width W of the powder feeding portion. A counterbore part 10 having a counterbore diameter of% to 80%, preferably a counterbore diameter of 30% to 40%, is provided.

  By providing such counterbore 10 on the outer surfaces of the upper lid 5a and the lower lid 6a, in the cylindrical forming mold of the present invention, when the pressure is reduced from the maximum pressure to the normal pressure during pressing by the CIP method, the upper lid 5a and the lower lid 6a, where the counterbore part 10 is provided is separated from the mold on the lower pressure side, so even when the thickness of the upper lid 5a and the lower lid 6a is increased, the gap between the lid 4a and the mold 3 Thus, it is possible to effectively suppress the occurrence of a time lag of mold release. Further, since the influence of the spring back of the upper lid 5a and the lower lid 6a is reduced, the occurrence of cracks and cracks is more effectively prevented.

  When the counterbore diameter of the counterbore part 10 exceeds 80% with respect to the radial width W of the powder feeding part, handling during work becomes difficult and work efficiency deteriorates. On the other hand, when the ratio is less than 50%, the contact width between the portion of the upper lid 5a and the lower lid 6a where the counterbore 10 is provided and the obtained cylindrical ceramic molded body is narrowed. The effect of cannot be obtained sufficiently. Further, the counterbore part 10 is 4 mm or more in the radial direction from the first engaging groove 8 and the second engaging groove 9 which are fitting parts with the core rod 2 and the mold 3, preferably 5 mm to 5 mm, respectively. It is preferable to separate about 6 mm. If the radial thickness of the upper lid 5a and the lower lid 6a between the counterbore 10 and the first engagement groove 8 and the second engagement groove 9 is less than 4 mm, a problem occurs in the strength of the lid 4a. It is.

  Of the upper lid 5a and the lower lid 6a, the axial thickness of the elastic material at the place where the counterbore portion 10 is provided is preferably in the range of 3 mm to 10 mm, more preferably in the range of 5 mm to 8 mm. When the thickness is less than 3 mm, the elastic material constituting the upper lid 5a and the lower lid 6a is too thin, and therefore, there is a possibility of tearing during compression, and handling becomes difficult. On the other hand, if it exceeds 10 mm, a time lag with the mold 3 occurs with respect to the mold separation of the lid 4a, so that the effect of the present invention cannot be sufficiently obtained. For example, in the case where the lid 4a has a thickness of 30 mm, the depth of the counterbore 10 is about 25 mm, and the axial thickness of the elastic material at the location where the counterbore 10 is provided in the upper lid 5a and the lower lid 6a. Is about 5 mm.

In the present invention, in order to further reduce the influence of the spring back, stearic acid is applied to the core rod 2, the upper lid 5a, and the lower lid 6a, or it interferes with the raw material powder 7 of the upper lid 5a and the lower lid 6a. It is also effective to attach tack paper or Kent paper to the part.
(2) Elastic Support Member FIG. 2 shows another example of the cylinder forming die 1b according to the embodiment of the present invention. The cylindrical forming mold 1b of this example includes at least one (three in FIG. 2) elastic support members 11 that are attached to the outer peripheral surface of the mold 3 and support the mold 3 from the outside. Thereby, not only can the deformation of the cylindrical forming die 1b due to the weight of the raw material powder 7 filled in the cylindrical forming die 1b in the filling step be effectively suppressed, but also the spring back in the pressure reducing step. It becomes possible to reduce the influence of. As a result, it is possible to obtain a high-quality cylindrical ceramic molded body having almost no density unevenness, cracks and deformation.

  The cylinder forming mold 1b preferably further includes a fixing means 12 for fixing the mold 3 and the elastic support member 11. Such a fixing means 12 is not particularly limited, and an adhesive, a hook-and-loop fastener, or the like can be used.

  Further, the shape of the elastic support member 11 is limited as long as the mold 3 is supported from the outside, and deformation of the cylindrical mold 1b in the filling process and spring back in the pressure reducing process can be suppressed. Rather, any shape such as a belt shape or an annular shape can be adopted. However, it is preferable to use a belt-like elastic support member 11 that can appropriately adjust the supporting force for the mold 3.

  When a resin tape having an adhesive applied to one surface of the substrate 13 is used as the elastic support member 11, the elastic support member 11 has a breaking strength at 25 ° C. (JIS L 1096) of 2 kg / cm to 15 kg / It is preferable to use a cm member. If the breaking strength is less than 2 kg / cm, the effects of the present invention may not be sufficiently obtained. On the other hand, if the breaking strength exceeds 15 kg / cm, the elastic support member 11 cannot follow the compression amount of the cylindrical forming mold 1b in the molding process, and the position of the elastic support member 11 is shifted or significant. May fall off from the cylinder forming mold 1b.

  As the base material 13 of the elastic support member 11, for example, a material composed of at least one selected from polyester, polyimide, polyethylene and polypropylene can be used. On the other hand, as the fixing means 12 (adhesive), a natural rubber adhesive, an acrylic resin adhesive, a styrene-butadiene rubber solution adhesive, or the like can be used.

  The elastic support member 11 may be wound around the mold 3 in an annular shape, or may be wound around and fixed in a spiral shape. In any case, the thickness, width, and number of the elastic support members 11 need to be appropriately selected according to the breaking strength.

  For example, when the elastic support 11 having a breaking strength in the above range is wound around the mold 3 in an annular shape and fixed, the thickness of the elastic support 11 is set to 0.025 mm to 0.150 mm, and the width thereof is set to the mold 3. The axial length is preferably 3% to 50%. Moreover, it is preferable to wind the elastic support body 11 1-5 about an axial direction, and it is more preferable to wind 2-4. A single elastic support 11 can be used to spirally wind about 1 to 5 turns.

  As the fixing means 12, a pair of hook-and-loop fasteners attached to the outer peripheral surface of the mold 3 and one surface of the base material 13 of the elastic support member 11 can be used instead of the adhesive. When a hook-and-loop fastener is used as the fixing means 12, not only the elastic support member 11 can be reused, but also the winding position of the elastic support member 11 can be easily finely adjusted.

  In this case, it is preferable to use the elastic support member 11 having a breaking strength (JIS L 1096) at 25 ° C. of 20 kg / cm to 90 kg / cm. The reason why a larger value is required for the breaking strength of the elastic support member 11 than in the case of using a pressure-sensitive adhesive is that the elastic support member 11 is used repeatedly.

For example, when the elastic support 11 having a breaking strength within the above range is wound around the mold 3 in an annular shape and fixed, the thickness of the elastic support 11 is set to 0.5 mm to 4.0 mm, and the width thereof is set to the mold 3. The axial length is preferably 3% to 50%.
(3) Method for Producing Cylindrical Ceramic Molded Body The method for producing the cylindrical ceramic molded body of the present invention is a cylinder-forming mold of the present invention as a cylinder-forming mold when using a cold isostatic press (CIP) method. Basically, it is the same as in the prior art except that is used. For this reason, below, the main point of the manufacturing method mainly including the characteristic part of this invention is demonstrated.

  In the present invention, as described above, the ceramic powder may be mixed with the binder at a predetermined ratio, and then filled as it is into the cylindrical mold as the raw material powder, but the desired composition is obtained in advance. Thus, it is preferable that the ceramic powder is weighed, mixed with pure water, a binder, a dispersant, and the like, dried, and granulated powder, and then the granulated powder is filled as a raw material powder into a cylindrical mold. Since such a granulated powder has high fluidity, filling into a cylindrical mold is good and high packing density is obtained.

The ceramic powder is not particularly limited, and is appropriately selected according to the composition of the target cylindrical ceramic molded body. For example, in order to obtain a molded body made of ITO (Indium Tin Oxide), indium oxide (In ₂ O ₃ ) powder and tin oxide (SnO ₂ ) powder can be used, and AZO (Aluminum Zinc Oxide). in order to obtain a molded body made of, it is possible to use an aluminum oxide (Al 2 _{O 3)} powder and zinc oxide (ZnO) powder.

The raw material powder to be filled in the cylinder forming mold preferably has good fluidity and high bulk density and tap density. In particular, the tap density is more preferably 1.10 g / cm ³ or more, and more preferably not more than 1.40 g / cm ³ or more 1.90 g / cm ^3. If the tap density is less than 1.10 g / cm ³ , a predetermined amount of raw material powder may not be filled. Here, the tap density represents the density after tapping the sample powder collected in the container 100 times based on JIS Z 2504: 2012, and can be measured using a shaking specific gravity measuring instrument.

  In addition, when using granulated powder as raw material powder, the average particle diameter of this granulated powder becomes like this. Preferably it is 150 micrometers or less, More preferably, you may be 0.5 micrometer-80 micrometers. By controlling the average particle size of the granulated powder within the above range, the filling property of the raw material powder can be further improved. The average particle size can be measured by a laser scattering type particle size distribution measuring apparatus.

  In the present invention, the amount of the binder is kept in the range of 0.5% by mass or more and less than 2.0% by mass, preferably in the range of 0.7% by mass to 1.6% by mass with respect to the amount of the ceramic powder. . This is smaller than the binder amount of about 2.0% by mass to 4.0% by mass with respect to the amount of ceramic powder, which has been conventionally required. When the amount of the binder with respect to the amount of the ceramic powder becomes 2.0% by mass or more, when the cylindrical ceramic molded body is fired under predetermined conditions to obtain the cylindrical ceramic sintered body, a considerable amount of time is required for the binder removal. It becomes necessary and the firing time becomes longer, and the necessity of using the cylindrical mold of the present invention is eliminated.

  In addition, when a spherical ceramic powder with poor crushability is used, the ceramic powder is less deformed during compression, the anchor effect between the ceramic powders is not born, and the bonding force between the ceramic powders is weakened. For this reason, when the cylinder forming mold is separated from the cylindrical ceramic molded body at the time of decompression, there is a high possibility that the cylindrical ceramic molded body is cracked due to the weak bonding force of the raw material powder. On the other hand, when the cylindrical forming mold of the present invention is used, the influence of the spring back can be reduced, so that a cylindrical ceramic molded body without cracks can be produced.

  The method of filling the raw material powder into the cylinder forming mold is not particularly limited, but a certain amount of the raw material powder is filled, the cylindrical forming mold is vibrated, and the position of the upper surface of the raw material powder is sufficiently lowered. After confirming the above, it is preferable to repeat the operation of filling the raw material powder again a plurality of times. By filling the raw material powder by such a method, not only the packing density can be increased, but also the raw material powder can be filled more uniformly. The strength of vibration is not particularly limited as long as vibration is transmitted to the raw material powder.

  A general CIP method and molding conditions can be applied to the method for producing a cylindrical ceramic molded body of the present invention.

  Specifically, the holding pressure in the CIP method is preferably 98 MPa or more, more preferably 98 MPa or more and 294 MPa or less. If the pressure is within such a range, a cylindrical ceramic molded body having sufficient mechanical strength can be efficiently molded. On the other hand, if it is less than 98 MPa, the raw material powder, more specifically, the ceramic powder constituting the raw material powder can be hardened, but the mechanical strength cannot be made sufficient. You have to pay attention.

  The time for holding the holding pressure (holding time) is preferably 1 minute to 30 minutes, and more preferably 3 minutes to 10 minutes. If the holding time is less than 1 minute, the density of the obtained cylindrical ceramic molded body cannot be made sufficiently high. On the other hand, if the holding time exceeds 30 minutes, productivity will deteriorate.

After completion of the holding at the holding pressure, the pressure is reduced from the holding pressure to the normal pressure. Preferably, the pressure is reduced from 20 MPa to the normal pressure in the range of 10 minutes to 40 minutes. Since the restoration of the compression-deformed cylinder-shaped mold proceeds mainly in the range from 20 MPa to normal pressure, the obtained cylindrical ceramic molded body is subjected to shear stress from the form-frame and lid of the cylinder-shaped mold. receive. Therefore, in order to prevent cracks from occurring in the obtained cylindrical ceramic molded body in the step-down step, it is important to control the step-down time during this time to an appropriate range. In this example, the pressure reduction time is preferably 10 minutes to 40 minutes, more preferably 20 minutes to 30 minutes.
(4) Cylindrical ceramic molded body The cylindrical ceramic molded body of the present invention includes a ceramic component and a binder and has a breaking strength (JIS R 1601: 2008) of 1 N / mm ² or more and 5 N / mm ² or less, and a binder. The amount is in the range of 0.5% by mass or more and less than 2.0% by mass with respect to the ceramic component. The method for producing a cylindrical ceramic molded body according to the present invention uses a rubber mold having a durometer hardness in the range of 30 ° to 70 °, even if the fracture strength of the molded body is 5 N / mm ² or less. It is possible to industrially use a cylindrical ceramic molded body having no crack.

  A cylindrical ceramic sintered body is obtained by firing the cylindrical ceramic formed body of the present invention under predetermined conditions. Furthermore, after finishing processing such as grinding, and adjusting the dimensions of each part, the cylindrical ceramic sintered body is processed into a predetermined dimension, and then a cylindrical backing tube through a bonding material such as a low melting point solder. Is joined to obtain a cylindrical sputtering target.

  Since the cylindrical ceramic molded body of the present invention has a small amount of PVA as a binder, it is possible to shorten the firing time in the above firing step, and thus the cost for producing the cylindrical sputtering target is reduced. Is done. Specifically, in the cylindrical ceramic molded body of the present invention, the binder amount is in the range of 0.5% by mass or more and less than 2.0% by mass, preferably 0.7% by mass to 1.% by mass with respect to the ceramic component. It is in the range of 6% by mass. In addition, the ratio of the amount of PVA as a binder to the ceramic component in the cylindrical ceramic molded body is basically the same as the ratio of the amount of PVA as a binder to the raw material powder at the time of filling.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention should not be limited by these examples and comparative examples.

Example 1
First, as ceramic powder, indium oxide powder and tin oxide powder are weighed so that the ratio of tin oxide powder is 10% by mass, and the amount of polyvinyl alcohol (PVA) is 1.4% by mass with respect to the ceramic powder. Then, PVA is added, and pure water and a dispersant are added so that the ceramic powder concentration becomes 65% by mass to obtain a slurry, and this slurry is obtained by a bead mill (manufactured by Ashizawa Finetech Co., Ltd., LMZ type). Mixed and crushed. The amount of the binder was less than the usual addition amount (ratio of PVA to ceramic powder: 2.2% by mass).

The average particle size of the indium oxide powder and the tin oxide powder contained in this slurry was measured using a laser diffraction type particle size distribution measuring device (manufactured by Shimadzu Corporation, SALD-2200) and found to be 0.4 μm. . Then, this slurry was dried using a spray dryer (Okawara Kako Co., Ltd., ODL-20 type) to obtain a granulated powder. The average particle size of the granulated powder was measured using a laser diffraction type particle size distribution analyzer, and found to be 30 μm. Moreover, it was 1.51 g / cm < ³ > when the tap density of granulated powder was measured using the shaking specific gravity measuring device (Kuramo Scientific Instruments Seisakusho make, KRS-409).

  A core rod with an outer diameter of 162 mm, a length of 340 mm, an inner diameter of 232 mm, an outer diameter of 244 mm, and a length of 340 mm are prepared, and the inner surface is fitted with the core rod and the mold frame (engagement groove: depth 20 mm). And an upper cover and a lower cover having an outer diameter of 254 mm and a thickness of 30 mm were prepared. With respect to the radial direction of the upper lid and the lower lid, the counterbore part is provided 4 mm outside from the fitting part with the core rod and 4 mm inside from the fitting part with the mold frame, its inner diameter is 170 mm, its outer diameter is 224 mm, its The depth was 25 mm. The width of the counterbore part was 77% with respect to the radial width of the powder supply part.

  In this cylinder forming mold, the mold was made of candy rubber having a durometer hardness (JIS K6253: 2006) of 48 °, and the lid was made of silicone rubber having a durometer hardness of 40 °. Moreover, the core rod was comprised of MC nylon (manufactured by Quadrant Polypenco Japan Ltd., registered trademark) of HRR120 with Rockwell hardness.

  The cylinder-forming mold was combined except for the upper lid of the lid, and placed on the vibrator. In this state, the granulated powder was filled as a raw material powder to a position about half the axial direction of the cylindrical mold. Here, vibration was applied by a vibrator, and it was confirmed that the position of the upper surface of the raw material powder was sufficiently lowered. Thereafter, the raw material powder was filled up to the upper end position of the cylindrical mold, and was vibrated with a vibrator, and similarly, it was confirmed that the position of the upper surface of the raw material powder was sufficiently lowered.

  By repeating this operation several times, a predetermined amount of raw material powder was filled, and then the upper lid of the lid was combined with the core rod and the mold. This is put into a bag for vacuum packaging, vacuum sealed, inserted into a pressure vessel of a cold isostatic press, subjected to a cold isostatic press at a pressure of 294 MPa, and then lowered from the holding pressure to 20 MPa. In addition, a cylindrical ceramic molded body was obtained by reducing the pressure from 20 MPa to normal pressure over about 20 minutes. This cylindrical ceramic molded body had an outer diameter of 198.0 mm, an inner diameter of 161.0 mm, and an overall length of 298 mm. Further, the cylindrical ceramic molded body was free from defects such as cracking and chipping.

A sample was cut out from this cylindrical ceramic molded body, subjected to three-point bending with a tensile / compression tester (SDWS-2012-SL manufactured by Imada Seisakusho), and the force (breaking strength) immediately before the sample was broken was measured. As a result, the breaking strength of the molded body was 4.0 N / mm ² .

  This cylindrical ceramic molded body is placed in an electric furnace (manufactured by Marusho Denki Co., Ltd.), the heating rate is 0.5 ° C./min up to 1550 ° C., the firing temperature is 1550 ° C., the holding time is 20 hours, and the atmosphere Gas: Pure oxygen gas (oxygen 100%), atmospheric gas flow rate (total amount): 20.0 L / min, cooling rate (˜100 ° C.): 0.7 ° C./min. Got the body. In addition, the time of the whole baking process was shortened by 78 hours compared with the case where a temperature increase rate was set to normal 0.2 degreeC / min.

  No cracks or cracks could be confirmed in the obtained cylindrical ceramic sintered body. This cylindrical ceramic sintered body was processed in the outer diameter, inner diameter, and length direction using a cylindrical grinder. Thereafter, cleaning was performed, but no cracks or cracks were found in the cylindrical ceramic sintered body. Finally, the processed workpiece was bonded to a backing tube to obtain a cylindrical sputtering target. At this time, heat close to 200 ° C. was applied to the processed body, but no cracks or cracks were generated in the processed body.

  Regarding the evaluation of cylindrical ceramic compacts, the cylindrical ceramic compacts were visually observed and those with no defects such as cracks or significant deformation were evaluated as “good” (◯), and these defects were confirmed. Was evaluated as “bad (×)”.

(Example 2)
A cylindrical ceramic molded body, a cylindrical ceramic sintered body, and a cylindrical sputtering target were obtained in the same manner as in Example 1 except that the amount of PVA relative to the ceramic powder was 0.6% by mass.

When the same measurement and evaluation as in Example 1 were performed, the average particle size of the indium oxide powder and the tin oxide powder was 0.39 μm, the average particle size of the granulated powder was 28 μm, and the tap density of the granulated powder was 1 The breaking strength of the .55 g / cm ³ cylindrical ceramic molded body was 1.2 N / mm ² . Further, no cracks or cracks could be confirmed at the time of the cylindrical ceramic molded body, and no cracks or cracks were found in the cylindrical ceramic sintered body even after firing. Furthermore, the cylindrical ceramic sintered body was processed and the processed body was bonded to the backing tube, but the cylindrical sputtering target could be completed without causing defects such as cracks to the end.

Example 3
A cylindrical ceramic molded body, a cylindrical ceramic sintered body, and a cylindrical sputtering target were obtained in the same manner as in Example 1 except that the amount of PVA relative to the ceramic powder was 1.9% by mass.

When the same measurement and evaluation as in Example 1 were performed, the average particle diameter of the indium oxide powder and the tin oxide powder was 0.4 μm, the average particle diameter of the granulated powder was 30 μm, and the tap density of the granulated powder was 1 .53g / cm ^3, breaking strength of the cylindrical ceramic body was 4.9 N / mm ^2. Further, no cracks or cracks could be confirmed at the time of the cylindrical ceramic molded body, and no cracks or cracks were found in the cylindrical ceramic sintered body even after firing. Furthermore, the cylindrical ceramic sintered body was processed and the processed body was bonded to the backing tube, but the cylindrical sputtering target could be completed without causing defects such as cracks to the end.

(Example 4)
A counterbore part with an inner diameter of 172 mm, an outer diameter of 221 mm, and a depth of 25 mm is formed 5 mm outside from the fitting part of the core lid of the upper lid and lower lid and 5 mm inside from the fitting part of the mold, and the width of the counterbore part is supplied. A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that the width was 71% with respect to the radial width of the powder part. The breaking strength of the cylindrical ceramic molded body was 4.0 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Example 5)
A counterbore part with an inner diameter of 176 mm, an outer diameter of 218 mm, and a depth of 25 mm is formed 7 mm outside from the fitting part of the core rod of the upper lid and the lower lid, and 7 mm inside from the fitting part of the formwork. A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that the width in the radial direction of the powder part was 60%. The breaking strength of the cylindrical ceramic molded body was 3.8 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Example 6)
A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that the depth of the counterbore part was 27 mm and the thickness of the part where the counterbore part of the upper and lower lids was 3 mm. The breaking strength of the cylindrical ceramic molded body was 3.9 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Example 7)
A cylindrical ceramic molded body was produced in the same manner as in Example 6 except that the amount of PVA with respect to the ceramic powder was 0.6% by mass. The breaking strength of the cylindrical ceramic molded body was 1.3 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Example 8)
A counterbore part having an inner diameter of 178 mm, an outer diameter of 216 mm, and a depth of 20 mm is formed 8 mm outside from the fitting part of the core rod of the upper lid and the lower lid and 8 mm inside from the fitting part of the mold, and the width of the counterbore part is supplied. A cylindrical ceramic molded body was produced in the same manner as in Example 6 except that the thickness was 54% with respect to the radial width of the powder part, and the thickness of the part where the counterbore part of the upper lid and lower lid was formed was 10 mm. The breaking strength of the cylindrical ceramic molded body was 1.4 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

Example 9
The strip breaking strength (JIS L 1096: 2010) at 25 ° C. is 5.6 kg / cm as an elastic support member at equal intervals on the upper, middle and lower portions in the axial direction of the outer peripheral surface of the cylindrical mold. , A width of 25 mm (7.3% of the axial length of the formwork), a thickness of 0.13 mm, and a polyethylene tape coated with an acrylic resin adhesive on one side (manufactured by Teraoka Seisakusho, A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that each of the P-cut tapes was wound and fixed one turn at a time. The breaking strength of the cylindrical ceramic molded body was 4.0 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Example 10)
A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that spherical tin oxide powder was used as the tin oxide powder among the ceramic powders. The breaking strength of the cylindrical ceramic molded body was 1.2 N / mm ² . Thereafter, a cylindrical sputtering target was produced in the same manner as in Example 1, but no cracks or cracks occurred until the bonding was completed.

(Comparative Example 1)
A cylindrical ceramic molded body was produced in the same manner as in Example 1 except that no counterbore was formed on either the upper lid or the lower lid, and cracks occurred in the molded cylindrical ceramic molded body. It was confirmed. When the strength of the sample obtained from the broken pieces was measured, the breaking strength was 4.1 N / mm ² .

(Comparative Example 2)
A cylindrical ceramic molded body was produced in the same manner as in Example 2 except that no counterbore was formed on either the upper lid or the lower lid, and cracking occurred in the molded cylindrical ceramic molded body. It was confirmed. When the strength of the sample obtained from the broken pieces was measured, the breaking strength was 1.3 N / mm ² .

(Comparative Example 3)
Example, except that the depth of the counterbore part was 28 mm, the thickness of the part where the counterbore part of the upper lid and the lower lid was formed was 2 mm, and the amount of PVA with respect to the ceramic powder was 1.3% by mass As in the case of No. 1, a cylindrical ceramic molded body was produced. As a result, the portion of the upper lid where the counterbore portion was formed was extended by the weight of the raw material powder, and the deformation increased. When molding was carried out as is in the same manner as in Example 1, no cracks were confirmed in the molded cylindrical ceramic molded body, but the deformation was so large that it was far from tolerance, and the desired dimensions could not be obtained. confirmed. When the strength of the sample obtained from the cylindrical ceramic molded body was measured, the breaking strength was 1.6 N / mm ² .

(Comparative Example 4)
An attempt was made to produce a cylindrical ceramic molded body in the same manner as in Example 1 except that the depth of the counterbore part was 18 mm and the thickness of the part where the counterbore part of the upper and lower lids was 12 mm. Although the forming mold was not deformed and the workability was improved, the springback and the time lag of the mold separation could not be eliminated, and the obtained cylindrical ceramic molded body was cracked. When a sample was obtained from the broken piece and its strength was measured, its breaking strength was 3.8 N / mm ² .

(Comparative Example 5)
A counterbore part with an inner diameter of 180 mm, an outer diameter of 214 mm, and a depth of 25 mm is formed 9 mm outside from the fitting part of the core rod of the upper lid and lower lid and 9 mm inside from the fitting part of the mold, and the width of the counterbore part is supplied. An attempt was made to produce a cylindrical ceramic molded body in the same manner as in Example 1, except that the width in the radial direction of the powder part was 49%. However, since the width of the counterbore part is large, the supporting force of the core rod and the formwork is weak and handling becomes difficult, and workability is lowered. Although cracks were not confirmed in the obtained cylindrical ceramic molded body, it was confirmed that the deformation was so large that it was far from the tolerance, and the desired dimensions could not be obtained. When the strength of the sample obtained from the molded body was measured, the breaking strength was 3.6 N / mm ² .

(Comparative Example 6)
A counterbore part with an inner diameter of 168 mm, an outer diameter of 226 mm, and a depth of 25 mm is formed 3 mm outside the fitting part of the core rod of the upper lid and lower lid and 3 mm inside of the fitting part of the mold, and the width of the counterbore part is supplied. Except for setting it to 83% with respect to the radial width of the powder part, an attempt was made to produce a cylindrical ceramic molded body in the same manner as in Example 1, but the cylindrical forming mold was not deformed, but the workability was improved. As a result, the time lag of the springback and mold separation could not be resolved, and cracks occurred in the obtained cylindrical ceramic molded body. When the strength of the sample obtained from the molded body was measured, the breaking strength was 3.5 N / mm ² .

(Comparative Example 7)
A counterbore part with an inner diameter of 168 mm, an outer diameter of 226 mm, and a depth of 28 mm is formed 3 mm outside the fitting part of the core rod of the upper lid and lower lid and 3 mm inside of the fitting part of the mold, and the width of the counterbore part is supplied. The cylindrical ceramic molded body was the same as in Example 2 except that it was 83% with respect to the radial width of the powder part, and the thickness of the part where the counterbore part of the upper lid and lower lid was formed was 2 mm. I tried to make it. However, handling was poor and workability was difficult. When molding was carried out in the same manner as in Example 1, it was confirmed that a desired dimension could not be obtained although cracking did not occur in the formed cylindrical ceramic molded body. It was also confirmed that the cylinder forming mold was cracked. When the strength of the sample obtained from the molded body was measured, the breaking strength was 1.2 N / mm ² .

(Comparative Example 8)
A counterbore part having an inner diameter of 180 mm, an outer diameter of 214 mm, and a depth of 18 mm is formed 9 mm outside from the fitting part of the core rod of the upper lid and lower lid and 9 mm inside from the fitting part of the mold, and the width of the counterbore part is supplied. A cylindrical ceramic molded body was formed in the same manner as in Example 1 except that the width was 49% with respect to the radial width of the powder part, and the thickness of the part where the counterbore part of the upper lid and lower lid was formed was 12 mm. Produced. Although workability was improved, cracks occurred because the time lag of springback and mold separation could not be resolved. When the strength of the sample obtained from the cylindrical ceramic molded body was measured, the breaking strength was 4.2 N / mm ² .

(Comparative Example 9)
A cylindrical ceramic molded body, a cylindrical ceramic sintered body, and a cylindrical sputtering target were obtained in the same manner as in Example 1 except that the amount of PVA with respect to the ceramic powder was 2.2 mass% as in the conventional case. .

When the same measurement and evaluation as in Example 1 were performed, the average particle diameter of the indium oxide powder and the tin oxide powder was 0.4 μm, the average particle diameter of the granulated powder was 30 μm, and the tap density of the granulated powder was 1 0.5 g / cm ³ , the breaking strength of the cylindrical ceramic molded body was 5.0 N / mm ² . Thereafter, firing was performed in the same manner as in Example 1. As a result, binder removal was insufficient, and cracks were generated in the fired cylindrical ceramic formed body.

(Comparative Example 10)
A cylindrical ceramic molded body was formed in the same manner as in Example 1 except that no counterbore was formed on either the upper lid or the lower lid, and that a spherical tin oxide powder was used as the tin oxide powder of the ceramic powder. As a result, it was confirmed that cracks occurred in the formed cylindrical ceramic molded body. When the strength of the sample obtained from the broken pieces was measured, the breaking strength was 1.2 N / mm ² .

DESCRIPTION OF SYMBOLS 1, 1a, 1b Cylindrical formation type | mold 2 Core rod 3 Formwork 4, 4a Lid body 5, 5a Upper lid 6, 6a Lower lid 7 Raw material powder (ceramic powder)
8 First engagement groove 9 Second engagement groove 10 Counterbore part 11 Elastic support member 12 Fixing member 13 Base material

Claims (9)

A cylindrical core rod made of a hard material;
A cylindrical mold that is arranged concentrically on the outside of the core bar and made of an elastic material;
A lid that consists of an upper lid and a lower lid made of an elastic material, and supports the core rod and the mold frame from the axial direction;
With
Each of the upper lid and the lower lid is provided with engagement grooves that can be respectively engaged with the core rod and both axial ends of the mold on the inner surfaces facing each other in the assembled state of the cylindrical mold. In addition, a counterbore part having a counterbore diameter of 50% to 80% with respect to the radial width of the powder supply part is provided on the outer surface on the opposite side of the raw powder filling part of the upper lid and the lower lid, and the counterbore part is provided. Configured so that the thickness of the portion is 3 mm to 10 mm,
Cylindrical mold.   The mold and the lid are made of at least one selected from urethane rubber, silicone rubber, candy rubber, and natural rubber having a durometer hardness (JIS K 6253: 2006) in the range of 30 ° to 70 °. The cylindrical mold according to claim 1.   The cylinder forming mold according to claim 1, wherein the core bar is made of a metal, an alloy, or a hard plastic.   The cylindrical forming mold according to any one of claims 1 to 3, further comprising an elastic support member attached to an outer peripheral surface of the mold and supporting the mold from the outside.   A method for producing a cylindrical ceramic molded body using the cylindrical forming mold according to any one of claims 1 to 4 when obtaining a cylindrical ceramic molded body by a cold isostatic pressing method.   A cylindrical ceramic molded body obtained by combining the cylindrical forming mold, filling an internal space formed inside the cylindrical forming mold with raw material powder composed of at least ceramic powder and a binder, and molding the raw material powder. The cylindrical ceramic molded body according to claim 5, wherein the amount of the binder is in a range of 0.5% by mass or more and less than 2.0% by mass with respect to the amount of the ceramic powder. Manufacturing method.   In a state where the cylindrical forming molds are combined, a filling step of filling a raw material powder composed of at least ceramic powder and a binder into a space formed by the core rod, the mold, and the lid, and the filling After the step, the cylindrical forming mold filled with the raw material powder was formed by pressing with a holding pressure of 98 MPa to 294 MPa by cold isostatic pressing, and after the forming step, the pressure was reduced from the holding pressure to 20 MPa. Thereafter, it comprises a step of lowering pressure from 20 MPa to normal pressure over 10 to 40 minutes, and the amount of the binder is 0.5% by mass or more and less than 2.0% by mass with respect to the amount of the ceramic powder. The method for producing a cylindrical ceramic molded body according to claim 5, wherein the range is as follows. The method for producing a cylindrical ceramic formed body according to any one of claims 5 to 7, wherein a raw material powder having a tap density of 1.1 g / cm ³ or more is used as the raw material powder.   The method for producing a cylindrical ceramic formed body according to claim 6 or 7, wherein vibration is applied to the cylindrical forming mold when the cylindrical powder is filled with the raw material powder.

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