JP2019005752A - One-end sealed type cylindrical ceramic substrate for separation membrane, and manufacturing method of the same - Google Patents

Abstract

To provide a one-end sealed type cylindrical ceramic substrate for a separation membrane which suppresses deterioration in separation performance of a separation membrane filter.SOLUTION: With a one-end sealed type cylindrical ceramic substrate 10 for a separation membrane, a dense glass layer 18 is formed on an outside surface of a sealing part 14 which is anchored on one-side opening of a cylindrical part 12 of a porous ceramic substrate 16 to seal the opening and in which a projection 20 having a fracture surface having a surface structure different from that of the cylindrical part 12 is formed. This configuration enables a defect-free uniform separation membrane to be formed on a surface of the one-end sealed type cylindrical ceramic substrate 10 for the separation membrane, thereby suppressing significant deterioration in separation performance of the separation membrane due to generation of local leaks or the like.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a one-end-sealed cylindrical ceramic in which one end of a cylinder is sealed, and more particularly to a technique for suppressing deterioration in separation performance of a separation membrane filter using the same.

  Separation membrane filters are widely used for solid-liquid separation, liquid separation, gas-liquid separation, and gas separation. A separation membrane filter has a function of separating only components to be separated from a fluid to be treated such as a gas or a liquid, but in many cases, the separation membrane filter has a low mechanical strength by itself to improve the permeability of the fluid to be treated. And is carried on the surface of a cylindrical substrate having mechanical strength. In particular, separation membrane filters in which an inorganic porous membrane that functions as a separation membrane such as alumina, silica, zeolite, and carbon is formed on a ceramic porous substrate are used in the fields of petrochemistry, food chemistry, and energy industries. (MF membrane), ultrafiltration membrane (UF membrane), nanofiltration membrane (NF membrane), reverse osmosis membrane (RO membrane), pervaporation membrane (PV membrane), vapor filtration membrane (VP membrane), etc. Yes.

  The separation membrane filter is used in a gas or liquid separation device, for example, joined to one end of a joining member that collects the separated fluid from the inside of the separation tank to the outside. In joining a separation membrane filter carrying a separation membrane to a gas or liquid separation device, in addition to joining one opening edge and one end of the joining member, the other opening is made airtight by, for example, a sealing member. If it is necessary to seal, and the airtightness of the sealing portion is not ensured, there is an increased risk of mixing the fluid to be processed into the processed fluid. Therefore, it is sufficient to take care to hermetically seal one part of the joint with the joining member when mounted on the separation device, and there is a need for a one-end sealed porous cylindrical ceramic that is open only on one side. Conventionally, one-end-sealed porous cylindrical ceramics manufactured by various manufacturing methods have been proposed. On the other hand, Patent Document 1 discloses a one-end sealed cylindrical ceramic obtained by integrally forming a cylindrical portion of a base material and a sealing portion that seals an opening on one side of the cylindrical portion by an extrusion molding method. Proposed.

  For example, in FIG. 1 of Patent Document 1, a base that forms the outer peripheral surface shape of the cylindrical portion, a core that is formed at the predetermined position inside the base, which forms the inner peripheral surface shape of the cylindrical portion, and a sealing portion The piston has a hemispherical portion that forms the inner peripheral surface shape of the inner end of the metal core and is slidably provided inside the metal core, and the hemispherical concave surface that forms the outer peripheral surface shape of the sealing portion is the opening of the base. An extrusion molding machine is used, which is provided so as to be detachable from the die so as to oppose, and has an outer mold having a through hole on the concave surface through which the extruded molding base is discharged from the sealing portion molding space to the outside. One-end-sealed cylindrical ceramics formed by this method have been proposed. After the molding base is pushed out until a part of the molding base filled in the extrusion molding machine is discharged from the sealing portion molding space through the through hole of the outer mold, the outer mold is removed, and the cylindrical portion has a desired length. Therefore, the piston is slid in the direction in which the tip is separated from the inside of the metal core. Continuous mass production of one-end sealed cylindrical ceramics with a cylindrical part and a sealing part integrally formed with a mechanical strength and high airtightness by a simple manufacturing method using this simple extruder This can reduce the manufacturing cost.

  Moreover, in FIG. 2 of patent document 1, the nozzle | cap | die which forms the outer peripheral surface shape of a cylindrical part, the metal core which forms the inner peripheral surface shape of a cylindrical part, and the metal core which forms the inner peripheral surface shape of a sealing part A tip mold formed from a hemispherical porous body provided at the tip, and an outer mold composed of a porous body provided so that the hemispherical concave surface forming the outer peripheral surface shape of the sealing portion opposes the opening of the die The sealing portion forming space composed of the tip of the porous body and the concave surface of the outer mold and the outside of the through hole provided inside the cored bar and the outer surface opposite to the concave surface of the outer mold, An extrusion molding machine capable of distribution is used. In this extrusion molding machine, first, air is sucked so that air flows from the side of the molding base forming the sealing portion filled in the extrusion molding machine, that is, from the sealing portion molding space to the inside of the core metal and the outside of the outer mold. In this state, the molding base is extruded into the sealing portion molding space in the extruder. Next, the outer mold is removed in a state where pressure is applied so that air flows from the outer direction of the outer mold toward the sealing portion molding space. Finally, pressure is applied so that air flows from the inside of the metal core toward the forming substrate forming the sealing portion through the tip die, thereby obtaining a one-end sealed cylindrical ceramic having a cylindrical portion of a desired length. .

Japanese Patent Laid-Open No. 01-225506

  By the way, in the one-end sealed cylindrical ceramics of FIG. 1 of Patent Document 1, when the outer mold is removed from the die in a state where the molding matrix is discharged from the outer mold through-hole, the molding matrix inside the through-hole is formed. A protrusion having a fractured surface is formed at the tip of the sealing portion by being physically broken while leaving a part of the sealing portion. Unlike the smooth surface structure other than the fracture surface of the cylindrical portion and the sealing portion, the fracture surface of the protrusion left on the sealing portion has a rough surface structure. Here, in general, the formation of a separation membrane on the surface of a ceramic porous substrate is affected by the surface structure of the substrate and the pore structure (porosity, average pore diameter) inside the substrate. If a part of the film is not smooth, uniform separation membrane formation is partially prevented in the part. For this reason, the one-end sealed cylindrical ceramic of FIG. 1 of Patent Document 1 cannot satisfactorily form a separation membrane around the protrusion formed on the sealing portion, and local leakage of the separation membrane occurs. Due to the fear, the performance of the entire separation membrane filter may be deteriorated. Further, in the one-end sealed cylindrical ceramics of FIG. 2 of Patent Document 1, a through hole is not formed in the outer mold, and a projection and a rough fracture surface of the surface structure are not formed in the sealed portion. When the molding substrate is pushed out into the sealing part molding space, a high pressure is locally applied with the vicinity of the tip of the sealing part being the highest, so that the tip of the sealing part has a dense pore structure as compared with the rest. For this reason, it is difficult to form a separation membrane satisfactorily at that portion, and the performance of the entire separation membrane filter may be deteriorated.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a single-side sealed cylindrical ceramic substrate for a separation membrane that suppresses the deterioration of the separation performance of the separation membrane filter. There is.

That is, the gist of the present invention is (a) a single-end-sealed cylindrical ceramic substrate for a separation membrane in which a separation membrane is formed on the outer surface, (b) a tubular portion and the tubular portion And a sealing portion having a portion having a surface structure or a pore structure different from that of the cylindrical portion, and having a fracture surface locally on the surface of the sealing portion. And (c) a glass layer having a coefficient of thermal expansion that is less than 2 × 10 ⁻⁶ / K with respect to the coefficient of thermal expansion of the porous ceramic substrate. Either directly on the surface of the sealing portion so as to cover the fracture surface or indirectly through a porous alumina ceramic layer mainly composed of alumina whose average pore diameter is smaller than that of the porous ceramic substrate. A dense layer mainly composed of the formed glass. It is in.

According to the single-end-sealed cylindrical ceramic substrate for separation membrane of the present invention, the opening is sealed by being fixed to the opening on one side of the cylindrical portion of the porous ceramic substrate, and the surface structure or fine structure is sealed to the cylindrical portion. A glass layer having a thermal expansion coefficient difference of less than 2 × 10 ⁻⁶ / K on the surface of the sealing portion having a part having a different pore structure, the thermal expansion coefficient difference of the porous ceramic base material being less than 2 × 10 ⁻⁶ / K. In addition, it is formed directly on the surface of the sealing portion so as to cover the fracture surface or indirectly through a porous alumina ceramic layer mainly composed of alumina whose average pore diameter is smaller than that of the porous ceramic base material. A dense layer mainly composed of glass is provided. For this reason, it becomes possible to form a uniform separation membrane having no defects over the entire surface of the single-end-sealed cylindrical ceramic substrate for separation membrane, and the separation membrane filter is significantly affected by the occurrence of local leakage of the separation membrane. It becomes possible to suppress degradation of the separation performance.

  Here, the sealing portion having a surface structure different from that of the cylindrical portion is, for example, a single-end sealed cylindrical shape for a separation membrane formed by integrally forming the cylindrical portion and the sealing portion by extrusion molding. In the ceramic substrate forming process, when the outer mold is removed, a projection formed by leaving a part of the molding substrate discharged from the through hole of the outer mold in the sealing portion, and the surface of the fracture surface of the projection The structure is rough with respect to the surface structure of the cylindrical portion formed smoothly by extrusion molding, and is evaluated by the surface roughness. The surface roughness is measured with an interference microscope, a laser microscope, or the like on the surface of the cylinder part and the sealing part of the target single-sided sealed ceramic ceramic substrate for separation membrane. In addition, the sealing portion having a pore structure different from that of the cylindrical portion is, for example, when the molding base is extruded into the sealing portion forming space in order to integrally form the sealing portion on one side of the cylindrical portion. In addition, if there is no escape place for the molding substrate, a high pressure is locally applied to the tip of the sealing portion, so that the tip of the sealing portion has a smaller porosity and a smaller average pore diameter than the cylindrical portion. It becomes a natural property.

  Preferably, the porous ceramic substrate has a multilayer structure. For this reason, for example, by forming a dense layer on the surface of the sealing portion of the porous ceramic base material having a multilayer structure in which the outer layer is more dense than the inner layer of the ceramic layer, the separation performance is improved as compared with the single layer. In addition, a single-end sealed cylindrical ceramic substrate for a separation membrane can be obtained.

  Preferably, the porous ceramic base material is formed mainly of any one of alumina, zirconia, mullite, silica, titania, silicon nitride, and silicon carbide. For this reason, there is provided a single-end sealed cylindrical ceramic substrate for a separation membrane that has an appropriate porosity to ensure the separation performance of the separation membrane filter and has sufficient mechanical strength to form a separation membrane. Can be provided.

Preferably, the difference between the thermal expansion coefficient of the porous ceramic base material and the thermal expansion coefficient of the dense layer containing glass as a main component is less than 1 × 10 ⁻⁶ / K. For this reason, during firing to form a dense layer mainly composed of glass on the surface of the sealing portion of the porous ceramic base material, cracking of the glass and peeling from the porous ceramic base material are suppressed. Therefore, it is possible to further suppress the deterioration of the performance of the separation membrane filter formed by forming the separation membrane on the single-end sealed cylindrical ceramic substrate for separation membrane.

Preferably, the composition of the glass is mainly composed of SiO ₂ and is composed of Al ₂ O ₃ , TiO ₂ , ZrO ₂ , ZnO, B ₂ O ₃ , Bi ₂ O ₃ , alkali metal, alkaline earth metal. One of them is included. The difference between the linear thermal expansion coefficient of the glass having such a composition and the linear thermal expansion coefficient of the porous ceramic base material can be adjusted to less than 2 × 10 ^−6. Separation from the base material is suppressed, and a single-end sealed cylindrical ceramic base material for a separation membrane that further suppresses performance deterioration of the separation membrane filter can be provided.

  Preferably, the porous ceramic base material is integrally formed by extrusion molding with the cylindrical portion and the sealing portion in a state where the opening of the die of the extrusion molding machine is closed by an outer mold having a through hole. Then, the fracture surface is locally formed on the surface of the sealing portion by removing the outer mold from the die. For this reason, the process of joining the cylinder part and sealing part of a porous ceramic base material becomes unnecessary. Thereby, it is possible to eliminate the occurrence of leakage of the fluid to be processed from the joined portion between the cylindrical portion and the sealing portion to the processed fluid, and to ensure the strength of the boundary between the cylindrical portion and the sealing portion. Can do.

  Preferably, the porous ceramic base material has the cylindrical portion and the sealing portion of the porous ceramic base material in a state where the opening of the die of the extruder is closed by an outer mold having a through hole. And by feeding, extruding, and joining ceramic forming raw materials of different properties separately inside the inner tube of the multiple tube provided with the inner tube and the outer tube, and between the inner tube and the outer tube. After being integrally formed by extrusion molding, the outer mold is removed from the die, whereby the fracture surface is locally formed on the surface of the sealing portion. The porous ceramic base material configured in this way has the separation performance of the separation membrane filter better than that of using a single layer porous ceramic base material by appropriately adjusting the porosity and average pore diameter of the multilayer structure. This can be further improved.

  Preferably, an opening is formed at an end of the porous ceramic substrate opposite to the sealing portion, an end surface of the end where the opening is formed, and an inner periphery adjacent to the end surface A dense layer similar to the dense layer containing glass as a main component is formed on the surface and the outer peripheral surface. For this reason, since the dense layer formed on the surface of the opening of the porous ceramic base material functions as a bonding agent, for example, the sealing member that seals the opening is bonded. At this time, it is not necessary to apply a tightening force to the opening side end portion, and it is possible to prevent damage to the one-side sealed cylindrical ceramic substrate for the separation membrane. In addition, when the difference between the thermal expansion coefficient of the porous ceramic base material and the thermal expansion coefficient of the dense layer is small, the porous ceramic base material It is possible to suitably prevent cracking of a dense body that causes leakage of gas or liquid at the joint with the sealing member, and the separation performance of the separation membrane filter can be further improved.

  Preferably, a cylindrical ceramic dense body is joined to an end of the porous ceramic base opposite to the sealing portion. In this way, the sealing member can be joined via the ceramic dense body without impairing the strength of the opening of the porous ceramic base material, and the tightening force can be increased when sealing with the sealing member. It becomes unnecessary to apply to the opening side end portion of the porous ceramic base material, thereby preventing the one-end sealed cylindrical ceramic base material for the separation membrane from being damaged.

It is a perspective view which shows the one end sealing type cylindrical ceramic base material for separation membranes of an example of this invention. It is sectional drawing on the plane which passes along the center of the single-sided sealing type cylindrical ceramic base material for separation membranes of FIG. It is a process chart of the single-sided sealing type cylindrical ceramic base material for separation membranes of FIG. FIG. 4 is a cross-sectional view of an extrusion molding machine and a molding substrate for explaining in detail a molding substrate filling process of the extrusion molding process P2 of FIG. 3. FIG. 4 is a cross-sectional view of a part of an extrusion molding machine and a molding substrate for explaining in detail an outer mold detachment process of the extrusion molding process P2 of FIG. 3. FIG. 4 is a cross-sectional view of a part of an extrusion molding machine and a molding base, which explain in detail a cylindrical portion extension step of the extrusion molding step P2 of FIG. 3. It is a SEM photograph which shows the surface state of the cylindrical part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of parts other than the protrusion of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the processus | protrusion of the sealing part of the porous ceramic base material of FIG. FIG. 1 and the glass composition of the glass layer formed on the outer surface of the sealing portion of the porous ceramic substrate in another embodiment of the present invention, the firing temperature at the time of coating the glass layer, and the linear thermal expansion coefficient of the glass layer. . It is a figure which shows the linear thermal expansion coefficient of the porous ceramic base material in FIG. 1 and the other Example of this invention. It is a figure explaining the sealing performance evaluation test of the glass layer formed in the sealing part of the porous ceramic base material in FIG. 1 and the other Example of this invention. The results of the sealing performance evaluation test of the glass layer coated on the porous ceramic substrate in FIG. 1 and other examples of the present invention and the difference in the linear thermal expansion coefficient between the porous ceramic substrate and the glass layer were carried out. It is the figure shown for every glass layer formed in the porous ceramic base material of an example. It is a SEM photograph which shows the surface state of the glass layer A formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer B formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer C formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer D formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer E formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer F formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface state of the glass layer G formed in the surface of the sealing part of the porous ceramic base material of FIG. It is a SEM photograph which shows the surface shape on the cylindrical part of the separation membrane formed into a film on the porous ceramic base material of FIG. 1 in which the glass layer is not formed in the surface of the sealing part. It is a SEM photograph which shows the surface shape on the processus | protrusion of the zeolite membrane formed into a film on the porous ceramic base material of FIG. 1 in which the glass layer is not formed in the surface of the sealing part. It is a SEM photograph which shows the film-forming state of the zeolite membrane in the boundary of the cyclic | annular end surface of the glass layer A of the single-sided sealing type cylindrical ceramic base material for separation membranes of FIG. 1 in which the glass layer A was formed on the surface of the sealing part. . It is sectional drawing on the plane which passes along the center of the porous ceramic base material of the two-layer structure in the other Example of this invention. It is sectional drawing on the plane which passes along the center of the porous ceramic base material of the two-layer structure in the other Example of this invention. FIG. 26 is a cross-sectional view of an extrusion molding machine and a molding substrate for explaining in detail an extrusion molding process of the porous ceramic substrate of FIG. 25. It is sectional drawing on the plane which passes along the center of the porous ceramic base material in the other Example of this invention. FIG. 28 is a cross-sectional view of the extrusion molding machine and the molding substrate for explaining in detail the molding substrate filling process of the extrusion molding process p2 of FIG. FIG. 28 is a cross-sectional view of an extrusion molding machine and a molding substrate for explaining in detail an outer mold detachment process of the extrusion molding process p2 of FIG. FIG. 28 is a cross-sectional view of an extrusion molding machine and a molding substrate for explaining in detail a cylindrical portion extension step of the extrusion molding step p2 of FIG. It is sectional drawing which shows the state in which the glass layer was formed in the surface of the opening side edge part of the porous ceramic base material in the other Example of this invention. It is sectional drawing which shows the state by which the ceramic dense body was joined to the opening side edge part of the porous ceramic base material in the other Example of this invention.

  Hereinafter, an example of a single-end-sealed cylindrical ceramic base material suitably used for the separation membrane filter of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a single-end sealed tubular ceramic substrate (hereinafter referred to as “tubular ceramic”) 10 for a separation membrane filter as an example of the present invention. FIG. 2 is a cross-sectional view on a plane passing through the center of the cylindrical ceramic 10 in the width direction. The cylindrical ceramic 10 has a cylindrical portion 12 having a circular cross section, a hemispherical outer peripheral surface and an inner peripheral surface that seal the opening at one end of the cylindrical portion 12, and forms a hemispherical internal space. The porous ceramic base material 16 which consists of the part 14 and the glass layer 18 which functions as a dense layer which coat | covers the outer surface of the sealing part 14 of the porous ceramic base material 16 are comprised. A protrusion 20 having a rough surface structure with a larger surface roughness than that of the cylindrical portion 12 having a smooth surface structure with a small surface roughness is formed at the tip of the sealing portion 14 of the porous ceramic substrate 16. The porous ceramic base material 16 is mainly composed of alumina (Al ₂ O ₃ ) having a particle size of 0.2 to 4.5 μm (average particle size 0.7 μm), and the cylindrical portion 12 and the sealing portion 14 are made of the above alumina. It has a single layer structure formed by The glass layer 18 is made of silicon dioxide (SiO ₂ ), Al ₂ O ₃ , TiO ₂ , zirconium dioxide (ZrO ₂ ), zinc oxide (ZnO), diboron trioxide (B ₂ O ₃ ), Bi ₂ O _3. The main component is alkali metal or alkaline earth metal. Further, the absolute value of the difference between the linear thermal expansion coefficient of the glass layer 18 and the linear thermal expansion coefficient of the porous ceramic substrate 16 is less than 2 × 10 ⁻⁶ / K.

Next, an example of the manufacturing process of the cylindrical ceramic 10 will be described with reference to the process chart of FIG. In the kneading step P1, an alumina (Al ₂ O ₃ ) powder having a particle size of 0.2 to 4.5 μm (average particle size of 0.7 μm), which is a main component of the porous ceramic base material 16, is molded, for example, with a methylcellulose binder. An auxiliary material and water are added, mixed and kneaded to adjust the molding substrate. In the extrusion molding step P2, a one-end sealed green molded body is obtained in which the molding base is extruded by an extruder and sealed on one side in the extrusion direction. In the drying and firing step P3, the single-end sealed green molded body is dried and then fired at 1250 ° C. for 2 hours, whereby a porous ceramic having a single layer structure having an average pore diameter of 0.15 μm and a porosity of 38% A substrate 16 is obtained. Next, in Step P4 to Step P7, a dense glass layer 18 is coated on the outer surface of the sealing portion of the porous ceramic base material 16 obtained in Step P3. First, a glass material such as silicon dioxide is mixed so as to have the same composition as the glass layer 18, and then melted and cooled to obtain a uniform glass. In the mixing step P4, a solvent such as toluene and water and, if necessary, an organic binder, a dispersant, and an antifoaming agent are added to a glass frit having an average particle diameter of 1 to 5 μm obtained by pulverizing the glass, followed by stirring. The glass slurry is adjusted by mixing. In the dipping step P5, the sealing portion 14 of the porous ceramic base material 16 is dipped in the glass slurry for 10 seconds and then pulled up. In the drying step P <b> 6, the immersed porous ceramic substrate 16 is naturally dried for 1 hour, for example, and the outer peripheral surface of the sealing portion of the porous ceramic substrate 16 is covered with the glass frit constituting the glass layer 18. In the firing step P7, the porous ceramic base material 16 that has undergone the process P6 is fired at 800 ° C. to 950 ° C. for 1 hour, and the outer peripheral surface of the sealing portion 14 of the porous ceramic base material 16 is melted with the glass frit. The cylindrical ceramics 10 covered with the layer 18 is obtained.

  Next, a forming body filling step, an outer die detaching step, and a cylindrical portion extending step in the extrusion molding step P2 for forming a one-end sealed cylindrical green molded body that is fired to become the porous ceramic substrate 16 are performed. This will be described in detail with reference to FIGS. 4, 5, and 6. As shown in FIG. 4, an extrusion molding machine 22 for extruding a one-end sealed cylindrical green molded body includes a die 24 that forms the outer peripheral surface shape of the cylindrical portion 12 of the porous ceramic substrate 16, and A core metal 26 that is installed at a predetermined position inside the base 24 and forms the inner peripheral surface shape of the cylindrical portion 12, and a hemispherical portion 28 that forms the inner peripheral surface shape of the sealing portion 14 are provided at the tip. A piston 30 slidably provided inside the metal 26 and a hemispherical concave portion 32 forming the outer peripheral surface shape of the sealing part 14 are detachably provided on the base 24 so as to oppose the opening of the base 24. The molded body P thus extruded is constituted by an outer mold 36 having a through hole 34 in the recess 32 through which the molded body P is discharged from the sealing portion molding space 33 to the outside. The piston 30 includes an air hole 40 through which air pressure is supplied from the inner space of the core metal 26, and air pressure is supplied from the inside of the core metal 26 through the air hole 40, so that the hemispherical portion 28 of the piston 30 becomes the core metal 26. It is slidably provided inside the cored bar 26 so as to be pushed away from the core. The cored bar 26 includes a stepped part 42 formed so that the opening side end of the base 24 protrudes toward the inside of the cored bar 26, and the end of the piston 30 opposite to the hemispherical part 28. A stopper 44 provided on the piston 30 abuts against the step portion 42 to restrict the sliding of the piston 30. In the molding substrate filling process, the molding substrate P is moved in the direction of the arrow in the direction of the arrow until a part of the molding substrate P is discharged from the sealing portion molding space 33 to the outside of the extruder 22 through the through hole 34 of the outer mold 36. Extruded and filled. Next, in the outer mold removing step shown in FIG. 5, the outer mold 36 is removed from the base 24. At this time, the molding base P inside the through hole 34 is physically broken while leaving a part of the molding base P forming the sealing portion 14, whereby the projection 20 having a fracture surface at the tip of the sealing portion 14. Is formed. Note that the protrusion 29 may not be formed depending on the location where physical breakage occurs, but in any case, a fracture surface having a rougher surface structure than the cylindrical portion 12 is formed at the tip of the sealing portion 14. Finally, in the cylindrical portion extending step shown in FIG. 6, air is supplied from the inside of the core metal 26, and the hemispherical portion 28 of the piston 30 is slid away from the core metal 26 to form the sealing portion 14. By extruding the forming base P to be taken, the forming base P for forming the cylindrical portion 12 is extended. Through the extrusion process P2 described above, the cylindrical portion 12 and the sealing portion 14 of the porous ceramic base material 16 are integrally formed, and in the subsequent steps, are integrally fixed to the opening on one side of the cylindrical portion to seal the opening. A glass layer 18 is formed on the outer surface of the sealing portion to form a one-end sealed cylindrical ceramic 10.

  In this way, the cylindrical portion and the sealing portion are integrally formed by the extruder 22 and the surface structure of the porous ceramic base material 16 obtained through the drying and firing step P3 is magnified 500 times with a scanning electron microscope (SEM). Observed. FIG. 7 is an SEM photograph showing the surface structure of the cylindrical portion 12 of the cylindrical ceramic 10, and FIG. 8 is an SEM photograph showing the surface structure of a portion other than the protrusion 20 of the sealing portion 14 of the cylindrical ceramic 10. FIG. 9 is an SEM photograph showing the surface structure of the protrusion 20 of the sealing portion 14 of the cylindrical ceramic 10. As shown in FIGS. 7 and 8, the surface structure of the cylindrical portion 12 and the portion other than the protrusion 20 of the sealing portion 14 is smooth. On the other hand, as shown in FIG. 9, the protrusion 20 of the sealing portion 14 is physically broken when the molding base P discharged from the through hole 34 of the outer mold 36 is removed from the base 24. Compared to the cylindrical portion 12, it is not smooth. For this reason, from the non-smoothness compared with the projection 20 which is a part of the sealing portion 14 of the porous ceramic substrate 16 and the cylindrical portion 12 of the surface structure of the projection 20, the outer surface of the porous ceramic substrate 16 When forming a separation membrane, uniform film formation is locally hindered by the protrusions 20, and when used as a base material for a separation membrane filter, there is a possibility that degradation of separation performance may occur. Therefore, a glass layer 18 is formed on the outer peripheral side surface of the sealing portion 14 in the cylindrical ceramic 10 so as to cover the protrusions 20 of the porous ceramic base material 16.

Cylindrical ceramics 10 configured in this manner has, for example, silicon dioxide (SiO ₂ ), Al ₂ O ₃ , TiO ₂ , zirconium dioxide (ZrO ₂ ) shown in FIG. Since the glass layer 18 mainly composed of zinc oxide (ZnO), diboron trioxide (B ₂ O ₃ ), Bi ₂ O ₃ , alkali metal, and alkaline earth metal is formed, the cylindrical ceramic 10 It is possible to form a uniform separation membrane having no defects on the surface, and it is possible to suppress a significant deterioration in separation performance of the separation membrane filter due to occurrence of a local separation membrane leak or the like. Moreover, since the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layer 18 is less than 2 × 10 ⁻⁶ / K, the firing step P7 at 800 ° C. to 950 ° C. In this case, the crack of the glass layer 18 and the peeling of the glass layer 18 from the inner peripheral surface of the porous ceramic substrate 16 do not occur. For this reason, the fall of the separation performance of a separation membrane filter is suppressed further.

  Subsequently, a test conducted by the present inventors in order to verify the effect of the glass layer 18 coated on the outer peripheral side surface of the sealing portion 14 of the cylindrical ceramic 10 will be described in detail with reference to FIGS. 10 to 23. To do.

  First, in order to evaluate the sealing performance of the glass layer 18 formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16, glass that covers the outer surface of the sealing portion 14 of the porous ceramic base material 16. Cylindrical ceramics to be subjected to a sealing property evaluation test with various compositions were prepared as follows. First, the glass frit of the glass G from the glass A which coat | covers the outer surface of the sealing part 14 of the porous ceramic base material 16 was adjusted. That is, the glass A having an average particle diameter of 1 to 5 μm is pulverized by mixing, melting, and homogenizing the glass raw materials in advance so that the glass compositions of glass A to G as shown in FIG. 10 are obtained. To glass frit having each composition of glass G. After immersing the sealing portion 14 of the porous ceramic base material 16 in the dip step P5 for 10 seconds in the glass slurry of glasses A to G prepared by the same method as the mixing step P4 using the glass frit, The said baking process P7 was performed by the drying process P6 and the baking temperature at the time of the coating of each glass of Glass A to G shown by FIG. Through these steps, cylindrical ceramics for use in a sealing test in which the sealing portion 14 of the porous ceramic base material 16 mainly composed of alumina was coated with the glasses A to G were produced.

  The linear thermal expansion coefficients of the glass layers A to G covering the outer surface of the sealing portion 14 of the produced porous ceramic substrate 16 of the cylindrical ceramic were measured as follows. The glass frit of each of the glasses A to G was formed into a cylindrical shape having a diameter of about 5 mm and a length of 10 to 20 mm and then baked to form a glass test piece. The produced glass test piece was subjected to a differential thermal dilatometer (manufactured by TMA8310 Rigaku), the average linear thermal expansion coefficient of 30 ° C. to 500 ° C. was measured by the compression load method of the glass test piece, and the linear heat from glass A to G The expansion coefficient was evaluated as shown in FIG.

  Moreover, the linear thermal expansion coefficient of the produced porous ceramic base material 16 of the cylindrical ceramic was measured as follows. The main component is alumina having a particle size of 0.2 to 4.5 μm (average particle size 0.7 μm) from which the porous ceramic substrate 16 is formed by the kneading step P1, the extrusion step P2 and the drying and firing step P3. Cylindrical porous ceramic test pieces having an outer diameter of 5 mm, an inner diameter of 3 mm, and a length of 10 to 20 mm were produced. The produced porous ceramic test piece is subjected to a differential thermal dilatometer (manufactured by TMA8310 Rigaku), and the average linear thermal expansion coefficient of the porous ceramic test piece is measured from 30 ° C. to 500 ° C. by the compression load method. The linear thermal expansion coefficient of the material 16 was evaluated as shown in FIG.

FIG. 12 is a diagram for explaining a sealing property evaluation test of glass layers A to G formed on the sealing portion 14 of the porous ceramic base material 16 made of cylindrical ceramics. The outer surface other than the sealing portion 14 is covered with an epoxy resin, and an epoxy resin 50 is used by using a stainless steel jig 48 into which an opening at the end opposite to the sealing portion 14 is inserted. The cylindrical ceramics sealed with was installed in the pressure vessel 52 in a state where the opening at one end of the stainless steel tube 46 was kneaded with the outside of the pressure vessel 52. At room temperature, nitrogen (N ₂ ) gas is pressurized at 0.4 MPa from the outer surface of the cylindrical ceramic so that the differential pressure from the external pressure becomes 0.3 MPa, passes through the inside of the stainless steel tube 46, and goes out of the pressure vessel 52. The sealing performance was evaluated by measuring the amount of N ₂ gas leak.

FIG. 13 shows the result of the above-described sealing property evaluation test for the glass layers A to G of the cylindrical ceramics and the difference in the linear thermal expansion coefficient between the porous ceramic base material 16 and the glass layer. It is the figure shown for every glass layer. The lower row is the absolute value of the difference in linear thermal expansion coefficient (× 10 ⁻⁶ / K) at 500 ° C. of each glass layer composed of the porous ceramic substrate 16 and the glasses A to G, that is, the glass of FIG. The absolute value of the difference of the linear thermal expansion coefficient of the glass layer of A to G and the linear thermal expansion coefficient of the porous ceramic base material 16 of FIG. 11 is shown. In the upper part, a circle indicates that no gas leak has occurred, while a cross indicates that a gas leak has occurred.

  Moreover, the surface state of the glass layer of the cylindrical ceramics glass A to G used for the said sealing property evaluation test was observed by SEM. FIG. 14 is an SEM photograph showing the surface state of the glass layer of cylindrical ceramics in which the outer surface of the sealing portion 14 is covered with the glass layer of glass A. Similarly, each of FIGS. 15 to 20 shows the cylindrical ceramics in which the sealing portion 14 is covered with the glass layers of glass B, glass C, glass D, glass E, glass F, and glass G, respectively. It is a SEM photograph which shows the surface state of this glass layer.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficients required for the cylindrical ceramic 10 and the porous ceramic base material 16 having a linear thermal expansion coefficient at 500 ° C. of 7.1 × 10 ⁻⁶ / ° C. is 2 The outer surface of the sealing portion 14 of the porous ceramic substrate 16 is formed by the glass layers 18 of glass A, B, C, D, and F having a linear thermal expansion coefficient that is smaller than 0.0 × 10 ⁻⁶ / ° C. In the coated cylindrical ceramic 10, no gas leak was observed. On the surface of the glass layer 18 of the cylindrical ceramics 10 in which the glass A, B, C, D, and F in which no gas leak was observed were formed on the outer surface of the sealing portion 14, cracks and the like causing gas leak were observed. Was not. On the other hand, the absolute value of the difference in linear thermal expansion coefficient required for the cylindrical ceramic 10 and the porous ceramic substrate 16 having a linear thermal expansion coefficient at 500 ° C. of 7.1 × 10 ⁻⁶ / ° C. is 2.0. In the cylindrical ceramic in which the outer surface of the sealing portion 14 of the porous ceramic substrate 16 is covered with a glass layer of glass E and G having a linear thermal expansion coefficient that does not satisfy the condition of less than × 10 ⁻⁶ / ° C. A gas leak was observed. Innumerable cracks that cause gas leakage were observed on the surface of the glass layer of cylindrical ceramics on which the glass E and G in which these gas leaks were observed were formed on the outer surface of the sealing portion 14. From the above results, in the firing step P7 at a firing temperature of 800 ° C. to 950 ° C., a glass layer as a dense layer is formed on the outer surface of the sealing portion 14 of the porous ceramic substrate 16 while ensuring sealing properties. Therefore, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic base material 16 and the linear thermal expansion coefficient of the glass layer 18 needs to be smaller than 2.0 × 10 ⁻⁶ / ° C. Since the internal stress that acts on the glass layer and causes cracks on the surface thereof increases as the absolute value of the difference in linear thermal expansion coefficient increases, more preferably, the linear heat of the porous ceramic substrate 16 It is desirable that the absolute value of the difference between the expansion coefficient and the linear thermal expansion coefficient of the glass layer 18 is less than 1.0 × 10 ⁻⁶ / ° C.

Subsequently, in order to evaluate whether the separation membrane is satisfactorily formed on the cylindrical ceramic 10 by the glass layer 18 formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16, the cylindrical ceramic 10 A test was conducted to evaluate the separation performance of a separation membrane filter formed by forming a separation membrane. First, as a separation membrane substrate on which a separation membrane is formed, a porous ceramic substrate 16 having a glass layer formed on the outer surface of the sealing portion, and an outer surface of the sealing portion 14 of the porous ceramic substrate 16 A cylindrical ceramic 10 having a glass layer 18 of glass A formed thereon and a cylindrical ceramic porous substrate having both ends opened without being sealed by a sealing portion were prepared. The cylindrical ceramic porous substrate is formed by extrusion molding a kneaded material mainly composed of alumina having a particle size of 0.2 to 4.5 μm (average particle size of 0.7 μm), which is the same raw material as the porous ceramic substrate 16. After forming into a cylindrical shape by a machine, it was produced by drying and firing. Next, these three types of separation membrane substrates were immersed in a suspension (1.8 g / L) obtained by pulverizing MOR type zeolite seed crystals (HSZ-600H0A, manufactured by Tosoh Corporation). The separation membrane substrate carrying the zeolite seed crystals was allowed to stand for 20 minutes or more at room temperature, and then dried at 70 ° C. for 20 minutes. Next, these separation membrane substrates were immersed in a reaction synthesis solution (SiO ₂ : Al ₂ O ₃ : Na ₂ O: H ₂ O = 3600: 15: 1000: 96000 (mol composition)), 180 By performing hydrothermal synthesis at 6 ° C. for 6 hours, a zeolite membrane was formed on the outer surface of the porous ceramic substrate 16, the cylindrical ceramic 10, and the cylindrical porous substrate. The above three kinds of separation membrane substrates on which zeolite membranes were formed were boiled and washed with pure water, and then dried at 110 ° C. for 3 hours to obtain a separation membrane filter for use in a separation membrane performance evaluation test.

  The separation membrane filter was subjected to an acetic acid / water vapor permeation test (VP test) under the following conditions to evaluate the performance of the separation membrane.

[Test conditions]
・ Membrane area: 6.3 × 10 ⁻⁴ m ²
・ Acetic acid / water = 77wt% / 23wt%
-Reaction temperature: 125 ° C

  Further, the separation factor was determined according to the following formula. (Water / acetic acid) separation factor = (permeate side water concentration / permeate side acetic acid concentration) / (supply side water concentration / supply side acetic acid concentration). It is shown that the larger the separation factor, the higher the separation performance of the zeolite separation membrane, that is, acetic acid is not permeated by the separation membrane and only water is permeated.

  In addition, the surface state of the zeolite membrane formed on the porous ceramic substrate 16 subjected to the acetic acid / water vapor permeation test was observed by SEM at a magnification of 3000 times. FIG. 21 is a SEM photograph showing the surface shape of the zeolite membrane formed on the cylindrical portion 12, and FIG. 22 shows the surface shape of the zeolite membrane on the protrusion 20 formed at the tip of the sealing portion 14. It is a SEM photograph. Moreover, the film formation state of the zeolite membrane near the boundary of the glass layer 18 of the glass A of the cylindrical ceramics 10 subjected to the acetic acid / water vapor permeation test was observed by SEM. FIG. 23 shows the vicinity of the annular end surface of the glass layer 18 formed on the outer surface of the porous ceramic substrate 16 of the cylindrical ceramic 10 subjected to the acetic acid / water vapor permeation test in the longitudinal direction of the porous ceramic substrate 16. It is sectional drawing cut | disconnected and shown.

  As a result of the acetic acid / water vapor permeation test, the separation factor of the separation membrane filter in which the zeolite membrane was formed on the porous ceramic base material 16 on which the glass layer was not formed on the outer surface of the sealing portion 14 was 25, cylindrical The separation factor of the separation membrane filter in which the zeolite membrane was formed on the ceramic 10 was 23000, and the separation factor of the cylindrical ceramic porous substrate in which the openings at both ends were not sealed was 25000. The zeolite membrane on the cylindrical portion 12 of the separation membrane filter using the porous ceramic substrate 16 having a small separation coefficient as the separation membrane substrate is uniformly formed as shown in FIG. The zeolite membrane on the 14 projections 20 is not uniformly formed as shown in FIG. Therefore, in the porous ceramic base material 16 in which the glass layer is not formed on the outer surface of the sealing portion 14, the protrusion is formed at the tip of the sealing portion 14, and the surface structure of the protrusion is a cylindrical portion. However, the cylindrical ceramic 10 has a protrusion of the sealing portion 14 while the uniform zeolite membrane cannot be formed, and the performance of the separation membrane filter is deteriorated due to local leakage of the separation membrane. Since 20 was covered with the glass layer 18 of glass A, it was shown that the zeolite membrane was uniformly formed and the decrease in the separation performance of the separation membrane filter was suppressed. Further, as shown in FIG. 23, a uniform zeolite membrane is continuously formed on the annular end face of the glass layer 18 of the glass A, that is, at the boundary between the glass layer 18 and the porous ceramic base material 16, and the porous ceramic base is formed. It was shown that the formation of the glass layer 18 on the sealing portion 14 of the material 16 has a small influence on the formation of a uniform zeolite film.

  As described above, according to the cylindrical ceramic 10 of the present embodiment, the opening is sealed by being fixed to the opening on one side of the cylindrical portion 12 of the porous ceramic base material 16, and the surface structure has a surface structure with respect to the cylindrical portion 12. A dense glass layer 18 is formed on the surface of the sealing portion 14 on which the protrusions 20 having different fracture surfaces are formed. For this reason, it becomes possible to form a uniform separation membrane having no defects on the surface of the cylindrical ceramic 10, and to suppress a significant deterioration in separation performance of the separation membrane filter due to the occurrence of a local separation membrane leak or the like. It becomes possible.

  Further, according to the present embodiment, the porous ceramic substrate 16 is formed with alumina as a main component. For this reason, it is possible to provide the cylindrical ceramics 10 having an appropriate porosity for ensuring the separation performance of the separation membrane filter and sufficient mechanical strength for forming the separation membrane.

  Further, according to the present embodiment, the dense layer that covers the outer surface of the sealing portion 14 of the cylindrical ceramic 10 is the glass layer 18 mainly composed of glass. For this reason, the sealing property and corrosion resistance of the glass layer 18 can provide the one-end-sealed porous ceramic substrate 10 that can be applied to a separation membrane filter that can be used even under highly acidic or highly alkaline conditions.

Further, according to this example, the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layer 18 is less than 2 × 10 ⁻⁶ / K, preferably 1 × 10 ^−6. / K. For this reason, in the firing step P7 for forming the glass layer 18 on the outer surface of the sealing portion 14 of the porous ceramic base material 16, cracking of the glass layer 18 and peeling from the porous ceramic base material 16 are suppressed. Therefore, it is possible to further suppress the performance deterioration of the separation membrane filter formed by forming the separation membrane on the cylindrical ceramic 10.

In addition, according to the present embodiment, the composition of the glass layer 18 is SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , ZnO, B ₂ O ₃ , Bi ₂ O ₃ , alkali metal, alkaline earth metal. The main component. The difference between the linear thermal expansion coefficient of the glass layer 18 having such a composition and the linear thermal expansion coefficient of the porous ceramic base material 16 can be adjusted to less than 2 × 10 ⁻⁶ , and thus the glass layer 18 in the firing step P7. The cylindrical ceramics 10 can be provided in which cracking of the ceramics and peeling from the porous ceramic base material 16 are suppressed, and performance degradation of the separation membrane filter is further suppressed.

  Further, according to the present embodiment, the cylindrical ceramic 10 is formed by integrally forming the cylindrical portion 12 and the sealing portion 14 of the porous ceramic base material 16 by extrusion molding. For this reason, the process of joining the cylindrical part 12 and the sealing part 14 of the porous ceramic base material 16 becomes unnecessary. Thereby, it is possible to eliminate the occurrence of leakage of the fluid to be processed from the joint portion between the cylindrical portion 12 and the sealing portion 14 to the processed fluid, and the strength of the boundary between the cylindrical portion 12 and the sealing portion 14. Can be secured.

  Next, another embodiment of the present invention will be described. In the following embodiments, parts that are substantially the same as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The cylindrical ceramic 10 of this example is the same as the manufacturing steps P1 to P7 of Example 1 described above, except that the particle size of alumina, which is the main component of the raw material used, and the firing temperature after extrusion are different. Formed with. That is, a molding substrate prepared by adding a molding aid such as a methyl cellulose binder and water to alumina having a particle size of 0.7 to 1.4 μm (average particle size of 3.0 μm) and mixing and kneading is extruded. It was put into a molding machine 22 and extruded to obtain a single-end sealed cylindrical green molded body similar to the porous ceramic substrate 16 of FIG. The single-end-sealed cylindrical green molded body is dried and then fired at 1400 ° C. for 2 hours to obtain a porous ceramic substrate 16 having a single layer structure with an average pore diameter of 0.8 μm and a porosity of 40%. . In the mixing step P4 to the firing step P7, the glass layer 18 is formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 to constitute the cylindrical ceramic 10 of the present embodiment.

  In order to evaluate the sealing performance of the glass layer 18 formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 of the cylindrical ceramic 10, the glass A to G glass is formed in the same manner as in the above-described embodiment. The cylindrical ceramics in which the sealing portion 14 was covered with a layer was subjected to a sealing property evaluation test. Further, the linear thermal expansion coefficient of the porous ceramic substrate 16 from 30 ° C. to 500 ° C. was measured by the same method as described above. The linear thermal expansion coefficient of the porous ceramic substrate 16 is shown in FIG. 11, and the results of the sealing evaluation test are shown in FIG.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layers 18 of the glass A, B, C, D and F is 2.0 × 10 ⁻⁶ / In the cylindrical ceramic 10 having a temperature lower than 0 ° C., no gas leak was observed, and no cracks causing gas leak were observed on the surface of the glass layer 18 (not shown). On the other hand, in the case of cylindrical ceramics in which the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficients of the glass layers E and G is 2.0 × 10 ⁻⁶ / ° C. or more. Gas leakage was observed, and numerous cracks were observed on the surface of the glass layer (not shown).

  As described above, according to the cylindrical ceramic 10 of the present embodiment, the same effects as those of the first embodiment can be obtained.

Further, according to this example, the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layer 18 is less than 2 × 10 ⁻⁶ / K, preferably 1 × 10 ^−6. / K. For this reason, in the firing step P7 for forming the glass layer 18 on the outer surface of the sealing portion 14 of the porous ceramic base material 16, cracking of the glass layer 18 and peeling from the porous ceramic base material 16 are suppressed. Therefore, it is possible to further suppress the performance deterioration of the separation membrane filter formed by forming the separation membrane on the cylindrical ceramic 10.

  Next, another embodiment of the present invention will be described. FIG. 24 is a sectional view on a plane passing through the center of the two-layered cylindrical ceramic 54. The cylindrical ceramic 54 is mainly composed of an inner layer 56 similar to the porous ceramic base material 16 of the above-described Example 2, and alumina having an average pore diameter formed on the outer surface thereof smaller than that of the porous ceramic base material 16. An outer surface corresponding to a part of the outer layer 58 formed on the outer surface of the sealing portion 14 of the inner layer 56 of the porous ceramic substrate 60 of the two-layer structure. And a glass layer 18 formed on the substrate. The porous ceramic substrate 60 of the cylindrical ceramic 54 is obtained as follows. First, a particle size of 0.2 to 4.5 μm (average particle size) of the porous ceramic substrate 16 of Example 2 having an average pore size of 0.8 μm and a porosity of 40% so that the sealing portion 14 is on the lower side. 0.7 μm) of alumina, an organic binder, and water and water were mixed and stirred for 30 seconds in a slurry of alumina particles prepared by stirring. Thereafter, the porous ceramic substrate 16 in which the slurry is uniformly coated as a cake layer is dried and fired at 1250 ° C. for 2 hours, whereby alumina having an average pore diameter of 0.15 μm and a porosity of 38% is the main component. A porous ceramic substrate 60 having a two-layer structure in which the porous film to be formed is formed as the outer layer 58 is obtained. In the mixing step P4 to the firing step P7, the glass layer 18 is formed on a part of the outer layer 58 corresponding to the outer surface of the sealing portion 14 of the inner layer 56 of the porous ceramic base material 60, thereby forming the cylindrical ceramic 54. .

  In order to evaluate the sealing performance of the glass layer 18 formed on the outer surface of the outer layer 58 corresponding to the outer surface of the sealing portion 14 of the inner layer 56 of the porous ceramic substrate 60 of the cylindrical ceramic 54, The cylindrical ceramics 54 in which the outer surface of the outer layer 58 was covered with glass layers A to G in the same manner as in No. 2 was subjected to a sealing performance evaluation test. Moreover, the linear thermal expansion coefficient of 30 to 500 ° C. of the porous ceramic substrate 60 having a two-layer structure was measured by the following method. That is, the main component is alumina having a particle size of 0.7 to 1.4 μm (average particle size of 3.0 μm), which is a raw material of the porous ceramic substrate 16 of Example 2, and a cylindrical shape having an outer diameter of 5 mm and an inner diameter of 3 mm. Porous ceramics are prepared and immersed in a slurry whose main component is alumina having a particle size of 0.2 to 4.5 μm (average particle size 0.7 μm), dried, and fired to obtain an outer diameter of 5 mm, an inner diameter of 3 mm, and a length. A two-layer cylindrical test piece having a thickness of 10 to 20 mm was prepared, and the obtained test piece was subjected to a suggested thermal dilatometer to evaluate the linear thermal expansion coefficient of the porous ceramic substrate 60 as shown in FIG. did. Moreover, the result of a sealing property evaluation test is shown in FIG.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 60 and the linear thermal expansion coefficient of the glass layers 18 of glass A, B, C, D, and F is 2.0 × 10 ⁻⁶ / In the cylindrical ceramic 54 having a temperature lower than 0 ° C., no gas leak was observed, and no cracks causing gas leak were observed on the surface of the glass layer 18 (not shown). On the other hand, in the case of cylindrical ceramics in which the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 60 and the linear thermal expansion coefficients of the glass layers E and G is 2.0 × 10 ⁻⁶ / ° C. or more. Gas leakage was observed, and numerous cracks were observed on the surface of the glass layer (not shown).

  As described above, according to the cylindrical ceramics 54 of the present embodiment, the same effects as those of the first and second embodiments can be obtained.

  Further, according to the present embodiment, the porous ceramic substrate 60 of the cylindrical ceramic 54 has a two-layer structure of the inner layer 56 and the dense outer layer 58 having an average pore diameter smaller than that of the inner layer. Since the dense glass layer 18 is formed on a part of the outer surface of the outer layer 58 corresponding to the outer side of the sealing portion 14 of the inner layer 56 of the cylindrical ceramic 54, the separation performance is higher than that of the single-layered cylindrical ceramic. An improved cylindrical ceramic 54 can be obtained.

  Next, another embodiment of the present invention will be described. FIG. 25 is a sectional view on a plane passing through the center in the width direction of the cylindrical ceramics 62 having a two-layer structure. The cylindrical ceramic 62 includes a cylindrical portion 64 and a sealing portion 66 that seals an opening on one side of the cylindrical portion 64, and an inner layer 70 that is a porous ceramic whose main component is alumina, and a cylinder similar to the inner layer 70. Formed on the outer surface of the sealing portion 74 of the outer layer 78 and the porous ceramic base material 80 having a two-layer structure including a portion 72, a sealing portion 74, and an outer layer 78 whose main component is porous ceramics of alumina. And a glass layer 18. Further, the cylindrical portion 64 and the cylindrical portion 72 have a fractured surface having a different surface structure, and are respectively cylindrical with the inner layer 70 inward from the tip of the sealing portion 66 of the inner layer 70 and the tip of the sealing portion 74 of the outer layer 78. A protrusion 81 is formed at the tip of the sealing portion 74 of the outer layer 78 so as to protrude in a direction away from the portion 64 and the cylindrical portion 72.

The cylindrical ceramic 62 is configured as follows. First, alumina (100 mol%) having a particle size of 15 to 50 μm (average particle size 35 μm) and kaolinite (Al ₂ Si ₂ O ₅ (OH) ₄ ) (3.1 mol) having an average particle size of 0.6 μm as a sintering aid. %) And yttria (Y ₂ O ₃ ) (1.3 mol%) having an average particle diameter of 0.5 μm are added and mixed, and a methyl cellulose binder and water as a forming aid and water are added and kneaded in a kneader, A was obtained. Similarly, a sintering aid was added to and mixed with alumina having an average particle size of 7.0 μm, and methyl cellulose binder and water were added as a molding aid and kneaded with a kneader to obtain a molding base B. Next, a forming substrate A for the inner layer 70 and a forming substrate B for the outer layer 78 of the porous ceramic substrate 80 are supplied to an extruder 82 that integrally forms a porous ceramic substrate having a two-layer structure by extrusion. To obtain a two-layer structure single-end sealed green molded body. The obtained two-layer structure single-end sealed green molded body was dried and fired at 1450 ° C. for 2 hours, whereby an average pore diameter of 1. on the outer surface of the inner layer 70 having an average pore diameter of 9.3 μm and a porosity of 40%. A porous ceramic substrate 80 having a two-layer structure in which an outer layer 78 having a pore size of 4 μm and a porosity of 40% was formed. In the mixing step P4 to the firing step P7, the glass layer 18 is formed on the outer surface of the sealing portion 74 of the outer layer 78 of the porous ceramic base material 80, thereby forming the cylindrical ceramic 62.

  FIG. 26 is a cross-sectional view of the extrusion molding machine 82, the molding base A, and the molding base B for explaining in detail the extrusion process of the porous ceramic substrate 80 of the cylindrical ceramic 62. The extrusion molding machine 82 is provided on the upstream side in the extrusion direction of the molding base A and the molding base B indicated by arrows in FIG. 26, and the molding base A and the inner and outer cylinders for forming the inner layer 70 inside the inner cylinder. And a double pipe (not shown) of the inner cylinder and the outer cylinder into which each of the molding base B forming the outer layer 78 is inserted, and the outer side of the cylindrical portion 72 of the outer layer 78 provided on the downstream side in the extrusion direction. A longitudinal member having a hemispherical portion 85 at one end, which forms a base 84 having a single tube forming the surface, and an inner surface of the cylindrical portion 64 of the inner layer 70 and an inner surface of the sealing portion 66 of the inner layer 70 The metal core 86 set inside the single tube of the base 84, the hemispherical concave portion 32 forming the outer surface of the sealing portion 74 of the outer layer 78, and the extruded molding base A and molding base B are extruded. A through hole 34 for discharging to the outside of the molding machine 82 , Composed of the outer mold 36. which the recess 32 is detachably attached so as to oppose to the opening of the mouthpiece 84. When the molding base A is extruded in the direction of the arrow in FIG. 26 between the inner cylinder and the outer cylinder, the molding base A is molded inside the inner cylinder of the double pipe of the base 84 of the extrusion machine 82. Cylindrical portions 64 and 72 of the inner layer 70 and the outer layer 78 having a double layer structure with the substrate B on the outside are formed between the core metal 86 and the single tube of the base 84. Further, when the molding base A and the molding base B are extruded, the sealing base 66 and the outer layer 78 of the inner layer 70 are formed with the molding base B facing outside between the hemispherical portion 85 of the core metal 86 and the concave portion 32 of the outer die 36. The sealing portion 74 is formed, and the molding base A and the molding base B are discharged to the outside of the extrusion molding machine 82 through the through hole 34 of the outer mold 36 as they are. When the outer mold 36 is removed from the base 84 in this state, the molding base A and the molding base B that have been pushed into the through-hole 34 are broken in the middle, and the inner layer with respect to the molding base B that forms the outer layer 78 is formed. Projections 81 projecting from the respective tips of the sealing portion 66 of the inner layer 70 and the sealing portion 74 of the outer layer 78 are formed with the molding base A forming the 70 inside. In the fracture surface of the protrusion 81, the molding base A and the molding base B appear on the surface, and the surface structure is rough and not smooth as compared with the cylindrical portion 78 of the outer layer. In this way, the molding base A and the molding base B having different properties are supplied to the inside of the inner cylinder of the double pipe of the base and between the inner cylinder and the outer cylinder, respectively, are extruded and merged and integrated in the extruder 82. As a result, a one-end sealed cylindrical green molded body having a two-layer structure is obtained.

  In order to evaluate the sealing property of the glass layer 18 formed on the outer surface of the sealing portion 74 of the outer layer 78 of the porous ceramic base material 80 of the cylindrical ceramic 62, the same method as in Examples 1 to 3 described above was used. The cylindrical ceramics 62 in which the outer surface of the outer layer 78 was covered with the glass layers A to G was subjected to a sealing property evaluation test. Moreover, the linear thermal expansion coefficient of 30 to 500 ° C. of the porous ceramic substrate 80 having a two-layer structure was measured by the following method. That is, using a forming substrate A as an inner layer and a forming substrate B as an outer layer, a two-layer cylindrical test piece having an outer diameter of 5 mm, an inner diameter of 3 mm, and a length of 10 to 20 mm was produced, and the obtained test piece was suggested as a thermal dilatometer. The linear thermal expansion coefficient of the porous ceramic substrate 80 was evaluated as shown in FIG. Moreover, the result of a sealing property evaluation test is shown in FIG.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 80 and the linear thermal expansion coefficient of the glass layers 18 of glass A, B, C, D and F is 2.0 × 10 ⁻⁶ / In the cylindrical ceramic 62 having a temperature lower than 0 ° C., no gas leak was observed, and no cracks causing gas leak were observed on the surface of the glass layer 18 (not shown). On the other hand, in the case of cylindrical ceramics in which the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 80 and the linear thermal expansion coefficients of the glass layers E and G is 2.0 × 10 ⁻⁶ / ° C. or more. Gas leakage was observed, and numerous cracks were observed on the surface of the glass layer (not shown).

  As described above, according to the cylindrical ceramic 62 of the present embodiment, the same effects as those of the first to third embodiments can be obtained.

  Further, according to this embodiment, the porous ceramic substrate 80 of the cylindrical ceramic 62 has a two-layer structure of the inner layer 70 and the dense outer layer 78 having an average pore diameter smaller than that of the inner layer. Since the dense glass layer 18 is formed on the outer surface of the sealing portion 74 of the outer layer 78 of the cylindrical ceramic 62, the surface structure is rougher than that of the cylindrical portion 72 of the outer layer 78. Since the projection 81 having a fractured surface in which the inner layer 70 having a large average pore diameter appears on the surface is covered with the glass layer 18, a good separation film can be formed. Also, the cylindrical ceramic 62 with improved separation performance can be obtained.

  Further, according to the present embodiment, the cylindrical ceramic 62 includes the cylindrical portion 64 and the sealing portion 66 of the inner layer 70 of the porous ceramic base material 80, and the cylindrical portion 72 and the sealing portion 74 of the outer layer 78. The molding base A is supplied into the inner cylinder of the double pipe provided with the inner cylinder and the outer cylinder, and the molding base B is separately supplied and extruded between the inner cylinder and the outer cylinder. Thus, the two-layer structure one-end-sealed cylindrical green molded body that is integrally molded is integrally molded by extrusion molding. The thus configured cylindrical ceramic 62 can be further improved in the separation performance of the separation membrane filter as compared with a single-layered cylindrical ceramic by appropriately adjusting the porosity and average pore diameter of the two-layer structure. it can.

Next, another embodiment of the present invention will be described with reference to FIG. The cylindrical ceramic 10 of this example is formed by the same steps as the manufacturing steps P1 to P7 of the cylindrical ceramic 10 of Example 1 described above, except that the raw materials used and the firing temperature after extrusion are different. In other words, mixing molding aids and water, such as methylcellulose binder was added to mullite particle size 0.5 to 50 [mu] m (average particle diameter _{17μm) (3Al 2 O 3 ·} 2SiO 2), is adjusted by being kneaded 2 was put into an extrusion molding machine 22 and extruded to obtain a single-end sealed cylindrical green molded body similar to the porous ceramic substrate 16 of FIG. This one-end-sealed cylindrical green molded body was dried and then fired at 1550 ° C. for 2 hours, whereby an average pore diameter of 3.2 μm and a porosity of 35% were obtained. A quality ceramic substrate 16 is obtained. In the mixing step P4 to the firing step P7, the glass layer 18 is formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 to constitute the cylindrical ceramic 10 of the present embodiment.

  In order to evaluate the sealing performance of the glass layer 18 formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 of the cylindrical ceramics 10, the glass A to G are processed in the same manner as in Example 1 described above. The cylindrical ceramics 10 in which the sealing part 14 was covered with a glass layer was subjected to a sealing property evaluation test. Further, the linear thermal expansion coefficient of the porous ceramic substrate 16 from 30 ° C. to 500 ° C. was measured by the same method as in Example 1 described above. The linear thermal expansion coefficient of the porous ceramic substrate 16 is shown in FIG. 11, and the results of the sealing evaluation test are shown in FIG.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layers 18 of glass A, C, D, F and G is 2.0 × 10 ⁻⁶ / In the tubular ceramic 10 having a temperature lower than 0 ° C., no gas leak was observed. On the other hand, the cylindrical ceramics 10 whose absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficients of the glass layers of the glass B and E is 2.0 × 10 ⁻⁶ / ° C. or more. Then, a gas leak was observed.

  As described above, according to the cylindrical ceramic 10 of the present embodiment, the same effects as those of the first embodiment can be obtained.

  Next, another embodiment of the present invention will be described with reference to FIG. The cylindrical ceramic 10 of this example is formed by the same steps as the manufacturing steps P1 to P7 of the cylindrical ceramic 10 of Example 1 described above, except that the raw materials used and the firing temperature after extrusion are different. That is, yttria-stabilized zirconia (50 wt%) having an average particle diameter of 1 μm is added to and mixed with yttria-stabilized zirconia (100 wt%) having an average particle diameter of 10 μm, and a molding aid such as a methylcellulose binder and water are added. The formed green body adjusted by mixing and kneading was put into an extruder 22 and extruded to obtain a single-end-sealed cylindrical green molded body similar to the porous ceramic substrate 16 of FIG. This single-end-sealed cylindrical green molded body was dried and then fired at 1550 ° C. for 3 hours to obtain an average pore diameter of 1.2 μm, a porosity of 36%, and a single layer mainly composed of yttria-stabilized zirconia. A porous ceramic substrate 16 having a structure is obtained. In the mixing step P4 to the firing step P7, the glass layer 18 is formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 to constitute the cylindrical ceramic 10 of the present embodiment.

  In order to evaluate the sealing performance of the glass layer 18 formed on the outer surface of the sealing portion 14 of the porous ceramic base material 16 of the cylindrical ceramics 10, the glass A to G are processed in the same manner as in Example 1 described above. The cylindrical ceramics 10 in which the sealing part 14 was covered with a glass layer was subjected to a sealing property evaluation test. Further, the linear thermal expansion coefficient of the porous ceramic substrate 16 from 30 ° C. to 500 ° C. was measured by the same method as in Example 1 described above. The linear thermal expansion coefficient of the porous ceramic substrate 16 is shown in FIG. 11, and the results of the sealing evaluation test are shown in FIG.

In FIG. 13, the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficient of the glass layers 18 of glass A, B, C, D and E is 2.0 × 10 ⁻⁶ / In the tubular ceramic 10 having a temperature lower than 0 ° C., no gas leak was observed. On the other hand, in the case of cylindrical ceramics in which the absolute value of the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 and the linear thermal expansion coefficients of the glass layers of the glass F and G is 2.0 × 10 ⁻⁶ / ° C. or more. Gas leak was observed.

  As described above, according to the cylindrical ceramic 10 of the present embodiment, the same effects as those of the first embodiment can be obtained.

  Next, another embodiment of the present invention will be described. FIG. 27 is a cross-sectional view on a plane passing through the center of the cylindrical ceramics 88 in the width direction. The cylindrical ceramics 88 includes a cylindrical portion 90 and a sealing portion 92 that seals an opening on one side of the cylindrical portion 90, a porous ceramic base material 94 having a single-layer structure of alumina as a main component, and a sealing portion. And a glass layer 18 formed on the outer surface of 92. The sealing portion 92 has a finer pore structure than the cylindrical portion 90.

  The cylindrical ceramic 88 is the same as that of Example 1 described above except that the extrusion molding machine 96 used in the extrusion molding step P2 for molding the porous ceramic substrate 94 and the extrusion molding method using the extrusion molding machine 96 are different. It is formed in the same process as the manufacturing process P1 to P7 of the glass ceramic 10. Therefore, the extrusion process P2 of the porous ceramic substrate 94 having a single layer structure will be described in detail with reference to FIGS.

  FIG. 28 is a cross-sectional view of the extrusion molding machine 96 and the molding substrate C for explaining in detail the molding substrate filling step of the extrusion molding step p2. The extrusion machine 96 includes a base 98 that forms the outer peripheral surface shape of the cylindrical portion 90, a core metal 100 that forms the inner peripheral surface shape of the cylindrical portion 90, and a core metal that forms the inner peripheral surface shape of the sealing portion 92. A tip mold 102 formed of a hemispherical porous body provided at the tip of 100 and a hemispherical recess 104 forming the outer peripheral surface shape of the sealing portion 92 are provided so as to oppose the opening of the base 98. An outer mold 106 made of a porous body and an outer mold holder 108 that detachably accommodates the outer mold 106 from the base 98 are configured. Air holes 110 and 112 are provided in the inside of the core metal 100 and the outer mold holder 108, respectively, and the sealing metal forming space 114 formed by the recess 104 of the tip mold 102 and the outer mold 106 is provided in the core metal 100. Air can be blown through the internal air hole 110 and the air hole 112 of the outer mold holder 108, and air can be sucked from the sealing portion forming space 114. In this extrusion molding machine 96, first, molding is performed toward the sealing portion molding space 114 in a state where air is sucked from the sealing portion molding space 114 indicated by an arrow toward the inside of the core metal 100 and the outside of the outer mold holder 108. The substrate C is filled and extruded. Next, as indicated by an arrow in FIG. 29, air suction from the sealing portion molding space 114 to the inside of the core metal 100 is maintained, and from the outside of the outer mold holder 108 toward the sealing portion molding space 114. The outer mold 106 and the outer mold holder 108 are removed from the base 98 in a state where pressure is applied so that air is blown. Finally, as shown in FIG. 30, pressure is applied so that air is blown from the inside of the core metal 100 through the tip die 102 toward the forming substrate C that forms the sealing portion 92 (in the direction of the arrow), and the desired length is obtained. A porous ceramic substrate 94 having a cylindrical portion 90 is obtained. The porous ceramic base material 94 formed by using the extruder 96 in which the forming base C does not escape in the extruding direction when being extruded in this way is used in the forming base filling step of the extrusion forming step P2. When being pushed out into the sealing portion forming space 114, a high pressure is locally applied with the vicinity of the tip of the sealing portion 92 as the highest, so the tip of the sealing portion 92 is denser than other cylindrical portions 90, for example. It has a hole structure.

  As described above, according to the cylindrical ceramics 88 of the present embodiment, the porous ceramic base 94 is fixed to the opening on one side of the cylindrical portion 90 to seal the opening, and the pore structure with respect to the cylindrical portion 90 is determined. A dense glass layer 18 is formed on the surface of the sealing portion 92 having different portions. For this reason, it becomes possible to form a uniform separation membrane having no defects on the surface of the cylindrical ceramics 88, and to suppress the significant deterioration of the separation performance of the separation membrane filter due to the occurrence of local leakage of the separation membrane. It becomes possible.

  Moreover, according to the cylindrical ceramics 88 of the present embodiment, the same effects as those of the first embodiment can be obtained.

  Next, another embodiment of the present invention will be described. FIG. 31 is a cross-sectional view on a plane passing through the center of the cylindrical ceramic 116 in the width direction. The cylindrical ceramics 88 includes a cylindrical portion 12 and a sealing portion 14 that seals an opening on one side of the cylindrical portion 12, and a porous ceramic base material 16 having a single-layer structure of alumina as a main component, and a sealing portion 14. And a glass layer 18 formed on the surface of the opening opposite to the sealing portion 14. Further, a protrusion 20 having a fracture surface whose surface structure is rougher than that of the cylindrical portion is formed at the tip of the sealing portion 14.

  The cylindrical ceramics 116 is not dipped in the glass slurry constituting the glass layer 18 at the end opposite to the sealing part 14 in addition to the sealing part 14 of the porous ceramic base material 16 in the dipping step P5. These are formed in the same steps as the manufacturing steps P1 to P7 of the cylindrical ceramic 10 of Example 1 described above.

  As described above, according to the cylindrical ceramics 116 of the present embodiment, the same effects as those of the first embodiment can be obtained.

Moreover, according to the cylindrical ceramic 116 of the present embodiment, the glass layer 18 is formed on the surface of the opening on the opposite side of the sealing portion 14 of the porous ceramic substrate 16. In this case, since the glass layer 18 formed on the surface of the opening of the cylindrical ceramic 116 functions as a bonding agent, the sealing member that seals the opening is bonded. When stopping, it is not necessary to apply a tightening force to the opening side end portion, and damage to the cylindrical ceramics 116 due to this can be prevented. Further, since the difference between the linear thermal expansion coefficient of the porous ceramic substrate 16 of the cylindrical ceramic 116 and the linear thermal expansion coefficient of the glass layer 18 is less than 2 × 10 ⁻⁶ / K, At the time of firing in the separation membrane forming step on the surface, it is possible to suitably prevent cracking of the glass layer 18 causing leakage of gas or liquid at the joint between the porous ceramic base material 16 and the sealing member, The separation performance of the separation membrane filter can be further improved.

  Next, another embodiment of the present invention will be described. FIG. 32 is a cross-sectional view on a plane passing through the center of the cylindrical ceramic 118 in the width direction. The cylindrical ceramic 118 is composed of a cylindrical portion 12 and a sealing portion 14 that seals an opening on one side of the cylindrical portion 12, and a porous ceramic base material 16 having a single-layer structure whose main component is alumina, and a sealing portion 14. The glass layer 18 is formed on the outer surface of the cylindrical portion, and the cylindrical ceramic dense body 120 is joined to the end opposite to the sealing portion 14. Further, a protrusion 20 having a fracture surface whose surface structure is rougher than that of the cylindrical portion 12 is formed at the tip of the sealing portion 14.

  In addition to the formation of the glass layer 18 on the outer surface of the sealing portion 14 of the porous ceramic base material 16 in the mixing process P4 to the firing process P7, the cylindrical ceramics 116 seals the porous ceramic base material 16 Except that the ceramic dense body is joined to the end opposite to the portion 14, it is formed by the same steps as the manufacturing steps P1 to P7 of the cylindrical ceramic 10 of Example 1 described above. Therefore, a method for joining the ceramic dense body 120 to the porous ceramic substrate 16 will be described below.

  In the dip process P5, the outer surface of the sealing portion 14 of the porous ceramic base material 16 adjusted in the mixing process P4 is immersed in a glass slurry made of glass frit having the same composition as the glass layer 18, and the glass frit is immersed in the glass frit. After the glass paste prepared by adding and mixing an appropriate binder or solvent is attached (applied) to the annular end surface opposite to the sealing portion 14 of the porous ceramic substrate 16, the cylindrical ceramic dense body 120 is formed. Are combined with the porous ceramic substrate 16 so that the annular end surface thereof comes into contact with the annular end surface of the porous ceramic substrate 16 to which the glass paste is adhered. After the drying process P6, the porous ceramic base material 16 and the ceramic dense body 120 are combined in the firing process P7 and fired at 800 to 950 ° C. for 1 hour, so that the sealing portion 14 of the porous ceramic base material 16 is sealed. Is coated with the glass layer 18 in which the glass frit is melted, and the glass paste adhering to the annular end surface of the porous ceramic base material 16 is melted and fixed, so that the porous ceramic base material 16 is densely ceramic. A cylindrical ceramic 118 in which the body 120 is integrally bonded is obtained.

  As described above, according to the cylindrical ceramics 118 of the present embodiment, the same effects as those of the first embodiment can be obtained.

  Further, according to the cylindrical ceramic 118 of the present embodiment, the ceramic dense body 120 having a cylindrical shape is joined to the end of the porous ceramic base material 16 opposite to the sealing portion 14. In this way, the sealing member can be joined via the ceramic dense body 120 without impairing the strength of the opening of the porous ceramic base material 16, and the tightening force at the time of sealing by the sealing member To the opening-side end portion of the porous ceramic base material 16 becomes unnecessary, and damage to the cylindrical ceramics 118 due to this can be prevented. Thereby, the fall of the separation performance of a separation membrane filter can be suppressed.

  As mentioned above, although this invention was demonstrated in detail with reference to the table | surface and drawing, this invention can be implemented in another aspect, and can be variously changed in the range which does not deviate from the main point.

  For example, the porous ceramic base material 16 of the cylindrical ceramics 10 of Examples 1, 4, and 5 described above was mainly composed of alumina, mullite, and yttria-stabilized zirconia, but is not limited thereto. For example, a porous ceramic substrate may be formed using silica, titania, silicon nitride, or silicon carbide as the main component.

  Further, the above-mentioned cylindrical ceramics 10, 54, 62, 88, 116, 118 are formed on the outer surface of the sealing portion of the porous ceramic base material in which the cylindrical portion and the sealing portion are integrally formed by an extruder. However, the present invention is not limited to this. For example, only the cylindrical portion is formed by extrusion molding, and then the sealing portion is molded manually or sealed by a press molding method. A glass layer 18 is formed on the outer surface of the sealing portion of the porous ceramic base material formed by a method of forming a stopper, a method of bonding a separately prepared sealing portion to one end of the cylindrical portion with a bonding agent, and the like. Even in this case, the separation membrane can be satisfactorily formed, and in addition, the joining strength of the joining portion between the cylindrical portion and the sealing portion can be increased to suppress the occurrence of leakage at the joining portion.

  In addition, the cylindrical portions 12, 64, 72, and 90 described above have a circular cross section, but the cross section may be an ellipse or a polyhedron.

  It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the gist of the present invention. Can do.

10, 54, 62, 88, 116, 118: One-end sealed cylindrical ceramic substrate for separation membrane 12, 64, 72, 90: Cylindrical portion 14, 66, 74, 92: Sealing portion 16, 60, 80 94,: Porous ceramic substrate 18: Glass layer (dense layer)
20, 81: Protrusions 22, 82, 96: Extruder 120: Ceramic dense bodies A, B, C, P: Molding base (ceramic forming raw material)

Claims (9)

One-side-sealed cylindrical ceramic substrate for separation membrane in which a separation membrane is formed on the outer surface,
A cylindrical portion, and a sealing portion that is fixed to an opening on one side of the cylindrical portion to seal the opening, and has a portion having a surface structure or a pore structure different from the cylindrical portion, and the sealing portion A porous ceramic substrate having a fracture surface locally formed on the surface of
A glass layer having a thermal expansion coefficient that is less than 2 × 10 ⁻⁶ / K in terms of a thermal expansion coefficient difference with respect to a thermal expansion coefficient of the porous ceramic base material, and covers the fracture surface on the surface of the sealing portion. A dense layer mainly composed of glass formed directly or indirectly via a porous alumina ceramic layer mainly composed of alumina having an average pore diameter smaller than that of the porous ceramic substrate,
A single-side-sealed cylindrical ceramic substrate for a separation membrane, comprising: The porous ceramic substrate has a multi-layer structure. The single-end sealed cylindrical ceramic substrate for a separation membrane according to claim 1. The separation according to claim 1 or 2, wherein the porous ceramic base material is formed mainly of any one of alumina, zirconia, mullite, silica, titania, silicon nitride, and silicon carbide. One-end sealed cylindrical ceramic substrate for membrane. 4. The difference between the thermal expansion coefficient of the porous ceramic base material and the thermal expansion coefficient of the dense layer containing glass as a main component is less than 1 × 10 ⁻⁶ / K. 5. One end sealing type cylindrical ceramic substrate for a separation membrane according to any one of the above. The composition of the glass contains SiO ₂ as a main component and includes any one of Al ₂ O ₃ , TiO ₂ , ZrO ₂ , ZnO, B ₂ O ₃ , Bi ₂ O ₃ , an alkali metal, and an alkaline earth metal. The single-side sealed cylindrical ceramic substrate for a separation membrane according to any one of claims 1 to 4. After the opening of the die of the extrusion molding machine is closed by the outer mold having a through hole, the cylindrical portion and the sealing portion of the porous ceramic base material are integrally formed by extrusion molding, and then the outer mold The one end-sealed cylindrical ceramics for a separation membrane according to any one of claims 1 to 5, wherein the fracture surface is locally formed on the surface of the sealing portion by removing from the base. A method for producing a substrate. In the state where the opening of the die of the extrusion molding machine is closed by an outer mold having a through hole, the cylindrical portion and the sealing portion of the porous ceramic base material are a multiple tube provided with an inner cylinder and an outer cylinder. Integrated into the inner cylinder and between the inner cylinder and the outer cylinder by extrusion molding to obtain a ceramic multilayer structure integrally formed by separately supplying ceramic molding raw materials having different properties and extruding and joining them. 6. The separation membrane according to claim 1, wherein after the molding, the outer mold is removed from the base, whereby the fracture surface is locally formed on a surface of the sealing portion. For producing a single-end-sealed cylindrical ceramic base material. An opening is formed at the end of the porous ceramic substrate opposite to the sealing portion,
6. A dense layer containing glass as a main component is formed on an end surface of the end portion where the opening is formed, and an inner peripheral surface and an outer peripheral surface adjacent to the end surface. 1. One-end sealed cylindrical ceramic substrate for separation membrane. A single-sided sealing type for a separation membrane according to any one of claims 1 to 5, wherein a cylindrical ceramic dense body is joined to an end of the porous ceramic base opposite to the sealing part. Cylindrical ceramic substrate.