JP2012091097A - Honeycomb structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a honeycomb structure capable of improving the flow of fluid such as exhaust gas and reducing pressure loss.
SOLUTION: A honeycomb-like columnar body 170 having a plurality of flow paths 170a partitioned by partition walls 170c, and a sealing portion 170b that closes one end of the flow path 170a are provided, and among the plurality of flow paths 170a Some of the flow paths are closed at the first end face F1 of the columnar body 170 by the sealing part 170b, and are opened at the second end face F2, and the other flow paths are closed at the second end face F2 by the sealing part 170b. The first end face F1 is open, the sealing portion 170b contains ceramics, the columnar body 170 contains at least one of ceramics and its raw material powder, and at least one of the first end face F1 and the second end face F2. A honeycomb structure having a projecting portion 170d protruding toward the outside of the columnar body 170 on at least a part of the sealing portion 170b on the end face.
[Selection] Figure 2

Description

  The present invention relates to a honeycomb structure and a manufacturing method thereof.

  Conventionally, a honeycomb structure made of porous ceramics has been used as a ceramic filter (DPF: Diesel Particulate Filter) for collecting fine particles such as carbon particles contained in exhaust gas discharged from an internal combustion engine such as a diesel engine. It has been.

  A honeycomb structure for a DPF is usually a columnar body, and the columnar honeycomb structure is formed with a plurality of through holes (flow paths) penetrating between the opposing end faces. On one end surface (first end surface) of the honeycomb structure, the end portions of the open through holes and the end portions of the through holes closed by the sealing portions are alternately arranged in a lattice pattern. The through hole whose end is open on the first end surface is closed with a sealing portion on the second end surface opposite to the first end surface. Further, the through hole whose end is closed by the sealing portion on the first end surface is open on the second end surface. Therefore, in manufacturing a honeycomb structure for DPF, a step of closing only one end portion of the through hole formed in the columnar body with a sealing material (hereinafter referred to as “sealing step”) is required.

  In Patent Document 1 below, as an example of the above-described sealing step, a cordierite columnar body in which a plurality of through-holes are formed is installed in a cylinder, and a part of the through-holes opened on the end surface of the columnar body is formed with a film. A process is disclosed in which a sealing material in the form of a slurry is applied to the end face, and the piston is pushed into the cylinder to introduce the sealing material into some through holes with the piston.

Japanese Patent Publication No. 63-24731

  When the honeycomb structure manufactured by the method including the sealing step disclosed in Patent Document 1 is supplied with exhaust gas from one end face side, the flow of the exhaust gas is disturbed near the end face and pressure loss occurs. There's a problem.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a honeycomb structure that can improve the flow of fluid such as exhaust gas and reduce pressure loss, and a method for manufacturing the honeycomb structure. To do.

  In order to achieve the above object, the present invention includes a honeycomb-shaped columnar body having a plurality of substantially parallel flow paths partitioned by partition walls, and a sealing portion that closes one end of the flow path. A part of the plurality of channels is blocked by the sealing portion at the first end surface of the first end surface and the second end surface of the columnar body substantially orthogonal to the channel, The other end of the flow path is open at the two end faces, and is closed at the second end face by the sealing portion, is open at the first end face, the sealing portion contains ceramics, and the columnar body is ceramics and its Convex portions that include at least one of the raw material powders and project toward the outside of the columnar body on at least a part of the sealing portion in at least one end surface of the first end surface and the second end surface. Having a honeycomb structure To.

  In the conventional honeycomb structure, when a fluid such as exhaust gas is supplied from one end face side, the fluid collides with the sealing portion and the flow is disturbed. On the other hand, according to the honeycomb structure of the present invention, when a fluid such as exhaust gas is supplied from the end surface side having the convex portion by having the convex portion on the sealing portion of one end surface of the columnar body, A fluid flow along the convex portion is formed, the fluid flow becomes smooth, and pressure loss can be reduced.

  The present invention also provides a raw material slurry preparation step for preparing a raw material slurry, and a sealing step in which the raw material slurry is filled in an end portion of a predetermined flow path of the honeycomb formed body and a sealing portion is formed to the vicinity of the end face of the honeycomb formed body. And a projecting portion forming step of forming a projecting portion protruding toward the outside of the honeycomb molded body using the raw material slurry on at least a part of the sealing portion. provide. With this manufacturing method, the above-described honeycomb structure of the present invention can be manufactured.

  In the convex part forming step of the production method of the present invention, it is preferable to form the convex part by flying droplets of the raw material slurry onto the sealing part by an ink jet method. By using the inkjet method, the convex portion can be easily formed. Further, by using the ink jet method, the convex portion can be formed with high accuracy and efficiency.

  ADVANTAGE OF THE INVENTION According to this invention, the honeycomb structure which can improve the flow of fluids, such as waste gas, and can reduce a pressure loss, and its manufacturing method can be provided.

Fig. 1 (a) is a perspective view of a honeycomb structure according to an embodiment of the present invention, and Fig. 1 (b) is an end view of the honeycomb structure of Fig. 1 (a). FIG. 2 is a cross-sectional view taken along line II of the honeycomb structure shown in FIG. Fig. 3 (a) is a perspective view of a honeycomb formed body formed in the manufacturing process of the honeycomb structure according to one embodiment of the present invention, and Fig. 3 (b) is a honeycomb formed body of Fig. 3 (a). FIG. FIG. 4 is a schematic diagram showing a means for supplying the raw material slurry to the inkjet head. FIG. 5 is a partially broken perspective view showing an example (bubble jet (registered trademark) method) of flying the raw slurry as droplets. FIG. 6 is a partially broken perspective view showing another example (piezo method) of the means for flying the raw slurry as droplets. FIG. 7 is a schematic cross-sectional view showing a part of the sealing step in the method for manufacturing a honeycomb structure according to one embodiment of the present invention. Fig.8 (a)-(c) is a schematic cross section which shows a part of sealing process in the manufacturing method of the honeycomb structure which concerns on one Embodiment of this invention. FIG. 9 is a schematic cross-sectional view showing a honeycomb formed body in which a sealing portion is formed by a sealing step of the method for manufacturing a honeycomb structure according to an embodiment of the present invention. FIG. 10 is a schematic cross-sectional view showing a part of the sealing step in the method for manufacturing a honeycomb structure according to one embodiment of the present invention. Fig.11 (a) is a schematic cross section which shows a part of convex part formation process in the manufacturing method of the honeycomb structure which concerns on one Embodiment of this invention, FIG.11 (b) is expansion of the formed convex part. FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same or corresponding parts, and duplicate descriptions are omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

<Honeycomb structure>
Fig. 1 (a) is a perspective view of a honeycomb structure according to an embodiment of the present invention, and Fig. 1 (b) is an end view of the honeycomb structure of Fig. 1 (a). FIG. 2 is a cross-sectional view taken along the line II of the honeycomb structure shown in FIG. As shown in FIGS. 1 and 2, the honeycomb structure 200 includes a honeycomb columnar body 170 having a plurality of substantially parallel flow paths 170a partitioned by partition walls 170c, and one end of the flow path 170a. And a sealing portion 170b for closing. In addition, some of the plurality of channels 170a are blocked by the sealing portion 170b at the first end surface F1 of the first end surface F1 and the second end surface F2 of the columnar body substantially orthogonal to the channel 170a. The second end face F2 opens, and the other flow paths are closed by the sealing portion 170b on the second end face F2, and open on the first end face F1. And the honeycomb structure 200 has the convex part 170d which protruded toward the outer side of the columnar body 170 on the at least one part sealing part 170b in the 1st end surface F1.

  In the honeycomb structure 200 shown in FIGS. 1 and 2, the projecting portion 170 d has a quadrangular pyramid shape whose cross section is a triangle (an isosceles triangle or a regular triangle). In addition, the shape of the convex part 170d is not specifically limited, For example, you may have a shape where a cross section is streamlined shapes, such as a bell shape and a semicircle shape. Moreover, the convex part 170d may be formed so that only a part of surface of the sealing part 170b may be covered. Furthermore, as long as the open flow path 170a is not blocked, it may protrude from the surface of the sealing portion 170b and cover a part of the partition wall 170c. The height H of the convex portion 170d from the first end face F1 of the columnar body 170 is preferably 1 to 3 times the length L of the long side of the sealing portion 170b. When the height H is less than 1 time the length L, the effect of improving the flow of exhaust gas or the like tends to be reduced. When the height H is more than 3 times, the convex portion 170d tends to be broken by a slight stress.

In the honeycomb structure 200, the square size of the cross section of the flow path 170a can be set to 0.5 to 2.5 mm on a side, for example. When the honeycomb structure 200 has a cylindrical shape as shown in FIG. 1, for example, the diameter is preferably about 100 mm or more, the length is about 100 mm or more, and the wall thickness of the partition wall 170c is preferably about 0.5 mm or less. . Further, the cell structure in the honeycomb structure 200 is 100 CPSI or more as the total number of the flow paths 170a, the effective porosity is 30 to 60% by volume, the average pore diameter is 1 to 20 μm, and the pore diameter distribution (D ₉₀ -D ₁₀ ) / D ₅₀ is preferably less than 0.5. Here, D ₁₀ , D ₅₀ , and D ₉₀ are pore diameters when the cumulative pore volume is 10%, 50%, and 90%, respectively, of the total pore volume.

  In the honeycomb structure 200 having the structure shown in FIGS. 1 and 2, the partition walls 170c are made of porous ceramics, and the partition walls serve as a filter. When fluid is supplied to the honeycomb structure 200 from the first end face F1 on the side shown in FIG. 1B (upper end face in FIG. 1A), the fluid flows from the open channel 170a. It enters, passes through the porous partition wall 170c, moves to the flow path 170a where the second end face F2 side is open, and is discharged from the second end face F2. At this time, since the convex portion 170d is formed on the first end face F1 side, the fluid smoothly enters the flow path 170a, and the pressure loss when the fluid passes is reduced.

  The convex portions 170d are not necessarily formed on all the sealing portions 170b in the first end face F1. By forming the convex portion 170d on at least a part of the sealing portion 170b, the effect of improving the fluid flow can be obtained. Actually, as shown in FIG. 1B, in the peripheral edge portion of the first end face F1 of the columnar body 170, the cross-sectional shape of the flow path 170a becomes distorted and the cross-sectional area becomes small. Therefore, the surface area of the sealing portion 170b that closes the flow path 170a is also reduced, and it is difficult to form the convex portion 170d. Therefore, it is preferable not to form the convex portion 170d on the sealing portion 170b at the peripheral edge of the columnar body 170, and to form the convex portion 170d only on the sealing portion 170b having a sufficient surface area.

  Moreover, you may form the convex part 170d not only in the 1st end surface F1 but in the 2nd end surface F2. When the convex portions 170d are formed on both end faces, the effect of improving the flow of the fluid and reducing the pressure loss can be obtained even if the fluid is supplied from any end face side. However, when it is determined that the fluid is supplied only from the first end face F1 side, the convex portion 170d may be formed only on the first end face F1 side.

  In the honeycomb structure 200, the sealing portion 170b includes ceramics, and the columnar body 170 includes at least one of ceramics and raw material powder thereof. Moreover, it is preferable to form the convex part 170d using the same material as the sealing part 170b. The constituent material of the honeycomb structure 200 will be described in detail in the following honeycomb structure manufacturing method.

<Manufacturing method of honeycomb structure>
The method for manufacturing a honeycomb structure of the present invention includes a raw material slurry preparation step for preparing a raw material slurry, filling the raw material slurry into an end portion of a predetermined flow path of the honeycomb formed body, and sealing to the vicinity of the end face of the honeycomb formed body A sealing step for forming a portion, and a convex portion forming step for forming a convex portion protruding toward the outside of the honeycomb formed body using the raw material slurry on at least a part of the sealing portion. It is. Moreover, it is preferable that the manufacturing method of this invention further has a baking process which bakes the honeycomb molded object in which the sealing part and the convex part were formed after a convex part formation process. Hereinafter, each step will be described in detail.

  As the raw material slurry prepared in the raw material slurry preparation step, a mixture of an inorganic compound powder (ceramic material, ceramic raw material powder or a mixture thereof), an organic binder, a lubricant, a pore former, a solvent, and the like may be used. The composition of the inorganic compound powder contained in the raw material slurry may be the same as or different from the composition of the inorganic compound powder for forming the honeycomb formed body described later. Moreover, the organic binder, lubricant, pore-forming agent, solvent and the like contained in the raw slurry can be the same as the material for forming the honeycomb formed body described later.

  The viscosity of the raw material slurry at 23 ° C. is preferably 0.1 to 10 Pa · s and more preferably 1 to 10 Pa · s when the sealing portion is formed by the ink jet method. If this viscosity is less than 0.1 Pa · s, the droplets of the raw material slurry will diffuse after colliding with the partition walls of the honeycomb formed body and tend to be difficult to deposit. It tends to clog, tends to accumulate at the tip of the nozzle, and tends to be difficult to splash.

  In the sealing step, the raw material slurry is filled into the end of a predetermined flow path of the honeycomb formed body, and the sealed portion is formed up to the vicinity of the end face of the honeycomb formed body.

  The honeycomb formed body has a structure as shown in FIG. 3, for example. As shown in FIGS. 3A and 3B, the honeycomb formed body 70 is a cylindrical body having a honeycomb structure. The honeycomb formed body 70 has a plurality of partition walls 70c that are parallel to the central axis and orthogonal to each other. That is, the honeycomb formed body 70 has a lattice structure in a cross section perpendicular to the central axis direction. In other words, the honeycomb formed body 70 is formed with a large number of flow paths 70a (through holes) extending in the same direction (center axis direction), and the partition walls 70c separate the flow paths 70a. Each flow path 70 a is substantially perpendicular to both end faces of the honeycomb formed body 70. The angle formed by the plurality of partition walls 70c included in the honeycomb formed body 70 is not particularly limited, and may be 120 °, for example.

  The honeycomb formed body 70 can be manufactured through, for example, an extrusion forming process in which a raw material mixture is extruded to obtain a honeycomb formed body 70 having a plurality of flow paths 70a (through holes) partitioned by partition walls 70c.

  The raw material mixture for forming the honeycomb formed body is a material that becomes porous ceramics by firing later, and includes a ceramic raw material. The ceramic raw material is not particularly limited, and examples thereof include alumina, silica, mullite, cordierite, glass, oxides such as aluminum titanate, silicon carbide, silicon nitride, and metal. The aluminum titanate can further contain magnesium and / or silicon.

  The raw material mixture preferably contains an inorganic compound source powder that is a ceramic raw material, an organic binder such as methylcellulose, and an additive that is added as necessary.

  For example, when the ceramic is aluminum titanate, the inorganic compound source powder is aluminum source powder such as α alumina powder, titanium source powder such as anatase type or rutile type titania powder, and / or aluminum titanate powder. If necessary, a magnesium source powder such as magnesia powder and magnesia spinel powder and / or a silicon source powder such as silicon oxide powder and glass frit can be further contained.

  Examples of the organic binder include celluloses such as methylcellulose, carboxymethylcellulose, hydroxyalkylmethylcellulose, and sodium carboxymethylcellulose; alcohols such as polyvinyl alcohol; and lignin sulfonate.

  Examples of the additive include a pore-forming agent, a lubricant and a plasticizer, a dispersant, and a solvent.

  Examples of the pore-forming agent include carbon materials such as graphite; resins such as polyethylene, polypropylene, and polymethyl methacrylate; plant materials such as starch, nut shells, walnut shells, and corn; ice; and dry ice.

  Lubricants and plasticizers include alcohols such as glycerin; higher fatty acids such as caprylic acid, lauric acid, palmitic acid, arachidic acid, oleic acid and stearic acid; stearic acid metal salts such as Al stearate; polyoxyalkylene alkyl Examples include ether.

  Examples of the dispersant include inorganic acids such as nitric acid, hydrochloric acid and sulfuric acid; organic acids such as oxalic acid, citric acid, acetic acid, malic acid and lactic acid; alcohols such as methanol, ethanol and propanol; ammonium polycarboxylate Surfactant etc. are mentioned.

  As the solvent, for example, alcohols such as methanol, ethanol, butanol and propanol; glycols such as propylene glycol, polypropylene glycol and ethylene glycol; and water can be used.

  The raw material mixture can be prepared by mixing an inorganic compound source powder, an organic binder, a solvent, and additives that are added as necessary with a kneader or the like.

  The honeycomb formed body 70 can be obtained by extruding the raw material mixture from an extruder having an outlet opening corresponding to the cross-sectional shape of the partition wall 70c, drying it if necessary, and cutting it into a desired length.

  In the sealing step, the method for forming the sealing portion is not particularly limited, but it is preferable to use a method in which the droplets of the raw material slurry are ejected to the portion to be sealed of the honeycomb formed body 70 by the inkjet method to form the sealing portion 70b. For example, an ink jet printer is used as an apparatus for forming the sealing portion by the ink jet method. The printing method of the ink jet printer is a non-contact type in which ink flies in the air. Ink jet printers usually have a mechanism for scanning by the head, and the head has a plurality of nozzles. In the sealing step, droplets of the raw slurry are discharged from a plurality of nozzles provided in the head.

  FIG. 4 is a schematic diagram showing a means for supplying the raw slurry to the nozzles of the ink jet printer. As shown in FIG. 4, the raw material slurry is sucked up by the supply pump 103 from the slurry storage tank 101 through the electromagnetic valve 102, and is supplied to the inkjet head 105 having a plurality of nozzles while adjusting the pressure by the pressure regulating valve 104.

  5 and 6 are partially broken perspective views showing an example of means for flying the raw slurry as droplets. FIG. 5 shows a bubble jet (registered trademark) type (thermal type) inkjet head, and FIG. 6 shows a piezo type. Inkjet heads are respectively shown. In the bubble jet (registered trademark) system shown in FIG. 5, the raw material slurry accommodated in the ink chamber 12 is heated by the heater 16 to generate bubbles (bubbles) 18 in the raw material slurry. In this method, droplets 10 are ejected. On the other hand, in the piezo method shown in FIG. 6, the piezoelectric element 26 is deformed by applying a voltage, thereby transmitting the deformation pressure to the raw material slurry accommodated in the ink chamber 22 and ejecting the raw material slurry droplet 10 from the nozzle 24. It is a method to make it. In the present invention, any method can be suitably used. In the present invention, in addition to the bubble jet (registered trademark) method and the piezo method, a known method such as a heating piezo drive method can be used.

  The scanning direction when scanning the inkjet head may be one-dimensional or two-dimensional. Further, the amount of the droplet 10 ejected from the nozzle is not particularly limited, but is preferably 1 to 20 pL from the viewpoint of easy formation of the sealing portion. Furthermore, although the discharge speed of the droplet 10 discharged from the nozzle is not particularly limited, it is preferably 0.5 to 5 m / s in view of the ease of forming the sealing portion.

  The sealing portion can be formed by the procedure shown in FIGS. That is, as shown in FIG. 7, a method can be used in which the honeycomb formed body 70 is arranged so that the end face is in the horizontal direction, and the droplets 10 of the raw material slurry are ejected in the horizontal direction using the inkjet head 105. Thereby, as shown in FIG. 8A, a sealing layer 70 b 1 is formed in the flow path 70 a to be sealed of the honeycomb formed body 70. The sealing layer 70b1 can be formed by attaching a large number of droplets 10 to the partition walls 70c of the honeycomb formed body 70. Moreover, since formation of the sealing layer 70b1 becomes easy, it is preferable to fly the droplet 10 while drying at a temperature of about 60 to 110 ° C. Subsequently, as shown in FIGS. 8B and 8C, the sealing layer 70b having a desired length can be formed by sequentially laminating the sealing layers 70b2 and 70b3 in the same procedure. Note that the number of the sealing layers stacked is not particularly limited, and the number of stacked layers can be increased until the sealing portion 70b having a required length is obtained. By this method, after forming the sealing portion 70b at a desired position on one end surface (first end surface) of the honeycomb formed body 70, the sealing portion 70b is formed on the first end surface side of the other end surface (second end surface). By forming the sealing portion 70b in the non-flow channel 70a, a honeycomb formed body having the structure shown in FIG. 9 can be obtained. The flow paths 70a in which the sealing portions 70b are formed on the first end surface side and the flow paths 70a in which the sealing portions 70b are formed on the second end surface side are alternately arranged in a grid pattern.

  FIG. 10 shows another method for forming the sealing portion 70b by flying the droplet 10 of the raw slurry. That is, in FIG. 7, the honeycomb formed body 70 is disposed sideways, but as shown in FIG. 10, the honeycomb formed body 70 is disposed such that the end surface is inclined with respect to the horizontal plane, and the inkjet head 105 disposed above the honeycomb formed body 70. Alternatively, a method in which the raw material slurry droplet 10 is blown downward can be used. In this case, it is easy to cause the dropped droplets 10 to adhere to the partition walls 70c of the honeycomb formed body 70. Note that the honeycomb formed body 70 may be disposed such that the end surface is in the horizontal or vertical direction, and the discharge direction of the droplets 10 from the inkjet head 105 may be inclined with respect to the end surface of the honeycomb formed body 70.

  Moreover, in the manufacturing method of this invention, you may perform a sealing process by a conventionally well-known method. For example, the formation of the sealing portion is performed by bringing a mask in which a plurality of through holes are provided at desired positions into close contact with one end surface (first end surface) of the honeycomb molded body 70 and supplying raw material slurry thereto. The sealing portion 70b is formed at the end of the flow path 70a, and the other end surface (second end surface) of the honeycomb formed body 70 is similarly formed on the other end surface where the sealing portion 70b is not formed on the first end surface side. This can be done by forming a sealing part 70b at the end of the flow path 70a. Thereby, a honeycomb formed body having the structure shown in FIG. 9 can be obtained.

  The method for supplying the raw slurry to the flow path 70a is not particularly limited. For example, the raw material slurry supplied onto the mask may be pushed into the flow path through the through-hole of the mask using a squeegee, or may be pushed in by a piston.

  In the convex portion forming step, a convex portion 70d that protrudes toward the outside of the honeycomb formed body 70 is formed on at least a part of the sealing portions 70b using the raw material slurry. The formation method of the convex part 70d is not specifically limited, For example, although the method of forming using a metal mold | die etc. may be used, it is preferable to use the method of forming by the inkjet method. When the ink jet method is used, as in the case where the sealing portion 70b is formed by the ink jet method, droplets of the raw material slurry are ejected onto the sealing portion 70b by the ink jet method to form the convex portion 70d.

  Fig.11 (a) is a schematic cross section which shows the state which formed the convex part 70d on the sealing part 70b with the inkjet method, FIG.11 (b) is an enlarged view of the formed convex part 70d. As shown in FIG. 11B, in the case where the convex portion 70d is formed by the ink jet method, the cross section has a triangular shape by gradually narrowing the portion where the droplet 10 is blown by adjusting the scanning position of the ink jet head 105. A quadrangular pyramid-shaped convex portion 70d can be formed. The convex portion 70d formed in this way may have a stepped cross section as shown in FIG. 11B microscopically. Even when the convex portion 70d is formed by narrowing the scanning range of the inkjet head 105 step by step, the shape of the droplet is usually crushed when the droplet of the raw material slurry reaches the honeycomb formed body 70. The surface of the convex portion 70d becomes smooth.

  In addition, you may perform a convex part formation process after forming the sealing part 70b by the side of a 1st end surface by the sealing process, and before forming the sealing part 70b by the side of a 2nd end surface. In particular, when both the sealing part 70b and the convex part 70d are formed by the ink jet method, it is efficient to continuously form the convex part 70d after forming the sealing part 70b on the first end surface.

  After forming the sealing part 70b and the convex part 70d in the honeycomb molded body 70 by the sealing process and the convex part forming process, a firing process is performed. In the firing step, the honeycomb formed body 70, the sealing portion 70b, and the convex portion 70d are calcined (degreased) and fired, thereby dividing the partition wall 170c made of porous ceramic as shown in FIGS. 1 (a) and 1 (b). A honeycomb structure 200 having a plurality of flow paths 170a partitioned by one end and closed at one end by a sealing portion 170b can be obtained. In the honeycomb structure 200, the flow path 170a closed by the sealing portion 170b on the first end face side is open on the second end face side. The flow path 170a closed by the sealing portion 170b on the second end face side is open on the first end face side. A convex portion 170d is formed on at least a part of the sealing portion 170b on the first end surface side. As described above, when the sealing step and the convex portion forming step are performed on the green molded body (unfired molded body) before firing, and then the firing step is performed, the firing process may be performed once and after firing. This is preferable because good adhesion between the sealing portion 170b and the honeycomb structure can be obtained.

  The calcination (degreasing) is a step for removing the organic binder in the honeycomb formed body 70, the sealing portion 70b and the convex portion 70d and the organic additive blended as necessary by burning, decomposition, etc. Typically, the temperature is raised to a firing temperature (for example, a temperature range of 150 to 900 ° C.). In the calcination (degreasing) step, it is preferable to suppress the temperature increase rate as much as possible.

  The firing temperature in firing the honeycomb formed body 70 is usually 1300 ° C. or higher, preferably 1400 ° C. or higher. The firing temperature is usually 1650 ° C. or lower, preferably 1550 ° C. or lower. The rate of temperature increase up to the firing temperature is not particularly limited, but is usually 1 ° C./hour to 500 ° C./hour.

  Firing is usually carried out in the atmosphere, but depending on the type of raw material powder used and the amount used, it may be fired in an inert gas such as nitrogen gas or argon gas, carbon monoxide gas, hydrogen gas, etc. You may bake in reducing gas like this. Further, the firing may be performed in an atmosphere in which the water vapor partial pressure is lowered.

  Firing is usually performed using a conventional firing furnace such as a tubular electric furnace, a box-type electric furnace, a tunnel furnace, a far-infrared furnace, a microwave heating furnace, a shaft furnace, a reflection furnace, a rotary furnace, or a roller hearth furnace. Firing may be performed batchwise or continuously. Moreover, you may carry out by a stationary type and may carry out by a fluid type.

  The time required for firing is sufficient as long as it is sufficient for ceramics to be formed, and it varies depending on the amount of the honeycomb formed body, the type of firing furnace, firing temperature, firing atmosphere, etc., but is usually 10 minutes to 24 hours. .

  In addition, you may perform a baking process before a sealing process. However, in that case, it is necessary to perform a baking process again after a sealing process and a convex part formation process.

  Through the above steps, the target honeycomb structure 200 can be obtained. The obtained honeycomb structure 200 can be processed into a desired shape by grinding or the like.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation aspect is possible. For example, the shape of the honeycomb structure of the present invention is not particularly limited, and can take any shape depending on the application. For example, the outer shape is not limited to a cylinder. For example, a regular polygonal column such as a regular triangular prism, a square column, a regular hexagonal column, or a regular octagonal column, or a column other than a regular polygonal column, such as a triangular column, a quadrangular column, a hexagonal column, or an octagonal column. It can be a body. Also, the cross-sectional shape of each flow path is not limited to a square, and can be rectangular, circular, elliptical, triangular, hexagonal, octagonal, etc. Different shapes may be mixed. Furthermore, the arrangement of the channels is not limited to a square arrangement, and may be an equilateral triangle arrangement in which the center of the channel is arranged at the apex of an equilateral triangle in a cross section, a staggered arrangement, or the like.

  The honeycomb structure of the present invention includes, for example, an exhaust gas filter used for exhaust gas purification of an internal combustion engine such as a diesel engine and a gasoline engine, a filter used for filtering food and drink such as a catalyst carrier and beer, and a gas generated during petroleum refining. The present invention can be suitably applied to ceramic filters such as a selective transmission filter for selectively transmitting components such as carbon monoxide, carbon dioxide, nitrogen and oxygen.

DESCRIPTION OF SYMBOLS 10 ... Droplet, 70 ... Honeycomb molded object, 70a ... Channel, 70b ... Sealing part, 70c ... Partition, 105 ... Inkjet head, 170 ... Columnar body, 170a ... Channel, 170b ... Sealing part, 170c ... Partition, 170d ... convex part, 200 ... honeycomb structure.

Claims (3)

A honeycomb-shaped columnar body having a plurality of substantially parallel flow paths partitioned by partition walls;
A sealing portion for closing one end of the flow path;
With
Some of the plurality of channels are blocked by the sealing portion at the first end surface of the first end surface and the second end surface of the columnar body substantially orthogonal to the channel, and Open at the end face,
The other channel is blocked by the sealing portion at the second end surface, and is open at the first end surface,
The sealing portion includes ceramics;
The columnar body includes at least one of ceramics and raw material powder thereof,
A honeycomb structure having a convex portion protruding toward the outside of the columnar body on at least a part of the sealing portion on at least one of the first end surface and the second end surface. A raw material slurry preparation step of preparing a raw material slurry;
A sealing step of filling the raw material slurry into an end portion of a predetermined flow path of the honeycomb formed body and forming a sealing portion up to the vicinity of the end face of the honeycomb formed body;
A projecting portion forming step of forming a projecting portion protruding toward the outside of the honeycomb formed body using the raw material slurry on at least a part of the sealing portion;
The manufacturing method of the honeycomb structure which has this. The method for manufacturing a honeycomb structure according to claim 2, wherein, in the convex portion forming step, the convex portions are formed by flying droplets of the raw material slurry onto the sealing portion by an ink jet method.

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