JP2010126379A - Honeycomb structural body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a honeycomb structural body in which a honeycomb body and a joining layer are firmly joined and stably usable. <P>SOLUTION: The honeycomb structural body 1 has a nearly pillar-shaped honeycomb body 2 in which a large number of cells which are made of porous ceramics and extend in the axial direction are partitioned and a joining layer 5 which is made of a ceramic joined to the outer periphery of the honeycomb body 2. On the outer periphery of the honeycomb body 2, recesses 6 which are recessed from the outer periphery are formed, and the joining layer 5 is characterized by joining ceramics also at the inner surfaces of the recesses 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a honeycomb structure, and more particularly to a honeycomb structure including a honeycomb body and a bonding layer formed on the outer periphery of the honeycomb body.

  Catalytic carrier utilizing catalytic action of internal combustion engine, boiler, chemical reaction equipment, fuel cell reformer, etc., particulates such as soot in exhaust gas (particularly particulate matter (PM) in exhaust gas from diesel engine) A ceramic honeycomb structure is used for a collection filter (hereinafter referred to as DPF).

  A honeycomb structure made of ceramic is generally made of porous ceramics, and partition walls that divide a plurality of cells serving as fluid flow paths by partition walls, and adjacent cells are opposite to each other so that the end faces are in a checkered pattern. And a sealing portion made of ceramics that seals the end portion on the side.

  A DPF made of a ceramic honeycomb structure is used as a wall flow type catalyst in which exhaust gas passes through partition walls that partition partition wall cells. The wall flow type catalyst collects PM in the exhaust gas through which the exhaust gas passes through the continuous pores formed in the cell wall and cannot pass through the pores.

  Since the DPF is clogged when the collected PM is accumulated, it is necessary to remove the collected PM. One method of removing the collected PM is a method of decomposing and removing PM by combustion or the like. There is also a method in which DPF supports a catalytic metal that exhibits catalytic activity and decomposes PM with this catalytic metal.

  When removing PM by combustion, the honeycomb structure rises due to combustion heat. In particular, when combustion of the collected PM continues in a chain, the temperature of the honeycomb structure excessively increases in a short time. When such a rapid temperature change occurs, thermal expansion and contraction occur, and the occurrence of cracks due to stress accompanying this volume change has been a problem.

  In order to alleviate this thermal stress, a honeycomb structure having a so-called divided structure has been developed, which has a plurality of parts of a honeycomb structure and a bonding material layer for bonding the honeycomb structure. A honeycomb structure having such a structure is described in Patent Document 1, for example.

However, the honeycomb structure having a divided structure has a problem that separation occurs between the honeycomb body and the bonding material layer due to repeated volume changes during use. If separation occurs between the honeycomb segment and the bonding material layer, the honeycomb segment may fall out of the honeycomb structure, or exhaust gas may pass through gaps generated by the separation, which may reduce exhaust gas purification performance. there were.
Japanese Patent No. 3893049

  The present invention has been made in view of the above circumstances, and in a honeycomb structure having a bonding layer bonded to a honeycomb body, the honeycomb body and the bonding layer are firmly bonded and can be used stably. An object is to provide a honeycomb structure.

  In order to solve the above-mentioned problems, the present inventors have studied the shape of the bonding interface between the honeycomb body and the bonding layer, and as a result, have come to make the present invention.

  That is, the honeycomb structure of the present invention includes a substantially columnar honeycomb body made of porous ceramics and having a plurality of cells extending in the axial direction, and a joining layer made of ceramics joined to the outer periphery of the honeycomb body. The honeycomb structure is characterized in that a concave portion recessed from the outer peripheral surface is formed on the outer peripheral surface of the honeycomb body, and the bonding layer has ceramics bonded to the inner surface of the concave portion.

  In the honeycomb structure of the present invention, a recess is formed on the outer peripheral surface of the honeycomb body, and ceramics are also bonded to the inner surface of the recess. By bonding the bonding layer also on the inner surface of the recess, the area of the bonding interface between the honeycomb body and the bonding layer is increased, and the bonding property between the two is enhanced. Further, the improved bondability between the honeycomb body and the bonding layer prevents the honeycomb body from falling off and the purification performance from being lowered due to peeling at the interface between the two.

  The honeycomb structure of the present invention is made of porous ceramics, and has a honeycomb body having a plurality of cells extending in the axial direction, and a bonding layer made of ceramics bonded to the outer periphery of the honeycomb body.

  In the ceramic honeycomb structure of the present invention, the honeycomb body is formed with a recess recessed from the outer peripheral surface, and the bonding layer is bonded to the ceramic also on the inner surface of the recess. That is, a recess is formed on the outer peripheral surface of the honeycomb body. The formation of the recesses increases the surface area of the outer periphery of the honeycomb body. And the joining layer joined to the outer periphery of a honeycomb body joins also the inner surface of a recessed part, and both joining area becomes large. When the bonding area between the honeycomb body and the bonding layer increases, the bonding strength between the two increases. As a result, peeling of both can be suppressed. Moreover, in the honeycomb structure of the present invention, ceramics that form a bonding layer also enter the inside of the recesses on the outer peripheral surface of the honeycomb body, so that the bonding strength between the two is further improved by the anchor effect.

  In the ceramic honeycomb structure of the present invention, the shape (cross-sectional shape) of the recess on the outer periphery of the honeycomb body is not particularly limited, but the depth of the recess is preferably 1.0 mm or less. The depth of the recess recessed from the outer peripheral surface of the honeycomb body is the distance from the opening of the recess to the deepest portion of the recess.

  If the depth of the concave portion exceeds 1.0 mm, the depth of the concave portion becomes too deep, which hinders the bonding of the honeycomb body with the bonding layer, or the bonding layer becomes thicker than necessary. In addition, handling may be difficult due to the weakness of the protruding portion (the protruding portion from the bottom surface of the recess) defining the recess. A more preferable depth of the recess is 0.01 to 0.5 mm.

  In the ceramic honeycomb structure of the present invention, the shape of the recesses on the outer peripheral surface of the honeycomb body may be any shape that does not affect the bondability between the honeycomb body and the bonding layer. For example, along the axial direction of the honeycomb body In addition, one or more grooves or indentations formed periodically or aperiodically can be used. Further, the concave portion may be a portion other than the protruding portion formed periodically or aperiodically on the outer peripheral surface of the honeycomb body.

  In the ceramic honeycomb structure of the present invention, the shape of the concave portion on the outer peripheral surface of the honeycomb body is preferably one or more grooves along the axial direction of the honeycomb body. In the case where extrusion molding is used when forming a honeycomb body, the groove along the axial direction is formed with a shape that becomes a recess in the mold, and the pressure during molding and the hardness of the raw material are adjusted. The groove can be easily formed by such a method.

  When the recess is one or more grooves extending along the axial direction of the honeycomb body, the cross-sectional shape thereof is not particularly limited. For example, the side wall surface defining the recess is perpendicular to the bottom surface. Examples of the shape include a concave shape, a shape in which the opening width is narrower than the width of the bottom surface portion (substantially trapezoidal cross section), and a substantially U shape in which the bottom surface defining the concave portion is curved.

  In the present invention, the bonding layer is not limited as long as it is a member made of ceramic bonded to the outer peripheral surface of the honeycomb body.

  The honeycomb body is preferably a plurality of honeycomb segments, and the bonding layer is preferably a bonding material layer for bonding the plurality of honeycomb segments. A honeycomb structure formed by bonding a plurality of honeycomb segments with a bonding material layer has a limited volume change of each honeycomb segment when a volume change due to heat occurs. Will not occur. In addition, the joint surfaces of the honeycomb bodies can be planar, and the recesses can be easily formed.

  The bonding layer is preferably a peripheral material layer formed on the outer periphery of the honeycomb body. By having the outer peripheral material layer, the shape change that occurs when the honeycomb structure is used for a DPF or the like can be suppressed. Specifically, when the honeycomb structure is used for applications such as DPF, the honeycomb structure is exposed to high heat. The honeycomb structure undergoes thermal expansion. This thermal expansion can be suppressed by having the outer peripheral material layer. A conventionally known material can be used as the material constituting the outer peripheral material layer. For example, SiC, silica compounds, alumina compounds such as aluminum titanate, and the like can be used.

  In the honeycomb structure of the present invention, the ceramic used in the conventionally known honeycomb structure can be used as the porous ceramic forming the honeycomb structure. As the ceramic, it is preferable that a main component is one selected from aluminum titanate, silicon carbide, silicon nitride, and cordierite. In particular, from the viewpoint of heat resistance and thermal shock resistance, the honeycomb body is more preferably composed mainly of silicon carbide (SiC). Any porous ceramics may be used as long as it is composed of SiC as a main component, and the present invention is not limited to the one made only of SiC. Moreover, the pore diameter (average pore diameter) and porosity of SiC ceramics are not particularly limited.

  In the honeycomb structure of the present invention, it is preferable that the SiC ceramics include ceramic powder made of SiC and a binder made of SiC that bonds SiC particles constituting the ceramic powder. This SiC ceramic has a configuration in which adjacent SiC particles are fixed with a binder. With such a configuration, the degree of freedom in pore design in the porous ceramic is improved. That is, the size and distribution of the gaps between the ceramic particles that become the pores can be easily controlled. And the porous ceramics which have this pore in a uniform state can be obtained.

  This SiC ceramic is obtained by bonding SiC powder (particles) with a SiC binder. That is, the particles and the binder are made of the same material, and peeling at the interface between the SiC particles and the binder is less likely to occur, and the bondability is improved. That is, the strength of the porous ceramic itself constituting the honeycomb body is improved and the thermal shock resistance is excellent.

  Furthermore, this SiC ceramic has a large number of fine pores, and these pores buffer the volume change at the time of thermal expansion (shrinkage) of the honeycomb structure. Thereby, the volume change of ceramic particles can be buffered further.

This SiC ceramic can be formed by performing a heat treatment in a state where SiC powder, Si ₃ N ₄ powder, and C powder are mixed. The Si ₃ N ₄ powder Si ₃ N ₄ and the C powder C react with each other by heat of heat treatment to generate SiC as a binder.

  The heat treatment temperature of the mixed powder of each powder is not limited, but is preferably lower than the temperature at which SiC is sintered (2300 ° C.), and more preferably 2000 ° C. or higher. The lower the heat treatment temperature, the more the SiC production reaction does not proceed, and the higher the heat treatment temperature, the easier the sintering of the SiC powder.

  When the honeycomb body is composed of the honeycomb body and the bonding material layer, the material is not limited as in the above honeycomb body, but it is preferable that SiC be a main component. The bonding material layer can also be formed using, for example, a SiC-based bonding material. The bonding material layer formed between the honeycomb bodies when the honeycomb bodies are bonded with the bonding material is preferably formed with a thickness of 0.5 to 5 mm.

  In the honeycomb structure of the present invention, it is preferable that one end or the other end of a large number of cells is sealed with a sealing material made of ceramics. A wall flow type honeycomb structure can be formed by sealing one end or the other end of the cell with a sealing material. The material of the ceramic constituting the sealing material is not particularly limited, and may be the same as or different from the porous ceramic constituting the honeycomb structure. More preferably, the ceramic is mainly composed of porous ceramics constituting the honeycomb body.

  The honeycomb structure of the present invention is preferably used for a DPF. The honeycomb structure of the present invention can be used as a wall flow type filter catalyst in which exhaust gas (gas) passes through partition walls that partition cells, and among these filter catalysts, it is particularly preferable to use as a DPF.

  When the honeycomb structure of the present invention is used as a DPF, it is preferable to support at least one of a porous oxide made of alumina or the like and a catalyst metal such as Pt, Pd, or Rh on at least the pore surfaces of the partition walls. By carrying these substances, purification performance such as particulates as DPF is improved.

  The outer peripheral shape of the honeycomb structure of the present invention is not particularly limited, and can be a conventionally known shape. For example, the cross section can be a substantially cylindrical shape having a perfect circle or an ellipse, and the square shape having a square or polygonal cross section.

  Although the manufacturing method of the honeycomb structure of the present invention is not particularly limited, for example, it can be manufactured by the following manufacturing method.

  First, a clay-like raw material mixture capable of forming a honeycomb body after heat treatment (or firing) is formed into a substantially prismatic honeycomb body shape with cells partitioned in the axial direction by extrusion. At this time, irregularities that substantially match the cross-sectional shape of the concave portions are formed in the portion of the mold corresponding to the outer peripheral surface of the honeycomb body, and concave portions including a plurality of grooves are formed on the outer peripheral surface of the extruded molded body. Is done. Thereafter, heat treatment is performed at a temperature lower than the firing temperature. Then, clay (slurry) capable of forming ceramics mainly composed of ceramics constituting the honeycomb body when fired is prepared, and this clay is injected into the end of the cell of the bonded body of the honeycomb body. It is preferable that the clay is injected such that each end face has a checkered pattern. At this time, it is preferable that clay is injected into both ends of the cells that define the outer peripheral surface of the honeycomb structure.

  The formed body into which the clay has been injected is heated and fired to produce a honeycomb body in which a sealing portion of 0.5 mm or more is formed at the end of the cell.

  Thereafter, a conventionally known bonding material (for example, SiC-based bonding material) is applied to the outer peripheral surface of the formed body, and another honeycomb segment is bonded to the coated surface, followed by heating and firing.

  Subsequently, the outer peripheral surface in the circumferential direction of the fired body is formed by means such as cutting. In this molding, it is preferable that the cells having the sealing portions at both ends form the outer peripheral surface.

  And the outer periphery material slurry which has SiC as a main component is apply | coated to the outer peripheral surface of the circumferential direction, a drying and heat processing are performed, and an outer periphery material layer is formed. In this way, the honeycomb structure of the present invention can be manufactured.

  Hereinafter, the present invention will be described using examples.

  As an example of the present invention, a honeycomb structure for DPF was manufactured.

Example 1
A method for manufacturing the DPF honeycomb structure of the present example will be described below.

First, 75 parts by weight of SiC powder having an average particle diameter of 12 μm, 20 parts by weight of Si ₃ N ₄ powder having an average particle diameter of 10 μm, and 5 parts by weight of C powder having an average particle diameter of 15 μm were weighed, and methyl cellulose was added as an organic binder. A surfactant was added to what was made moderate viscosity by adding water and mixed and kneaded. The obtained clay was molded by an extrusion method using a mold having an opening of a predetermined shape and dried. In this mold, as shown in FIG. 1, irregularities are formed on the mold surface corresponding to the outer peripheral surface of the honeycomb body. This molded body has a prismatic shape with a square cross section, and has cells with a square cross section. Moreover, this molded object is formed with a plurality of grooves having a concave cross section corresponding to the mold on the outer peripheral surface.

  After drying, the clay used for the production of the molded body was poured into predetermined cells from both ends of the dried molded body and dried at 80 ° C. Here, the predetermined cell is formed so that the cell into which the clay is injected has a checkered pattern. Also, clay was injected only into one end or the other end of the cell.

  Thereafter, the molded body in which the slurry was injected into the cell was heat-treated at 2100 ° C., and the molded body was fired. Thereby, the honeycomb segment 2 was manufactured.

  The manufactured honeycomb body 2 has a square shape with a cross section perpendicular to the axial direction having a side of 36 mm and an axial length (L) of 152 mm. Then, as shown in FIG. 2, a groove 60 having a concave cross section with a width of the opening is the width of the opening of the cell and a depth of about 0.05 mm is formed on the outer peripheral surface. Yes. That is, a recess 6 having a depth of about 0.05 mm is formed. Here, the protruding portion that partitions the side wall surface of the groove 60 has a shape in which the cell wall that partitions the cells of the honeycomb segment 2 is extended.

  Further, the manufactured honeycomb body 2 is encapsulated with the sealing material 3 so that the end face has a checkered pattern.

  Then, the honeycomb bodies 2 were bonded together with a SiC bonding material. This SiC-based bonding material is composed of 35 parts by weight of SiC powder (coarse powder) having an average particle diameter (D50) of 38 μm (trade name: GP # 400, manufactured by Shinano Denki Smelting Co., Ltd.) and SiC powder having D50 of 1.0 μm. (Fine powder) (Shinano Denki Smelting Co., Ltd., trade name: SER-A10) 29 parts by weight, inorganic fiber made of mullite with a fiber length of 1 mm or less (Shin Nikka Thermal Ceramics Co., Ltd., trade name: SC1260-) A10) 10 parts by weight, an organic binder made of an aqueous solution containing 1.5% by weight of carboxymethyl cellulose (CMC) (manufactured by Daicel Chemical Industries, Ltd., trade name: DN400H), 10 parts by weight of an inorganic binder made of colloidal silica (Nissan Chemical Industries) 16 parts by weight manufactured by Co., Ltd. and trade name: Snowtex O) were weighed and kneaded.

  In the bonding with the bonding material, the bonding material is applied to the outer peripheral surface of the honeycomb divided body 2 where the recesses 6 are formed so that the thickness becomes 1.0 ± 0.5 mm, and then another honeycomb divided body 2 is attached to this surface. And joined together. This joining was repeated, and 16 honeycomb bodies 2 were joined so that the cross section was a square, and dried at 80 ° C. The end face of the joined body of the honeycomb segment 2 is shown in FIG.

  Then, this joined body was cut using an electric saw to form an outer peripheral shape. The cutting with the electric saw was made so that the cell in which the sealing material was formed at both ends formed a substantially cylindrical shape forming the outer peripheral surface.

  Subsequently, a peripheral material slurry was prepared. The outer peripheral material slurry was composed of 50 parts by weight of SiC powder having an average particle diameter of 20 μm, 19 parts by weight of spherical silica powder having an average particle diameter of 1 μm, 25 parts by weight of a 1.26 wt% CMC solution as a binder, and an anionic dispersant 1 as a dispersant. It was prepared by thoroughly mixing parts by weight and 5 parts by weight of colloidal shear force as a binder.

  And the outer periphery material slurry prepared to the sintered body after grinding was apply | coated to the outer peripheral surface of the cutting body, and it dried at 80 degreeC, Then, it heated at 850 degreeC and solidified the joining material and slurry. Thereby, the outer peripheral material layer 4 having a thickness of 0.5 mm was formed on the outer peripheral surface.

  As described above, the honeycomb structure 1 of this example could be manufactured. The honeycomb structure 1 of this example is shown in FIG. 4 at its end face.

  In the honeycomb structure 1 of the present embodiment, a plurality of substantially pillar-shaped honeycomb segments 2 having a square cross section are bonded via a bonding material layer 5, and an outer circumferential material layer 4 is formed on the outer periphery in the circumferential direction. And the recessed part 6 which consists of the groove 60 extended along an axial direction is formed in the outer peripheral surface of the honeycomb segment 2, and the joining material layer 5 penetrates into the inside of the recessed part 6, and is formed.

(Example 2)
This example is a honeycomb structure manufactured in the same manner as Example 1 except that the shape (depth) of the recess 6 on the outer peripheral surface of the honeycomb divided body 2 is different.

  In the honeycomb segment used in this example, a groove having a concave cross section with a width of the opening equal to the width of the opening of the cell and a depth of 2 mm is formed. That is, a recess 6 having a depth of 2 mm is formed.

(Example 3)
This example is a honeycomb structure manufactured in the same manner as Example 1 except that the shape (depth) of the recess 6 on the outer peripheral surface of the honeycomb divided body 2 is different.

  In the honeycomb segment used in this example, the width of the opening is the width of the opening of the cell, and grooves having a concave cross section with a depth of 3 mm are formed. That is, a recess 6 having a depth of 3 mm is formed.

(Comparative Example 1)
This comparative example is a honeycomb structure manufactured in the same manner as in Example 1 except that the shape of the outer peripheral surface of the honeycomb divided body 2 is different.

  The honeycomb segment used in this comparative example is formed so that the outer peripheral surface is a smooth surface.

(Evaluation)
The honeycomb structures of the examples and comparative examples were evaluated.

(An endurance test)
First, the honeycomb structures of the examples and comparative examples were set as DPFs in an actual vehicle exhaust system, and the state of the honeycomb structures after PM collection and combustion were observed.

  Specifically, a honeycomb structure was assembled in an exhaust system of a vehicle equipped with a QD32 diesel engine (Nissan Motor), and the engine was driven to collect soot (PM). When the amount of PM collected was 8 g, PM was burned in the state of the engine bench. The state of the honeycomb structure after PM combustion was observed.

  The honeycomb structures of Examples 1 to 3 were not damaged even after PM was burned. In addition, the honeycomb structures of Examples 1 and 2 could be easily applied without causing damage to the unevenness defining the recesses 6 on the outer peripheral surface of the honeycomb divided body 2 when the bonding agent was applied. In the honeycomb structure of Comparative Example 1, cracking and peeling were confirmed at a part of the bonding interface between the honeycomb body 2 and the bonding material layer 5.

  As described above, the honeycomb structures of the respective examples in which the concave portions 6 are formed on the outer peripheral surface of the honeycomb body 2 are not damaged at the interface between the honeycomb body and the bonding material layer, and can be used stably. This is a honeycomb structure that can be used.

Example 4
This example is a honeycomb structure manufactured in the same manner as in Example 1 except that the cross-sectional shape of the recess 6 on the outer peripheral surface of the honeycomb divided body 2 is different.

  In the honeycomb segment used in this example, as shown in FIG. 5, grooves having an opening width of 2 mm, a bottom width of 2.2 mm, and a depth of 2 mm are formed. That is, the groove 60 having a substantially trapezoidal cross section whose bottom surface is wider than the opening is formed.

(Example 5)
This example is a honeycomb structure manufactured in the same manner as in Example 1 except that the method for forming irregularities on the outer peripheral surface of the honeycomb divided body 2 is different.

  A method for manufacturing the honeycomb structure of the present example will be described below.

First, in the same manner as in Example 1, 75 parts by weight of SiC powder having an average particle diameter of 12 μm, 20 parts by weight of Si ₃ N ₄ powder having an average particle diameter of 10 μm, and 5 parts by weight of C powder having an average particle diameter of 15 μm were weighed. Extrusion of clay obtained by adding water to methyl cellulose and adding a surfactant to a moderate viscosity and mixing and kneading the resulting clay with a mold with a predetermined opening Molded by the method and dried. This mold has no irregularities on the mold surface corresponding to the outer peripheral surface of the honeycomb segment 2. This molded body has a prismatic shape with a square cross section, and has cells with a square cross section. Moreover, the outer peripheral surface of this molded object is formed smoothly. Then, the shaping | molding die provided with the unevenness | corrugation which can form a groove | channel on the surface was pressed on the outer peripheral surface of this molded object.

  After drying, the clay used for the production of the molded body was poured into predetermined cells from both ends of the dried molded body and dried at 80 ° C. Here, the predetermined cell is formed so that the cell into which the clay is injected has a checkered pattern. Also, clay was injected only into one end or the other end of the cell.

  Thereafter, the molded body in which the slurry was injected into the cell was heat-treated at 2100 ° C., and the molded body was fired. Thereby, the honeycomb segment 2 of the present example was manufactured.

  Thereafter, in the same manner as in Example 1, the honeycomb structure of the present example was manufactured.

  The present embodiment is a honeycomb structure similar to that of the first embodiment except that the manufacturing method is different, and exhibits the same effects as those of the first embodiment.

(Modification of Example 5)
The molding die for forming the recess 6 on the outer peripheral surface of the clay molded body may have a cylindrical roller shape in which irregularities are formed along the circumferential direction. This mold can continuously form the recess 6 on the outer peripheral surface of the molded body.

(Example 6)
This example is a honeycomb structure manufactured in the same manner as Example 5 except that the shape (opening shape) of the recess 6 on the outer peripheral surface of the honeycomb body 2 is different.

  In the honeycomb segment 2 used in this example, as shown in FIG. 6, grooves 60 and 61 having an opening width of 2 mm and a depth of 2 mm have meshes in which intersecting grooves are orthogonal to each other. It is formed in a shape. That is, a recess 6 having a difference of 2 mm between the highest part and the lowest part is formed.

  In the honeycomb body 2 of the present embodiment, grooves 60 and 61 extending in the axial direction and in the direction orthogonal to the axial direction are formed. That is, even if peeling occurs at the interface with the bonding material layer 5 bonded to the inner surface of the groove 60 for some reason, the progress of peeling is suppressed by the groove 61 orthogonal to the groove.

(Example 7)
This example is a honeycomb structure manufactured in the same manner as in Example 5 except that the shape (opening shape) of the unevenness on the outer peripheral surface of the honeycomb divided body 2 is different.

  In the honeycomb segment 2 used in this example, as shown in FIG. 7, the recesses 62 having a square opening and a depth of 2 mm are periodically formed. That is, a recess 6 is formed that is formed by a recess 62 having a depth of 2 mm.

  Also in the honeycomb segment 2 of the present example, the width of the unevenness is different in the portion where the position in the axial direction is different. As a result, the same effect as in Example 6 can be exhibited.

(Example 8)
A method for manufacturing the honeycomb structure of the present example will be described below.

First, in the same manner as in Example 1, 75 parts by weight of SiC powder having an average particle diameter of 12 μm, 20 parts by weight of Si ₃ N ₄ powder having an average particle diameter of 10 μm, and 5 parts by weight of C powder having an average particle diameter of 15 μm were weighed. As described above, a surfactant was added to a mixture obtained by adding water to methyl cellulose to obtain an appropriate viscosity, and then mixed and kneaded. The obtained clay was molded by an extrusion method using a mold having an opening of a predetermined shape and dried. In this mold, irregularities are formed on the mold surface corresponding to the outer peripheral surface of the honeycomb body. This molded body has a cylindrical shape in which the outer peripheral shape of the cross section perpendicular to the axial direction is a substantially circular cylinder, and the cross section is divided into squares. Further, in this molded body, a plurality of concave grooves corresponding to the molding die are formed on a cylindrical outer peripheral surface.

  After drying, the clay used for the production of the molded body was poured into predetermined cells from both ends of the dried molded body and dried at 80 ° C. Here, the predetermined cell is formed so that the cell into which the clay is injected has a checkered pattern. Also, clay was injected only into one end or the other end of the cell.

  Thereafter, the molded body in which the slurry was injected into the cell was heat-treated at 2100 ° C. to fire the molded body. Thereby, the honeycomb body 7 was able to be manufactured.

  The manufactured honeycomb body 7 has a circular shape with an outer peripheral diameter of 144 mm, and is formed in a substantially cylindrical shape with an axial length (L) of 152 mm. And as shown in FIG. 8, the width | variety of the opening part is the width | variety of the opening part of a cell, and the depth of 0.1-0.2 mm is formed in the outer peripheral surface. That is, the unevenness | corrugation whose difference between the highest part and the lowest part is 0.1-0.2 mm is formed.

  Further, as shown in FIG. 8, the manufactured honeycomb body 7 is sealed with the sealing material 3 so that the end face has a checkered pattern.

  Subsequently, a peripheral material slurry was prepared. The outer peripheral material slurry was composed of 50 parts by weight of SiC powder having an average particle diameter of 20 μm, 19 parts by weight of spherical silica powder having an average particle diameter of 1 μm, 25 parts by weight of a 1.26 wt% CMC solution as a binder, and an anionic dispersant 1 as a dispersant. It was prepared by thoroughly mixing parts by weight and 5 parts by weight of colloidal shear force as a binder.

  The prepared outer peripheral material slurry was applied to the outer peripheral surface of the honeycomb body, dried at 80 ° C., and then heated at 850 ° C. to solidify the bonding material and the slurry. Thereby, the outer peripheral material layer 4 having a thickness of 0.5 mm was formed on the outer peripheral surface.

  As described above, the honeycomb structure 1 of this example could be manufactured. The honeycomb structure 1 of this example is shown in FIG. 9 at its end face. As shown in FIG. 9, the honeycomb structure 1 of the present example includes a substantially cylindrical honeycomb body 7 that divides a large number of protrusions extending in the axial direction, and an outer peripheral material layer formed on the outer peripheral surface of the honeycomb body 7. 4, and on the outer peripheral surface of the honeycomb body 7, there are grooves 60 extending in the axial direction formed by the outer peripheral material layer 4 entering.

  Also in the honeycomb structure 1 of the present example, the effect of suppressing separation of both at the interface between the honeycomb body 7 and the outer peripheral material layer 4 is exhibited.

FIG. 3 is a view showing a state when a honeycomb segment used in the honeycomb structure of Example 1 is formed. 1 is a diagram showing a honeycomb body of Example 1. FIG. 3 is a view showing an end face of a joined body of honeycomb bodies of Example 1. FIG. 3 is a view showing an end face of a honeycomb structure of Example 1. FIG. FIG. 6 is a view showing a honeycomb segment of Example 4. 10 is a view showing a honeycomb segment of Example 6. FIG. FIG. 10 is a view showing a honeycomb segment of Example 7. 10 is a view showing a honeycomb body of Example 8. FIG. 10 is a view showing an end face of a honeycomb structure of Example 8. FIG.

Explanation of symbols

1: Honeycomb structure 2: Honeycomb segment 3: Sealing material 4: Peripheral material layer 5: Bonding material layer 6: Recess 60, 61: Groove 62: Recessed portion 7: Honeycomb body

Claims (6)

A substantially columnar honeycomb body made of porous ceramics and partitioned in a number of cells extending in the axial direction;
A bonding layer made of ceramics bonded to the outer periphery of the honeycomb body;
A honeycomb structure having
The honeycomb body has a recess recessed from the outer peripheral surface formed on the outer peripheral surface,
The honeycomb structure characterized in that the ceramic is bonded to the inner surface of the concave portion of the bonding layer.   The honeycomb structure according to claim 1, wherein the recess has a depth of 1.0 mm or less.   The honeycomb structure according to any one of claims 1 to 2, wherein the concave portion includes a groove extending along an axial direction of the honeycomb body.   The honeycomb structure according to any one of claims 1 to 3, wherein the honeycomb body is a plurality of honeycomb bodies, and the bonding layer is a bonding material layer that bonds the plurality of honeycomb bodies.   The honeycomb structure according to any one of claims 1 to 4, wherein the bonding layer is an outer peripheral material layer formed on an outer periphery of the honeycomb body.   The honeycomb structure according to any one of claims 1 to 5, wherein the honeycomb body includes silicon carbide as a main component.

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