JP5390171B2 - Manufacturing method of honeycomb structure - Google Patents

Description

  The present invention relates to a method for manufacturing a honeycomb structure, and more particularly, to a method for manufacturing a honeycomb structure that can improve production efficiency and improve a raw material yield.

  Ceramic honeycomb structure with excellent heat resistance and corrosion resistance is used as a carrier or filter for catalyst devices used for environmental measures and recovery of specific materials in various fields such as chemistry, electric power, steel, etc. Has been. In particular, recently, a honeycomb structure has a plugged honeycomb structure by alternately plugging the cell openings on both end faces, and particulate matter (PM: particulate matter) discharged from a diesel engine or the like. It is actively used as a diesel particulate filter (DPF) that collects water. As a material for the honeycomb structure used in a high temperature and corrosive gas atmosphere, silicon carbide (SiC), cordierite, aluminum titanate (AT), etc. excellent in heat resistance and chemical stability are suitable. It is used.

Since silicon carbide has a relatively high coefficient of thermal expansion, if a honeycomb structure formed using silicon carbide as an aggregate is formed with a large volume, defects may occur due to thermal shock during use. In addition, defects may occur due to thermal shock when the collected particulate matter is removed by combustion. Furthermore, when a honeycomb structure having a large volume is produced, cracks due to temperature difference between the inside and outside may occur at the time of firing, so there is a problem that it must be slowly degreased and fired over many times as usual. there were. For this reason, when manufacturing a honeycomb structure formed of silicon carbide as an aggregate, a plurality of segments of a small plugged honeycomb structure are usually manufactured and the segments are joined. Then, one large joined body is produced, and the outer periphery thereof is roughly processed and ground to form a plugged honeycomb structure having a desired shape such as a cylindrical shape (see Patent Document 1). In addition, joining of a segment is performed using a joining material, a joining material is apply | coated to the side surface of a predetermined segment, and the several segment is joined by the side surfaces. Further, a method of extruding a honeycomb formed body having slits when manufacturing a honeycomb structure is disclosed (for example, see Patent Document 2).
JP 2003-291054 A JP 2001-170426 A

  When a honeycomb structure having a desired shape is manufactured by the method described in Patent Document 1, normally, a plurality of rectangular parallelepiped segments are joined to form one large rectangular parallelepiped joined body, and then the substantially desired shape is obtained. In order to achieve the desired shape, the outer periphery was roughly processed, and it was necessary to grind the honeycomb structure into a desired shape. Therefore, extra steps such as the outer peripheral roughing step and the grinding step were required. In addition, since the outer periphery is roughly processed and ground, the raw material yield is low. Moreover, when a honeycomb structure is manufactured by the method described in Patent Document 2, it is difficult to design a die for extrusion molding. Further, since the extruded molded body (honeycomb molded body) is easily deformed, it cannot be mass-produced.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for manufacturing a honeycomb structure capable of improving the production efficiency and the raw material yield.

  In order to solve the above-described problems, the present invention provides the following honeycomb structure manufacturing method.

[1] A forming raw material is extruded to form a honeycomb formed body having partition walls that partition and form a plurality of cells extending from one end face to the other end face that serve as a fluid flow path. A plurality of slits are formed in parallel with the direction in which the slits are formed to form a slit-formed honeycomb formed body, and the slit-formed honeycomb formed body is fired to form a slit-formed honeycomb fired body. And forming a notch so as to include at least one of the end faces and including the slit, and forming a partial segment assembly in which a plurality of partial segments are defined by the notch, and the partial segment is formed. by pre-Symbol slits formed in the aggregate of the filler is filled in the slit, loose between the partial segments adjacent A method for manufacturing a honeycomb structure, in which an impact portion is formed to obtain a honeycomb structure.

[2] The method for manufacturing a honeycomb structured body according to [1], wherein each of the slits formed before firing forms an opening on the end surface and does not form an opening on the outer peripheral surface.

[3] The method for manufacturing a honeycomb structured body according to [2], wherein each slit formed before firing forms an opening only on one end face.

[4] The method for manufacturing a honeycomb structured body according to [3], wherein a part of the plurality of slits opens on the one end face, and the remaining slits open on the other end face.

[5] The method for manufacturing a honeycomb structured body according to [2], wherein each of the slits formed before firing forms openings on both end faces.

[6] The method for manufacturing a honeycomb structured body according to [1], wherein each slit formed before firing forms an opening on an outer peripheral surface and does not form an opening on the end surface.

[7] The method for manufacturing a honeycomb structured body according to [6], wherein each slit formed before firing forms one opening on an outer peripheral surface.

[8] The method for manufacturing a honeycomb structured body according to [6], wherein each slit formed before firing forms two openings on the outer peripheral surface.

[9] The method for manufacturing a honeycomb structure according to any one of [1] to [8], wherein the slit formed in the slit-formed honeycomb fired body is formed so as to open also on the other end face side.

[10] The method for manufacturing a honeycomb structure according to any one of [1] to [8], wherein the slit formed in the slit-formed honeycomb fired body is formed so as to open only on the one end face side.

  According to the method for manufacturing a honeycomb structured body of the present invention, before extruding one honeycomb formed body and firing the obtained honeycomb formed body, the obtained honeycomb formed body is parallel to the cell extending direction. In order to produce a honeycomb structure by forming a plurality of slits, and then firing, forming notches to form aggregates of partial segments, and forming a buffer portion between the partial segments, the outer periphery is roughly processed Therefore, production efficiency can be improved and raw material yield can be greatly improved.

  Furthermore, according to the method for manufacturing a honeycomb structured body of the present invention, before firing the honeycomb formed body, a plurality of slits are formed in the honeycomb formed body in parallel with the cell extending direction. Since the stress due to the shrinkage difference caused by the temperature difference between the inside and outside of the molded body can be relaxed by the slit, no cracks are generated even if the degreasing and firing time is shortened.

  BEST MODE FOR CARRYING OUT THE INVENTION Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments and is within the scope of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on the general knowledge of vendors.

(1) One embodiment of a method for manufacturing a honeycomb structure:
As shown in FIGS. 1A and 1B, one embodiment of a method for manufacturing a honeycomb structure of the present invention is to extrude a forming raw material and from one end face 1 serving as a fluid flow path to the other end face 2. A honeycomb formed body 100 having partition walls 7 (see FIGS. 2 and 3) for partitioning and forming a plurality of cells 6 (see FIGS. 2 and 3) is formed, and one end face 1 side is formed on the honeycomb formed body 100. The slits 4 are formed in parallel with the cell extending direction to form the slit-formed honeycomb formed body 110, and the slit-formed honeycomb formed body 110 is fired. The slit-formed honeycomb fired body is formed, and the slit-formed honeycomb fired body is opened on at least one end face 1 side, and a slit 5 is formed so as to include the slit 4. A buffer portion is formed between the adjacent partial segments 3 by forming a partial segment assembly 120 in which the minute segment 3 is partitioned and filling the notch 5 formed in the partial segment assembly 120 with a filler. 8 is formed to obtain the honeycomb structure 130. The method for manufacturing a honeycomb structure of the present embodiment is an example in which each slit formed before firing forms an opening only on one end face and does not form an opening on the outer peripheral surface. A part of the plurality of slits (for example, one of the two slits) opens at one end face, and the remaining slit (the remaining one of the two slits). Is also a preferred embodiment. Moreover, while each slit forms an opening part in both end surfaces, the aspect which does not form an opening part in an outer peripheral surface is also a preferable aspect.

  Here, “the slit 5 is formed so as to include the slit 4” means that the space formed as the slit 4 is included in the space formed as the slit 5. Therefore, the portion (space) that was the “slit 4” in the slit-formed honeycomb formed body also becomes the “cut 5” in the assembly of the partial segments. In addition, the term “a plurality of slits” includes a case where two slits 4 intersect in a cross shape on one end face 1 as in the slit-formed honeycomb formed body 110 shown in FIG. 1A (in this case) Means “two slits”). Further, the “partial segment” is a segment formed by making a cut parallel to the central axis in one honeycomb molded body, and each partial segment is in a separated state, A notch is formed on one end face side, and the other end face side includes a part remaining without being formed with a notch, so that each partial segment is connected to the other end face side. FIG. 1A is a plan view schematically showing a process of forming a honeycomb structure in one embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 1B is a side view schematically showing a process of forming the honeycomb structure in one embodiment of the method for manufacturing a honeycomb structure of the present invention. Further, as shown in FIG. 1A, in the method for manufacturing a honeycomb structure of the present embodiment, openings of predetermined cells on one end face 1 of the honeycomb formed body 100 and openings of remaining cells on the other end face 2 are formed. It is preferable that plugged portions are plugged to form a plugged honeycomb formed body, and slits 4 are formed in the plugged honeycomb formed body to form a slit-formed honeycomb formed body 110.

  When manufacturing a honeycomb structure having a large cylindrical shape (for example, a cylindrical shape with a bottom diameter of 100 mm or more) made of a material having a high thermal expansion coefficient such as silicon carbide, in order to prevent damage due to a thermal shock at a high temperature. After producing a rectangular parallelepiped segment and joining it to produce a large rectangular parallelepiped joined body, the outer periphery is roughly ground using a device such as a bead saw and ground using a device such as a cam grinder (grinding) ) To form a cylindrical honeycomb structure. For this reason, an extra step such as a roughing step for the outer peripheral portion is required, and the outer periphery is roughly processed, so that the raw material yield is not high. On the other hand, in the method for manufacturing a honeycomb structure of the present embodiment, a cylindrical honeycomb molded body having a desired large size is manufactured by extrusion molding, so that a rectangular parallelepiped segment joining process and an outer peripheral portion are roughly processed. Since there is no process, the production efficiency is high and the raw material yield is also high. Also, when degreasing and firing a large cylindrical honeycomb formed body, the inside of the formed body becomes high temperature and cracks are likely to occur due to a temperature difference from the outer periphery of the formed body. It is necessary to perform degreasing and firing over time so that the temperature difference does not increase, but the honeycomb structure manufacturing method of the present embodiment forms a slit in the honeycomb formed body before degreasing and firing. Even if the temperature difference between the inside of the body and the outer periphery of the molded body increases, distortion due to the temperature difference can be alleviated by the slit. Therefore, the method for manufacturing a honeycomb structure of the present embodiment can perform degreasing and firing in a short time. Here, “rough machining” means that a joined body having a shape such as a rectangular parallelepiped is machined into a shape close to a desired shape by cutting the outer periphery thereof. Further, “grinding” means that the outer periphery of the roughly processed bonded body is further ground to finish with a desired shape and desired surface smoothness with high accuracy. Hereinafter, it demonstrates for every process.

(1-1) Production of honeycomb formed body;
First, a binder, a surfactant, a pore former, water and the like are added to a ceramic raw material to form a forming raw material. Ceramic raw materials include silicon carbide, silicon-silicon carbide based composite material, cordierite, mullite, alumina, titania, spinel, silicon carbide-cordierite based composite material, lithium aluminum silicate, aluminum titanate, iron-chromium-aluminum based It is preferably at least one selected from the group consisting of alloys. Among these, silicon carbide or silicon-silicon carbide based composite material is preferable. When a silicon-silicon carbide based composite material is used, a mixture of silicon carbide powder and metal silicon powder is used as a ceramic raw material. The content of the ceramic raw material is preferably 40 to 90% by mass with respect to the entire forming raw material.

  Examples of the binder include methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. Among these, it is preferable to use methyl cellulose and hydroxypropoxyl cellulose in combination. The binder content is preferably 3 to 15% by mass with respect to the entire forming raw material.

  The water content is preferably 7 to 45 mass% with respect to the entire forming raw material.

  As the surfactant, ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like can be used. These may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the surfactant is preferably 0 to 5% by mass with respect to the entire forming raw material.

  The pore former is not particularly limited as long as it becomes pores after firing, and examples thereof include starch, foamed resin, water absorbent resin, silica gel, and carbon. The pore former content is preferably 0 to 15% by mass with respect to the entire forming raw material.

  Next, the forming raw material is kneaded to form a clay. There is no restriction | limiting in particular as a method of kneading | mixing a shaping | molding raw material and forming a clay, For example, the method of using a kneader, a vacuum clay kneader, etc. can be mentioned.

  Next, the clay is molded to form a cylindrical honeycomb molded body 100 as shown in FIGS. 1A and 1B. The honeycomb formed body 100 has partition walls that partition and form a plurality of cells extending from one end surface 1 to the other end surface 2 that serve as a fluid flow path, and an outer peripheral wall 14 is disposed on the outermost periphery of the partition walls. Yes. The method for forming the kneaded clay to form the honeycomb formed body is not particularly limited, and a conventionally known forming method such as extrusion molding can be used. Preferred examples include a method of forming a honeycomb formed body by extrusion using a die having a desired cell shape, partition wall thickness, and cell density. As the material of the die, a cemented carbide which does not easily wear is preferable.

  Next, it is preferable to dry the obtained honeycomb formed body. The drying method is not particularly limited, and examples thereof include an electromagnetic heating method such as microwave heating drying and high-frequency dielectric heating drying, and an external heating method such as hot air drying and superheated steam drying. Among these, the entire molded body can be dried quickly and uniformly without cracks, and after drying a certain amount of moisture with an electromagnetic heating method, the remaining moisture is dried with an external heating method. It is preferable to make it. As drying conditions, it is preferable to remove moisture of 30 to 95% by mass with respect to the amount of moisture before drying by an electromagnetic heating method, and then to make the moisture to 3% by mass or less by an external heating method. As the electromagnetic heating method, dielectric heating drying is preferable, and as the external heating method, hot air drying is preferable. The drying temperature is preferably 90 to 180 ° C. The drying time is preferably 1 to 10 hours.

  Next, when the length in the central axis direction of the honeycomb molded body (the length in the cell extending direction) is not a desired length, it is preferable to cut both end faces (both ends) to a desired length. . The cutting method is not particularly limited, and examples thereof include a method using a double-headed circular saw cutter.

(1-2) Creation of a slit-formed honeycomb formed body;
Next, as shown in FIG. 1A and FIG. 1B, a plurality of slits 4 that are open on one end face 1 side but not on the other end face 2 are formed in the honeycomb formed body 100, thereby forming a slit-formed honeycomb formed body. 110 is produced.

  In the method for manufacturing a honeycomb structure of the present embodiment, as shown in FIGS. 2 and 3, the slits 4 are arranged in a row perpendicular to the extending direction of the cells 6, the cell rows 12 arranged in a row, and the partition walls 7. It is preferably formed so as to be longitudinally cut. When slits are formed in a row of cells arranged in two or more rows, the slits formed when forming an assembly of partial segments are wide, thereby thickening the buffer portion. If the buffer is thick, the pressure loss may increase when used as a filter for exhaust gas treatment. In addition, the slits 4 are preferably formed so as to continuously cut the rows of cells arranged in a row while cutting the partition walls, but so as to cut the rows of cells intermittently while cutting the partition walls. It may be formed. Thus, when the slit is formed while intermittently cutting the partition, the length of the “part where the partition is not cut” between the slits arranged in a row is preferably 5 mm or less. If the length of the part where the partition walls are not cut is longer than 5 mm, the effect of preventing cracking during degreasing and firing may be reduced. Further, in the method for manufacturing a honeycomb structure of the present embodiment, when the length of the “parts where the partition walls are not cut” is 5 mm or less, the two parts arranged in a row with the “parts where the partition walls are not cut” sandwiched therebetween Assume that the slit is a single slit. FIG. 2 is a schematic diagram showing a part of a cross section perpendicular to the cell extending direction, showing a slit-formed honeycomb formed body manufactured in the honeycomb structure manufacturing process in the honeycomb structure manufacturing method of the present embodiment. is there. FIG. 3 is a schematic diagram showing a part of a cross section perpendicular to the cell extending direction, showing a slit-formed honeycomb formed body manufactured in the manufacturing process of the honeycomb structure in the manufacturing method of the honeycomb structure of the present embodiment. is there.

  In the slit-formed honeycomb molded body 110, the slit formation pattern in a cross section perpendicular to the cell extending direction is preferably a pattern (shape) in which two slits intersect in a cross shape. Furthermore, the intersection of the two slits is preferably located in the central region of the cross section perpendicular to the cell extending direction of the slit-formed honeycomb formed body 110. Here, “the central region in the cross section perpendicular to the cell extending direction of the slit-formed honeycomb formed body” means that the cross-sectional shape (cross-sectional shape) perpendicular to the cell extending direction of the slit formed honeycomb formed body is circular. In this case, it is a circular region whose center is the center of the circle and whose radius is 50% of the radius of the circle. Further, when the cross-sectional shape is an ellipse, it is a circular region whose center is the center of the ellipse and whose radius is 50% of the minor axis of the ellipse. Further, when the cross-sectional shape is another shape, the center of gravity is the center of gravity, and the cross-sectional shape is similar to the cross-sectional shape and the area is 25% of the cross-sectional area.

  In the slit-formed honeycomb formed body 110, the lower limit value of the length of the slit 4 in the cell extending direction is preferably 70%, more preferably 85%, with respect to the length of the slit-formed honeycomb formed body. 90% is particularly preferable. If the lower limit is shorter than 70%, cracks are likely to occur during degreasing and firing, and it may be necessary to lengthen the degreasing and firing time. The upper limit value of the length of the slit 4 in the cell extending direction is preferably 99%, more preferably 98%, relative to the length of the slit-formed honeycomb formed body. If it is longer than 99%, the connected portions are easily broken, and if the connected portions are broken, the slit-formed honeycomb formed body may be separated. The length of the slit in the cell extending direction does not need to be constant in one slit, and at least a part may be in the above range, but it is preferable that all the parts are in the above range. . Furthermore, it is preferable that the length of the slit 4 in the cell extending direction is constant in one slit. Similarly, when there are a plurality of slits, it is sufficient that at least one slit is within the above range, but it is preferable that all are within the above range. The thickness (width) of the slit 4 is preferably within the thickness range of one cell. The lower limit value of the thickness (width) of the slit 4 is preferably 0.3 mm, and more preferably 1.0 mm. If it is thinner than 0.3 mm, cracks may easily occur during degreasing and firing. The upper limit value of the thickness (width) of the slit 4 is preferably 3.0 mm, and more preferably 1.5 mm. If it is thicker than 3.0 mm, the pressure loss when gas flows through the honeycomb structure may increase. The thickness of the slit does not need to be constant in one, and at least a part may be in the above range, but it is preferable that all the slits are in the above range. Furthermore, the thickness of the slit is preferably constant. Similarly, in the plurality of slits, at least one slit may be in the above range, but it is preferable that all the slits are in the above range.

  In the method for manufacturing a honeycomb structured body of the present embodiment, the slit 4 opens only on one end face, and no opening is formed on the outer peripheral surface 11 of the slit formed honeycomb formed body. When firing, a honeycomb structure with good shape accuracy can be produced without deformation of the slit-formed honeycomb formed body. If the slit is formed so as to have openings on both the end face and the outer peripheral face, the slit-formed honeycomb formed body may be deformed during firing.

In the slit-formed honeycomb molded body 110, the lower limit value of the standard area of each pre-firing partition region 13 which is a region partitioned by a plurality of slits formed before firing in a cross section perpendicular to the cell extending direction is 9 cm ^2. Preferably, it is 12 cm ² . When the honeycomb structure is smaller than 9 cm ² , small segments are aggregated, and pressure loss when used as a DPF may be high. Moreover, it is preferable that the upper limit of each standard area of the division area | region 13 before baking which is an area | region divided by the some slit formed before baking is 110 cm < ² >, and it is further more preferable that it is 75 cm < ² >. If it is wider than 110 cm ² , cracks are likely to occur during degreasing and firing, and therefore it may be necessary to lengthen the time for degreasing and firing. Here, the “standard area” is orthogonal when two slits are formed in a cross shape in a cross section orthogonal to the cell extending direction of the formed honeycomb body of the slit (see FIG. 1). It means a rectangular area having two lines (two orthogonal line segments) from the intersection of two slits to the end of each slit (each different slit). Further, when the two slits are not orthogonal, it means an area of a parallelogram having two lines from the intersection of the slits to the end of each slit. In addition, when the pre-firing partition region is not in the shape of an eel, but in another shape, it means the area surrounded by the slits. In the cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body shown in FIG. 1A, before the firing, if the cross section is not completely partitioned by the slit (the slit does not reach the outer peripheral surface) The partition region 13 is a region formed by extending both end portions of the two slits 4 to the outer peripheral surface. In this case, the slit can be extended to the outermost peripheral portion to form one pre-firing partition region when the distance from the end of the slit to the outermost peripheral portion is 5 mm or less. When the distance between the end of the slit and the outer peripheral surface exceeds 5 mm, the pre-firing compartment area is grasped (formed) as having no compartment by the slit. When the slit intersects with another slit, the pre-firing partition region is grasped (formed) assuming that there is no portion from the intersecting portion to the end of the slit. The same applies to the distance between the end of each slit and the other slit. When the distance between the end of the slit and the other slit is 5 mm or less, the pre-firing partition region is different from the end of the slit. The region is formed to extend to the slit. When there are a plurality of pre-firing compartments, more than half of them are preferably in the above range, and all are preferably in the above range.

  A cell in which no slit is formed between each end of the plurality of slits formed before firing and the outermost peripheral portion (outer peripheral wall) of the formed honeycomb body in the cross section perpendicular to the cell extending direction. 1 to 5 are preferably present side by side, more preferably 1 to 3 are present side by side. Since the distance from the end of the slit to the outermost peripheral portion is within such a range, when the slit-formed honeycomb formed body is degreased and fired, it can be prevented from collapsing due to high temperature. If the number of cells arranged from the end of the slit to the outermost periphery is more than five, cracks from the end of the slit toward the outermost periphery may occur during firing. In the case of a crack extending straight from the end of the slit to the outermost peripheral portion, there may be no problem when a cut is formed in that portion later. Moreover, in the cross section orthogonal to the cell extending direction, the distance from each end of the plurality of slits formed before firing to the outermost periphery of the slit-formed honeycomb formed body is preferably 1 to 5 mm, and preferably 1 to 3 mm. Is more preferable. Since the distance from the end of the slit to the outermost peripheral portion is in such a range, when the slit-formed honeycomb molded body is degreased and fired, it can be prevented from collapsing due to high temperature, and the obtained honeycomb structure can be obtained. It is possible to prevent an increase in pressure loss when exhaust gas or the like is circulated. In addition, “in the cross section perpendicular to the cell extending direction, the distance from the end of the slit to the outermost periphery of the formed honeycomb body of the slit” refers to the distance from the end of the slit to the outer peripheral surface. .

  Next, with respect to the slit-formed honeycomb formed body, it is preferable to form plugged portions at openings of predetermined cells on one end face and openings of remaining cells on the other end face. When plugged portions are formed in the honeycomb formed body, the obtained honeycomb structure becomes a plugged honeycomb structure. The method for plugging is not particularly limited, and examples thereof include the following methods. After the sheet is attached to one end face of the honeycomb formed body, a hole is opened at a position corresponding to a cell where a plugging portion of the sheet is to be formed. At this time, when the opening portion of the slit is formed on the end face, it is preferable not to make a hole in the portion closing the slit so that the plugging slurry does not enter the slit. Then, the end surface of the honeycomb molded body on which the sheet is pasted is immersed in a slurry for plugging which is a slurry of the constituent material of the plugging portion, and the cell to be plugged through the hole opened in the sheet The plugging slurry is filled into the opening end. And about the other end surface of the honeycomb formed body, the plugged portion was formed in the same manner as the method of plugging the one end surface with respect to the cells in which the plugged portion was not formed on one end surface. Form (fill with plugging slurry). As the constituent material of the plugged portion, the same material as that of the honeycomb formed body is preferably used. The plugging portion may be formed after the slit is formed in the honeycomb formed body, but may be performed before the slit is formed. This is because if the slit is formed after forming the plugged portion, the entry of the processing jig may be prevented by the plugged portion when the slit is formed in the honeycomb formed body with the processing jig. It is. When forming the opening of the slit on the outer peripheral surface of the honeycomb molded body, the plugged portion does not hinder the formation of the slit, so the plugged portion may be formed before the slit formation, It may be formed later.

(1-3) Production of a slit-formed honeycomb fired body;
Next, the slit-formed honeycomb molded body 110 is preferably fired to obtain a slit-formed honeycomb fired body. When firing, it is preferable to form a calcined body by degreasing (temporary firing) in order to remove the binder and the like before the main firing. The calcined body is preferably fired to form a slit-formed honeycomb fired body. In the method for manufacturing a honeycomb structured body of the present embodiment, the term “firing” means the main firing. Therefore, after the honeycomb formed body is temporarily fired, slits may be formed, and then the main firing may be performed. Pre-baking is preferably performed in an air atmosphere at a maximum temperature of 400 to 500 ° C. for 0.5 to 10 hours. There are no particular limitations on the method of temporary firing and main firing, and firing can be performed using an electric furnace, a gas furnace, or the like. As for the conditions for the main firing, in the case of a silicon-silicon carbide based composite material, it is preferable to heat at 1300 to 1500 ° C. for 1 to 10 hours in an inert atmosphere of argon. Here, “main firing” means an operation for melting the silicon in the forming raw material of the calcined body and bonding it with silicon carbide to ensure a predetermined strength.

(1-4) Production of an assembly of partial segments;
Next, the slit-formed honeycomb fired body is opened to at least one end face 1 side, and a slit 5 is formed so as to include the slit 4, and a plurality of partial segments 3 are partitioned by the slit 5. A group of segments 120 is formed. By forming the cuts 5 in this manner, the resulting honeycomb structure can be made to have a structure in which a plurality of partial segments are joined together, so that a honeycomb structure excellent in thermal shock resistance can be obtained.

  The notch 5 is formed along the cell extending direction (parallel to the central axis). In the partial segment assembly 120 shown in FIG. 1A, the notch 5 is formed so as to cut the outer peripheral wall 14 and open to the other end face 2. The cut 5 is preferably formed in this way, but may be formed without cutting the outer peripheral wall 14, or may be formed so as not to open in the other end surface 2. When the notch 5 is formed so as not to open in the other end surface 2, after filling the notch 5 with a filler, a portion near the other end surface 2 where the notch 5 is not formed may be cut off. In this case, the obtained honeycomb structure has a structure in which the buffer portion 8 is disposed from one end face 1 to the other end face 2 in the same manner as the honeycomb structure 130 shown in FIG. 1A.

  In the method for manufacturing a honeycomb structure of the present embodiment, the slit-formed honeycomb molded body 110 is formed with the cuts 5 reaching from the one end face 1 to the other end face 2 to form the partial segment aggregate 130. Each partial segment is in a separated state. In this case, each partial segment may be in a disjoint state. However, as shown in FIGS. 4A and 4B, the portions 22 corresponding to the partial segments on both end faces 1 and 2 of the slit-formed honeycomb molded body 110 are formed. An assembly of partial segments is formed by gripping both end faces 1 and 2 of the slit-formed honeycomb molded body 110 with the gripping tools 21 for gripping each, and forming a slit reaching the other end face 2 in the slit-formed honeycomb molded body 110. Is preferably formed. Thereby, even after forming the slit reaching the other end surface 2 from the one end surface 1 to the slit-formed honeycomb molded body 110, each partial segment is fixed by the gripping tool 21, so it is not separated. In this state, the buffer portion can be easily formed in the next step, and the production efficiency can be improved. Further, in the method for manufacturing a honeycomb structure of the present embodiment, the integrally formed slit-formed honeycomb molded body 110 is fired, and then the cuts 5 are formed to form the partial segment aggregate 130. In addition, it is possible to prevent confusion between the directions of the segments (inlet side and outlet side). In other words, each segment (partial segment) needs to be joined with the direction of the inlet side end and the outlet side end aligned, but when forming the segments separately and joining them, In some cases, the inlet side end portions of some segments and the outlet side end portions of the remaining segments are joined (confused) in the same direction. The manufacturing method of the honeycomb structure of the present embodiment can prevent this. FIG. 4A is a side view schematically showing a state in which the both end surfaces 1 and 2 of the slit-formed honeycomb formed body 110 are gripped by the gripping tool 21. FIG. 4B is a plan view schematically showing a slit-formed honeycomb molded body 110 viewed from one end surface 1 side, showing a portion 23 on one end surface 1 with which the gripping tool 21 abuts.

  As shown in FIG. 1A and FIG. 1B, the segment segment assembly 120 has a linear shape on one end face 1 and both ends of the notch 5 (both end portions of the notch 5 on the one end face 1). When forming the notch 5 having a structure that reaches the outer peripheral surface (a structure that also cuts the outer peripheral wall), it is preferable to use a notch forming device such as a disk-shaped multi-grinding stone, a multi-blade saw, a multi-wire saw or the like. The disc-shaped multi-grinding stone is formed by arranging a plurality of disc-shaped grinding stones on the side of the outer periphery of the slit-forming honeycomb molded body 110 so that they are parallel to each other, and rotating each of them while rotating each of them. The slit-formed honeycomb molded body 110 is cut in parallel by moving to one end face 1. For example, a product name: high-speed surface grinder manufactured by ELB can be used. In the multi-blade saw, a plurality of bar-shaped (or plate-shaped) grindstones are arranged on one end face 1 so as to be parallel to each other, and reciprocatingly moving in parallel with one end face 1. The slit-formed honeycomb molded body 110 is cut in the direction from one end face 1 to the other end face 2. For example, trade name: blade saw manufactured by Nomura Seisakusho Co., Ltd. can be used. The multi-wire saw has a plurality of wire-shaped grindstones arranged on one end face 1 so as to be parallel to each other, and reciprocally moved in parallel to one end face 1 or continuously in one direction. While moving, the slit forming honeycomb molded body 110 is cut from one end face 1 toward the other end face 2, and for example, trade name: Multi-wire saw manufactured by Takatori Co., Ltd. can be used. .

  As in the case of the slits 4 shown in FIGS. 2 and 3, the cuts 5 are formed by vertically cutting the cell rows 12 aligned in a row while cutting the partition walls 7 in a cross section orthogonal to the extending direction of the cells 6. Preferably it is formed. The reason is the same as in the case of the slit 4. Further, the lower limit value of the thickness (width) of the slit 14 is preferably 0.3 mm, and more preferably 1.0 mm. The upper limit value of the thickness (width) of the cut 14 is preferably 3.0 mm, and more preferably 1.5 mm. When the thickness is less than 0.3 mm, the buffering effect between the partial segments 3 and 3 may be reduced, and when the thickness is more than 3.0 mm, the pressure loss when the gas flows through the honeycomb structure may be increased.

Regarding the size of the partial segment 3, the lower limit value of the standard area of the cross section perpendicular to the central axis direction is preferably 3 cm ² , and more preferably 7 cm ² . The upper limit value of the standard area of the cross section perpendicular to the central axis direction is preferably 100 cm ² , and more preferably 16 cm ² . If it is smaller than 3 cm ² , the pressure loss when gas flows through the honeycomb structure may be increased, and if it is larger than 100 cm ² , the effect of preventing breakage of the partial segment 3 may be decreased.

(1-5) Production of honeycomb structure;
Next, by filling the notch 5 formed in the partial segment assembly 120 with a filler, the buffer portion 8 is formed between the adjacent partial segments 3 to obtain the honeycomb structure 130. The buffer portion 8 is preferably disposed in 70% or more of the space formed between the partial segments, more preferably 90% or more, and 100%. Is particularly preferred. When the buffer portion 8 is disposed in 100% of the space formed between the partial segments, the joint strength is improved because the adjacent partial segments are disposed on the entire bonding surfaces facing each other. Is preferable. The buffer 8 plays a role of buffering (absorbing) the volume change when each partial segment is thermally expanded and contracted, and also serves to join the partial segments. Therefore, “the buffer portion 8 is formed between the adjacent partial segments” can be said to be “joining the adjacent partial segments via the buffer portion 8”.

  As a method of forming the buffer portion 8, as shown in FIG. 4A, when the slit-formed honeycomb formed body 110 is gripped by the gripping tool 21, the notched portion has a constant thickness even after the slit is formed. Therefore, a method in which a filler is dispersed in a dispersion medium such as water to form a slurry and is filled in the cut. At this time, the thickness of the cut portion held by the gripping tool 21 becomes the thickness of the buffer portion 8. When filling the slurry into the slit, it is preferable to put the assembly 120 of partial segments fixed by a gripping tool into a sealed container and wrap a tape or the like around the outer periphery so that the slurry does not leak from the outer periphery. The slurry is preferably filled using an injection device such as a syringe or an elongated nozzle. In the case of using such an injection apparatus, when the assembly 120 of partial segments is large, it can be filled without applying high pressure by filling the slurry from a plurality of locations. Examples of the material of the tape wound around the outer periphery of the partial segment assembly 120 include a material that does not transmit water such as polyester. Desorption can also be facilitated by a thing like an airbag (for example, product name: air gripper manufactured by Bridgestone Corporation). In order to prevent the slurry from flowing into the cell, it is preferable to improve workability by performing masking such as attaching a tape to the opening end of the cell. In this case, if the partial segment aggregate 120 is filled with the slurry in a state where the partial segment aggregate 120 is stationary, if the partial segment aggregate 120 is porous, the dispersion medium is absorbed by the partition walls and the slurry cuts into the interior 5. May not spread evenly. Therefore, in such a case, it is preferable to press-fit the slurry while vibrating the assembly 120 of partial segments by the vibration device. As the vibration device, for example, a product name: small vibration tester manufactured by Asahi Seisakusho Co., Ltd. can be used. Further, in order to make the slurry more easily and uniformly enter the notch, it is preferable to hydrate the inner wall of the notch (the outer peripheral wall of the partial segment). Examples of the hydrous treatment include a method of spraying steam. After the slurry is pressed into the slit, it is preferable to perform drying at 100 ° C. or higher.

  Furthermore, when the gripping tool 21 is used, as a method of forming the buffer portion 8, the filler is formed into a tape shape, a plurality of tape-like fillers are filled into the cuts, and then heat treatment is performed. Thus, the buffer unit 8 can be used. The method of forming the filler into a tape shape is not particularly limited, and examples include a method of mixing a filler, a binder, a surfactant, water, and the like into a forming raw material and forming the tape into a tape shape by a tape forming method. Can do. Moreover, as a method of forming the buffer portion 8, a method of forming the buffer portion 8 by filling a notch with a powdery filler and then sealing the upper and lower portions with cement, adhesive, or the like. Can be mentioned. The powdery filler can be filled into notches by tapping.

  Further, when the gripping tool 21 is not used, as a method of forming the buffer portion 8, a slurry is formed by dispersing the filler in a dispersion medium such as water, and is applied to the joining surfaces of the partial segments. Or the method of affixing the said tape-shaped filler on a joining surface, and joining each segment after that is mentioned.

  Examples of the filler include inorganic fibers, colloidal silica, clay, SiC particles, an organic binder, a foamed resin, and a slurry in which water is added to a dispersant and kneaded. When the filler is molded into a tape shape and inserted into the notch, it is preferable to use a material that foams by heat treatment as the filler, and after the filler is inserted into the notch, the notched honeycomb structure is heated. . Examples of the material that foams by the heat treatment include a foamed urethane resin.

  After forming the honeycomb structure, the end face may be polished in order to increase the parallelism of the both end faces.

(1-6) outer periphery coating treatment;
After forming the honeycomb structure, it is preferable to perform outer periphery coating. By performing the outer periphery coating treatment, there is an advantage of improving the accuracy of the irregularities on the outer periphery of the honeycomb. Examples of the outer periphery coating treatment include a method in which an outer periphery coating material is applied to the outer periphery of the honeycomb structure and dried. As the outer periphery coating material, a mixture of inorganic fiber, colloidal silica, clay, SiC particles, organic binder, foamed resin, dispersant, water, or the like can be used. Moreover, the method of applying the outer periphery coating material is not particularly limited, and examples thereof include a method of coating the honeycomb structure with a rubber spatula while rotating on the potter's wheel.

(2) Honeycomb structure:
The honeycomb structure obtained by one embodiment of the method for manufacturing a honeycomb structure of the present embodiment has partition walls that partition and form a plurality of cells extending from one end face to the other end face that serve as a fluid flow path, A honeycomb structure portion in which a plurality of partial segments are defined by a plurality of cuts extending in the central axis direction from one end face, and a buffer portion disposed between adjacent partial segments are provided. And an outer periphery coat | court may be formed so that the outer periphery of the whole partition may be covered. It is also preferable that the honeycomb structure is a plugged honeycomb structure (plugged honeycomb structure) in which openings of predetermined cells on one end face and openings of remaining cells on the other end face are plugged.

  The honeycomb structure constituting the honeycomb structure of the present embodiment preferably has the entire shape of the honeycomb structure finally obtained. For example, a desired shape such as a cylindrical shape or an elliptical shape can be used. Moreover, as for the magnitude | size of a honeycomb structure part, for example, when it is cylindrical shape, it is preferable that the diameter of a bottom face is 50-450 mm, and it is still more preferable that it is 100-350 mm. The length of the honeycomb structure portion in the central axis direction is preferably 50 to 450 mm, and more preferably 100 to 350 mm. As the material of the honeycomb structure part, ceramic is preferable, and since it is excellent in strength and heat resistance, silicon carbide, silicon-silicon carbide based composite material, cordierite, mullite, alumina, spinel, silicon carbide-cordierite based composite material, More preferably, it is at least one selected from the group consisting of lithium aluminum silicate, aluminum titanate, and iron-chromium-aluminum alloys. Among these, silicon carbide or silicon-silicon carbide based composite material is particularly preferable. Since silicon carbide has a relatively high coefficient of thermal expansion, a honeycomb structure formed using silicon carbide as an aggregate may cause defects due to thermal shock when used, but the honeycomb structure of the present invention By forming a plurality of partial segments by a plurality of cuts and disposing a buffer portion as in the structure, the thermal expansion of silicon carbide is buffered by the buffer portion, and the occurrence of defects in the honeycomb structure can be prevented. Play.

  The honeycomb structure part is preferably porous. The lower limit value of the open porosity of the honeycomb structure part is preferably 30%, and more preferably 40%. The upper limit value of the open porosity of the honeycomb structure part is preferably 80%, and more preferably 65%. By setting the open porosity in such a range, there is an advantage that the pressure loss can be reduced while maintaining the strength. If the open porosity is less than 30%, the pressure loss may increase. If the open porosity exceeds 80%, the strength may decrease and the thermal conductivity may decrease. The open porosity is a value measured by the Archimedes method.

  In the honeycomb structure portion, the lower limit value of the average pore diameter is preferably 5 μm, and more preferably 7 μm. The upper limit value of the average pore diameter is preferably 50 μm, and more preferably 35 μm. By setting the average pore diameter in such a range, there is an advantage that particulate matter (PM) can be effectively collected. If the average pore diameter is less than 5 μm, clogging may easily occur due to particulate matter (PM). When the average pore diameter exceeds 50 μm, particulate matter (PM) may pass through without being collected by the filter. The average pore diameter is a value measured with a mercury porosimeter.

  When the material of the honeycomb structure part is silicon carbide, it is preferable that the average particle diameter of the silicon carbide particles is 5 to 100 μm. By setting it as such an average particle diameter, there exists an advantage that it is easy to control to the porosity and pore diameter suitable for a filter. When the average particle size is smaller than 5 μm, the pore diameter is too small, and when it is larger than 100 μm, the porosity may be small. If the pore diameter is too small, clogging is likely to occur due to particulate matter (PM), and if the porosity is too small, pressure loss may increase. The average particle diameter of the raw material is a value measured according to JIS R 1629.

The cell shape of the honeycomb structure part (cell shape in a cross section perpendicular to the central axis direction (cell extending direction) of the honeycomb structure part) is not particularly limited, and for example, a triangle, a quadrangle, a hexagon, an octagon, A circular shape or a combination thereof can be given. When plugging is provided, a combination of an octagon and a quadrangle is also a suitable example. The partition wall thickness of the honeycomb structure part is preferably 50 to 2000 μm. If the partition wall thickness is less than 50 μm, the strength of the honeycomb structure may be reduced, and if it is more than 2000 μm, the pressure loss may be increased. Cell density of the honeycomb structure section is not particularly limited, preferably 0.9 to 311 cells / cm ^2, more preferably 7.8 to 62 cells / cm ^2.

  The buffer portion constituting the honeycomb structure of the present embodiment is preferably disposed so as to fill the entire cutout space of the honeycomb structure portion.

Further, the thermal expansion coefficient of the obtained honeycomb structure is preferably 1 × 10 ⁻⁶ / ° C. or more, more preferably 2 × 10 ^{−6 to} 7 × 10 ⁻⁶ / ° C. According to the method for manufacturing a honeycomb structure of the present invention, even such a honeycomb structure having a large thermal expansion coefficient can be made into a honeycomb structure having high thermal shock resistance.

(3) Other embodiment of manufacturing method of honeycomb structure:
As shown in FIGS. 5A and 5B, another embodiment of a method for manufacturing a honeycomb structure of the present invention is a cylindrical honeycomb as in the embodiment of the method for manufacturing a honeycomb structure of the present invention. A formed body 200 is manufactured, and a slit-formed honeycomb formed body 210 is manufactured. Thereafter, the slit-formed honeycomb molded body 210 is fired to produce a slit-formed honeycomb fired body. Thereafter, the slit-formed honeycomb fired body is parallel to the central axis from one end face 15 (along the cell extending direction). A partial segment aggregate 220 is formed by forming a cut 17 that extends and remains without cutting the other end face 16 side. Thereafter, the buffer portion 18 is formed between the partial segments of the partial segment assembly 220 to produce the buffer portion-provided partial segment 230. After that, as shown in FIGS. 6A and 6B, the other end face 16 side (non-notch forming portion) 20 of the buffer portion disposing portion segment 230 left without being formed is cut, and the cut surface 19 is one of the cut surfaces 19. The honeycomb structure 240 is obtained by cutting off so as to be parallel to the end surface 15 and forming the buffer portion 18 in the notch 17 reaching from the one end surface 15 to the other end surface (cut surface 19). FIG. 5A is a plan view schematically showing a process until a honeycomb structure is formed in another embodiment of the method for manufacturing a honeycomb structure of the present invention, and FIG. 5B is a honeycomb structure of the present invention. In other embodiment of the manufacturing method of a structure, it is the side view which showed typically the process until the middle of the formation of a honeycomb structure. FIG. 6A schematically shows a process of forming a honeycomb structure by cutting off the other end portion left without forming a cut in another embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 6B is a plan view, and FIG. 6B shows a process of forming a honeycomb structure by cutting off the other end portion left without forming a cut in another embodiment of the method for manufacturing a honeycomb structure of the present invention. It is the side view shown typically.

  According to the method for manufacturing a honeycomb structure of the present embodiment, since the partial segment aggregate 220 is connected on the other end face 16 side, it is like a gripping tool as in the case where the partial segments are separated. Since it is not necessary to fix each partial segment, the operation of forming the cut and the operation of forming the buffer portion can be performed more easily, and the production efficiency can be further improved.

(3-1) Production of an assembly of partial segments;
The manufacturing method of the partial segment assembly 220 in the manufacturing method of the honeycomb structure of the present embodiment is the same as the manufacturing method of the partial segment assembly of the embodiment of the manufacturing method of the honeycomb structure of the present invention. The honeycomb fired body is formed with a notch 17 extending in parallel to the central axis from one end face 15 toward the other end face 16 and leaving the other end face 16 side without cutting, so that a partial segment aggregate 220 is formed. To form. The length (cut depth) of the cut 17 in the central axis direction (cell penetration direction) is preferably 70 to 99% of the length in the central axis direction of the honeycomb formed body 100. If it is shorter than 70%, the other end face side (non-notch forming portion) 20 left without forming the notch 14 which is cut off in a later step becomes large, and the raw material yield may be lowered. If it is longer than 99%, the non-notch forming portion 20 may be easily broken. It should be noted that whether or not the non-cut forming portion is broken depends largely on the material strength, shape, and the like, and it is preferable that the non-cut forming portion is small as long as the problem of cracking does not occur. Further, when it is not intended to form the non-cut forming portion 20, the cut may be formed so as to reach the other end face as in the embodiment of the honeycomb structure of the present invention. . The length of the cut does not have to be constant in one piece, and at least a part may be in the above range, but it is preferable that all the cuts are in the above range. Furthermore, the length of the cut is preferably constant in one. Similarly, when there are a plurality of cuts, it is sufficient that at least one is within the above range, but it is preferable that all are within the above range.

  The thickness (width) of the notch 17 is preferably in the range of the thickness of one cell. As a specific length, the lower limit is preferably 0.3 mm, and more preferably 1.0 mm. Moreover, it is preferable that an upper limit is 3.0 mm, and it is still more preferable that it is 1.5 mm. When the thickness is less than 0.3 mm, the buffering effect between the partial segments 3 and 3 may be reduced, and when the thickness is more than 3.0 mm, the pressure loss when the gas flows through the honeycomb structure may be increased. The thickness of the cut does not have to be constant in one piece, and at least a part may be in the above range, but it is preferable that all the parts are in the above range. Furthermore, it is preferable that the thickness of the cut is constant in one. Similarly, when there are a plurality of cuts, it is sufficient that at least one is within the above range, but it is preferable that all are within the above range. The slit width and the slit width may be the same or different as long as they are within one cell.

(3-2) Production of a buffer portion disposition partial segment;
As a method of forming the buffer portion 18 in the partial segment aggregate 220 and forming the buffer portion-provided partial segment 230, the honeycomb structure according to the embodiment of the present invention is manufactured. In the step, it is preferable to use the same method as that in the case where the buffer portion is formed in the assembly of the partial segments. However, in the method for manufacturing a honeycomb structured body of the present embodiment, the assembly of partial segments has a non-cut portion, and each partial segment does not break apart, so there is no need to use a gripping tool. In addition, the filler used for forming the buffer portion is preferably the same as the filler used in the honeycomb structure manufacturing step in one embodiment of the honeycomb structure manufacturing method of the present invention.

(3-3) Production of honeycomb structure;
Next, as shown in FIG. 6A and FIG. 6B, the other end face side (non-notch forming portion) 20 of the buffer portion disposition portion segment 230 left without being formed with the cut surface 19 The honeycomb structure 240 in which the buffer portion 18 is formed in the notch 17 reaching from the one end face 15 to the other end face (cut face 19) is obtained. The position of the cut surface 19 is a position where all of the buffer portions 18 in the buffer portion disposition partial segment 230 are cut, and the center axis direction length of the resulting honeycomb structure 240 is a desired length. Is preferred. Moreover, it is preferable to use a disk-shaped grindstone, a blade saw, a wire saw, etc. for cutting-off operation. When plugging, when cutting off, it is necessary to leave the required amount of plugging at least on the end face side even after cutting. Must be filled. Alternatively, plugging may be performed after cutting off.

  Each characteristic of the honeycomb structure obtained by the manufacturing method of the honeycomb structure of the present embodiment is the same as that of the honeycomb structure of the present invention obtained by the embodiment of the manufacturing method of the honeycomb structure of the present invention. It is preferable that the same as in the case of.

(4) Still another embodiment of the method for manufacturing a honeycomb structure:
Still another embodiment of the method for manufacturing a honeycomb structure according to the present invention is the same as the other embodiment of the method for manufacturing a honeycomb structure according to the present invention, up to the buffer portion arrangement segment 230 (see FIGS. 5A and 5B). And the buffer portion disposition partial segment 230 is formed as a honeycomb structure as a final product. Therefore, the honeycomb structure obtained by the manufacturing method of the honeycomb structure of the present embodiment has the same structure as the buffer portion arrangement segment 230 shown in FIGS. 5A and 5B, and serves as a fluid flow path. A partition having a plurality of cells extending from one end surface 15 to the other end surface 16 and extending in the central axis direction from one end surface 15, and having a plurality of portions by a plurality of notches 17 not reaching the other end surface 16 A honeycomb structure portion in which segments are formed and a buffer portion 18 disposed in the entire cut 17 are provided. Such a honeycomb structure can also be suitably used as a catalyst carrier, a filter, and the like.

  In the honeycomb structure manufactured by the method for manufacturing a honeycomb structure of the present embodiment, since the plurality of partial segments are partitioned as described above, the partial segments can be formed small, and the partial segments caused by thermal shock can be formed. Breakage can be prevented. Furthermore, since the partial segment is formed via the buffer part, the thermal expansion of the partial segment is buffered by the buffer part, and damage to the partial segment can be prevented.

  In the honeycomb structure manufactured by the method for manufacturing a honeycomb structure of the present embodiment, the length of the cut in the central axis direction of the honeycomb structure portion (cut depth) is 25 of the length in the central axis direction of the honeycomb structure portion. % Or more, preferably 25 to 99%, more preferably 25 to 75%. When particulate matter is burned and removed after the particulate matter is collected by the honeycomb structure, it is within a range from the end face on the gas outflow side to a length of 25% of the length in the central axis direction of the honeycomb structure (25% The region where the temperature is highest is present. Therefore, when the gas is allowed to flow in from the other end face of the honeycomb structure of the present embodiment and the gas is allowed to flow out from the one end face, the cut is 25% of the length in the central axis direction of the honeycomb structure portion from the one end face. Since the partial segment exists in the region where the thermal shock is large at the highest temperature, the honeycomb structure can be more effectively prevented from being damaged. Further, when the cut is formed in the whole of the honeycomb structure portion in the central axis direction (from one end surface to the other end surface), the buffer portion is disposed in the cut, so that the fluid passes through the honeycomb structure. Sometimes the pressure loss increases. On the other hand, when the cut is 99% or less of the length in the central axis direction of the honeycomb structure portion, the cut is provided in the range of 1% or more on the other end face side of the honeycomb structure portion. Since there is no buffer portion, it is possible to suppress an increase in pressure loss. The length of the cut does not have to be constant in one piece, and at least a part may be in the above range, but it is preferable that all the cuts are in the above range. Furthermore, the length of the cut is preferably constant in one. Similarly, when there are a plurality of cuts, it is sufficient that at least one is within the above range, but it is preferable that all are within the above range.

  Further, in another embodiment of the method for manufacturing a honeycomb structure of the present invention, the above-mentioned “the buffer portion disposition portion segment 230 (see FIGS. 5A and 5B) is made into a honeycomb structure as a final product” is performed. In the embodiment, as shown in FIG. 7, the obtained honeycomb structure is formed in the vicinity of the outer periphery with a long length in the central axis direction for the cut (long cut) 34 passing through the vicinity of the central axis of the honeycomb structure 300. The cut (short cut) 34 is formed by shortening the length in the central axis direction. The resulting honeycomb structure 300 has partition walls that partition and form a plurality of cells extending from one end surface 31 to the other end surface 32 serving as a fluid flow path, and extends from one end surface 31 in the central axis direction. This includes a honeycomb structure part 36 in which a plurality of partial segments 33 are defined by a plurality of cuts 34 that do not reach the other end face 32, and a buffer part 35 disposed throughout the cuts 34. In the honeycomb structure 300 shown in FIG. 7, the notch 34 passing near the central axis is formed to have a long length in the central axis direction. When the particulate matter collected by the honeycomb structure is burned and removed, the periphery of the central axis becomes higher than the vicinity of the outer periphery, so that the formation of such a configuration effectively damages the partial segment 33 near the central axis. Can be prevented. Here, the notch passing through the vicinity of the central axis refers to the notch passing through the range from the center to 50% of the radius of the outer circumference circle in the cross section perpendicular to the central axis when the honeycomb structure has a cylindrical shape. . FIG. 7 is a perspective view schematically showing a honeycomb structure manufactured by still another embodiment of the method for manufacturing a honeycomb structure of the present invention. Further, in the honeycomb structure 300 shown in FIG. 7, four parallel cuts 34 formed at equal intervals and three parallel cuts formed so as to be orthogonal to the four cuts. Spacing cuts 34 are provided. In the method for manufacturing a honeycomb structure of the present embodiment, the length of the long cut (slit) in the central axis direction of the honeycomb structure portion (cut depth) is 70 to 99 of the length in the central axis direction of the honeycomb structure portion. % Is preferred. In addition, the length (cut depth) of the short cut (slit) in the central axis direction of the honeycomb structure portion is preferably 25 to 75% of the length in the central axis direction of the honeycomb structure portion.

  In addition, as in the honeycomb structure shown in FIGS. 8 to 10, the one having the largest area among the partial segments constituting the outer periphery of the honeycomb structure portion on one end face where the cut is formed is the honeycomb structure. It is preferable that the area is larger than that of the smallest area among the remaining partial segments located in the central portion. When the particulate matter collected by the honeycomb structure is removed by combustion, the remaining partial segment (partial segment located in the central part) 33b located at the central part has a higher temperature than the partial segment 33a constituting the outer periphery. Therefore, by arranging the partial segment with a small area in the central portion in this way, it is possible to effectively prevent the partial segment located in the central portion from being damaged. Here, the “partial segment located in the center” refers to a partial segment excluding the partial segment constituting the outer periphery of the honeycomb structure portion from the entire partial segment. As described above, when the area of the partial segment located in the central portion on one end face is small, the pressure loss of the honeycomb structure tends to increase. Therefore, the center of the honeycomb structure portion of the notch 34 (buffer portion 35). The length in the axial direction is particularly preferably 25 to 75% of the length in the central axis direction of the honeycomb structure portion. By making the length of the cut 34 in the central axis direction of the honeycomb structure portion 75% or less, an increase in pressure loss can be prevented. In the honeycomb structure 320 shown in FIG. 8, the partial segment 33 b located at the center of one end face 31 is smaller than the partial segment 33 a constituting the outer periphery because it is finely divided into squares. In the honeycomb structure 330 shown in FIG. 9, the partial segment 33 b located at the center of one end face 31 is smaller than the partial segment 33 a constituting the outer periphery because it is finely partitioned into rectangles. In the honeycomb structure 340 shown in FIG. 10, the partial segment 33 b located at the center of one end face 31 is smaller than the partial segment 33 a constituting the outer periphery due to a finely divided shape. 8 to 10 are plan views schematically showing a honeycomb structure manufactured by still another embodiment of the method for manufacturing a honeycomb structure of the present invention, as viewed from one end face side.

  Here, at one end surface 31 as formed in the honeycomb structure portion of the honeycomb structure 320 shown in FIG. 8, at least one of both ends does not reach the outer peripheral surface of the honeycomb structure portion 34 ( In the case of having a closed structure cut), it is preferable to use an ultrasonic vibration blade method, a low frequency vibration blade method, or the like. Incision processing by the vibration blade method is the longitudinal direction or center of a rod-like or plate-like blade extending in the longitudinal direction, or a cylindrical blade having the same cross-sectional shape as the cross-sectional shape of the notch (cross-sectional shape perpendicular to the central axis direction). The tip in the axial direction is brought into contact with one end face 31 of the honeycomb molded body, and a cut is formed in the honeycomb fired body while ultrasonically vibrating the blade. Since cutting is performed using the tip of a rod-shaped, plate-shaped or cylindrical blade, it is possible to form a cut at any position on one end face 31 of the honeycomb fired body. As a vibration blade type processing apparatus, for example, a product name: ultrasonic processing machine manufactured by JEOL Ltd., a product of Miniter Corporation, a product name: Minimo One series polyter handpiece ultrasonic polishing machine can be used. Further, the cutting process by the low-frequency vibration blade method can be performed in the same manner as in the case of the ultrasonic vibration blade method. The difference between the ultrasonic vibration blade method and the low frequency blade method is that the ultrasonic blade method vibrates the blade with ultrasonic waves, whereas the low frequency vibration blade method uses an eccentric motor, cam mechanism, eccentric weight mechanism, etc. Is to vibrate.

(5) Still another embodiment of the method for manufacturing a honeycomb structure:
In another embodiment of the method for manufacturing a honeycomb structure of the present invention, a slit-formed honeycomb fired body is manufactured in the same manner as in the embodiment of the method for manufacturing a honeycomb structure of the present invention, and FIG. As shown in the figure, the end surface 41 side from the one end surface 41 is formed so as to partition and form a plurality of partial segments 43 while leaving the outermost peripheral portion including the outermost peripheral portion 46 without cutting in the obtained honeycomb formed body. A notch 44 extending in parallel with the central axis toward the central axis is formed to form an assembly 420 of partial segments, which are adjacent to each other in the same manner as in the embodiment of the method for manufacturing a honeycomb structure of the present invention. The buffer portion 45 is formed between the partial segments to obtain the honeycomb structure 430. In the honeycomb structure 430 shown in FIG. 11, four parallel, equally spaced cuts 44 and three, parallel, equally spaced cuts 44 formed perpendicular to the four cuts. A notch 44 is provided. In the manufacturing method of the honeycomb structure of the present embodiment, when the cut 44 is formed in the honeycomb formed body, the outermost peripheral portion including the outermost peripheral portion 46 is left without being cut. Since the outer peripheral wall without cut is formed so as to surround the entire segment, and the buffer portion is not exposed on the outer peripheral surface, it is not necessary to perform outer peripheral grinding processing and outer peripheral coating processing, thereby improving production efficiency. Further improvement is possible. Further, when it is desired to further reduce the irregularities on the outer peripheral surface and form a smoother outer peripheral surface, it is preferable to perform outer peripheral grinding and / or outer peripheral coating. Thus, the outermost peripheral portion left without being cut becomes an outer peripheral wall in the obtained honeycomb structure. When forming the cut, as shown in FIG. 11, the outermost partial segment may be connected to the outermost peripheral part, or the inside (inner side) may be circular along the outermost peripheral part. The partial segment located on the outermost side and the outermost peripheral portion may be cut out to have a separated shape.

  The thickness of the outermost peripheral portion left without being cut is preferably 0.1 to 5 mm, and more preferably 0.3 to 1.0 mm. If the thickness is less than 0.1 mm, the outermost peripheral portion may be easily cracked in the step after the formation of the cut and when the obtained honeycomb structure is used. If it is thicker than 5 mm, the pressure loss may increase.

  The method for forming the cuts for forming the inside of the honeycomb molded body while leaving the outermost peripheral part without cutting is the “blocking structure cuts” as formed in the honeycomb structure part 36 of the honeycomb structure 320 shown in FIG. It is preferable to use a method similar to the method of forming "." By this method, a notch can be formed so as to partition a plurality of partial segments while leaving the outermost peripheral portion without cutting.

  Further, in the method for manufacturing a honeycomb structure of the present embodiment, the notches formed reach from one end face to the other end face as in the case of the assembly 120 of partial segments shown in FIGS. 1A and 1B. It may also be a cut that leaves the other end face side without being cut as in the case of the partial segment assembly 220 shown in FIGS. 5A and 5B. When a notch reaching from one end face to the other end face is formed, the resulting honeycomb structure has a structure like the honeycomb structure 430a shown in FIG. 12, and the notch left without cutting the other end face side is formed. When formed, the obtained honeycomb structure has a structure like a honeycomb structure 430b shown in FIG. 12 and 13 are perspective views schematically showing a honeycomb structure manufactured by still another embodiment of the method for manufacturing a honeycomb structure of the present invention. When the cut reaches from the one end surface to the other end surface, it is preferable to form the cut and the buffer portion while holding the partial segment and the outermost peripheral portion using a gripping tool. Also, if the cut is left without cutting the other end face side, cut the other end face side left without being cut so that the cut surface is parallel to one end face, It is preferable to form a honeycomb structure in which a buffer portion is formed in a notch reaching from one end face to the other end face. In this case, when cutting off the other end face remaining without being cut, it is preferable to cut off the outermost peripheral portion together so that a single cut surface is formed.

(6) Still another embodiment of the method for manufacturing a honeycomb structure:
In each of the embodiments of the method for manufacturing a honeycomb structured body of the present invention described above, the slits formed in the honeycomb formed body are open at the end face. However, each slit is formed on the outer peripheral surface of the honeycomb formed body. An embodiment in which one or two openings are formed and no opening is formed on the end face is also a preferred embodiment. The effect of forming the slit is the same as that of the embodiment of the method for manufacturing the honeycomb structure described above.

  FIG. 14A is a plan view seen from one end face side, schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in still another embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 14B is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in still another embodiment of the method for manufacturing a honeycomb structured body of the present invention. As shown in FIG. 14A and FIG. 14B, in the method for manufacturing a honeycomb structure of the present embodiment, the formation pattern of the slits 61 formed in the slit-formed honeycomb formed body 520 is two in the cross section orthogonal to the cell extending direction. This is a formation pattern in which the slits 61 are orthogonal. The slit 61 does not open at both end faces of the slit-formed honeycomb formed body 520, and four openings 63 are formed on the outer peripheral surface (outermost peripheral portion 62).

  Even when a slit having an opening only on the outer peripheral surface (outermost peripheral portion 62) is formed in the honeycomb molded body, each component excluding the slit forming method is the same as that of the above-described method for manufacturing a honeycomb structure of the present invention. It is preferable that it is the same as each component in embodiment. However, in each of the embodiments of the method for manufacturing a honeycomb structure of the present invention described above, “a mode in which when the slit is formed in the slit-formed honeycomb fired body, the outermost peripheral portion of the slit-formed honeycomb fired body is left without being cut. "Is excluded.

  In the method for manufacturing a honeycomb structured body according to the present embodiment, since the opening portions of the slits are not formed on both end faces of the honeycomb formed body, the honeycomb formed body is prevented from being deformed by the restraining force of both end portions. The lower limit value of the length of the slit formed in the honeycomb formed body in the cell extending direction is preferably 70%, more preferably 85%, with respect to the length of the slit-formed honeycomb formed body. % Is particularly preferred. Further, the upper limit value of the length of the slit formed in the honeycomb formed body in the cell extending direction is preferably 99%, more preferably 98%, relative to the length of the slit formed honeycomb formed body. . If it is shorter than 70%, cracks are likely to occur during degreasing and firing, and it may be necessary to lengthen the degreasing and firing time. If it is longer than 99%, the slit-formed honeycomb formed body may be divided (split) during firing.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
SiC powder and metal Si powder are mixed at a mass ratio of 80:20 as ceramic raw materials, and this is mixed with methyl cellulose and hydroxypropoxymethyl cellulose as molding aids, and starch and water-absorbing resin as pore formers, respectively. An agent and water were added and kneaded, and a clay was prepared with a vacuum kneader.

The obtained columnar clay is formed into a honeycomb shape using an extrusion molding machine, dried by high-frequency dielectric heating, dried at 120 ° C. for 5 hours using a hot air dryer, and both end surfaces are cut by a predetermined amount. Thus, a cylindrical honeycomb molded body having a partition wall thickness of 310 μm, a cell density of 46.5 cells / cm ² (300 cells / square inch), a bottom diameter of 155 mm, and a length of 162 mm was obtained.

  About the obtained honeycomb formed body, plugged portions were formed at the end portions of the respective cells so that adjacent cells were sealed at opposite end portions and both end surfaces had a checkered pattern. As the plugging filler, the same material as that of the honeycomb formed body was used. The depth of the plugging portion (depth in the cell extending direction) was 7 mm on one end face side and 12 mm on the other end face side. After plugging, the plugged honeycomb formed body was heated at 120 ° C. for 5 hours using a hot air dryer.

  With respect to the obtained honeycomb formed body, a plurality of slits that were opened on one end face side and not opened on the other end face were formed to obtain a slit-formed honeycomb formed body 510 as shown in FIGS. 15A and 15B. . As shown in FIG. 15A and FIG. 15B, the shape of the slit is a cross shape intersecting at the center in the cross section orthogonal to the cell extending direction, and the length in the cell extending direction is the length of the slit-formed honeycomb formed body. Of 97%. In the cross section perpendicular to the cell extending direction, the distance from the end of the slit to the outermost peripheral portion 55 of the slit-formed honeycomb formed body was 5 mm (3 cells). The slit was formed by cutting the partition so as to cut the row of cells aligned in a row. At this time, in the cross section orthogonal to the cell extending direction, the partition parallel to the slit extending direction was not broken, so that one row of cells was formed, and only “the partition orthogonal to the slit extending direction” was cut. The slit processing was performed using an ultrasonic polishing machine manufactured by Miniter. The blade used for processing was made of stainless steel having a thickness of 0.5 mm, a width of 15 mm, a length of 200 mm, and a tip angle of 10 °. FIG. 15A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 1 as viewed from one end face side. FIG. 15B is a side view schematically showing the slit-formed honeycomb formed body produced in the intermediate stage in Example 1. FIG.

Thereafter, the temperature was raised to 450 ° C. over about 20 hours (hr) using an air furnace equipped with a deodorizing device in the air atmosphere (especially in the range of 200 to 300 ° C. where the organic components were decomposed slowly). Then, it was held at 450 ° C. for 5 hours, and then degreased by naturally cooling to 100 ° C. over 5 hours in a furnace (30 hr degreasing). The degreasing conditions are shorter than normal conditions (60 hours in total). “Normal conditions” is a degreasing method (60 hr degreasing) in which the temperature is raised to 450 ° C. over about 50 hours, then held at 450 ° C. for 5 hours, and then cooled to 100 ° C. over 5 hours in the furnace. . Thereafter, the porous slit was fired at about 1450 ° C. for 24 hours (main firing) in an Ar inert atmosphere (temperature rising 10 hours, holding 4 hours, temperature falling 10 hours), and SiC crystal particles were bonded with Si. A formed honeycomb fired body was obtained. The average pore diameter of the slit-formed honeycomb fired body was 13 μm, and the porosity was 41%. The average pore diameter is a value measured by a mercury porosimeter, and the porosity is a value measured by the Archimedes method. After the main firing, whether or not “cut” and “deformation” occurred in the slit-formed honeycomb formed body was visually observed. The results are shown in Table 1. Here, it is determined that “cutting” has occurred when there is a crack outside the slit formation site, and “deformation” has occurred when the shape before firing is changed to a shape that is not similar. It should be noted that the subsequent manufacturing (manufacturing of the honeycomb structure) was not performed for those that were cut or deformed after the main firing. Moreover, the standard area of the division area | region before baking was 56.25 (7.5 cm x 7.5 cm) cm < ² >. In addition, each length (7.5 cm) in the above “7.5 cm × 7.5 cm” is the distance from the intersection of the slits to the end face of the slit in the cross section orthogonal to the cell extending direction of the slit-formed honeycomb formed body. Show.

  The obtained slit-formed honeycomb fired body was cut to form an aggregate of partial segments. The cutting process was performed using the above-described ultrasonic vibration processing machine. 28, three parallel cuts 72 and three parallel cuts 72 perpendicular to the three cuts 72 are formed on one end surface 71 so that the honeycomb structure 530 shown in FIG. 28 is formed. A partial segment 73 of the book was formed (cut pattern: 3 × 3). The interval between each parallel cut was 24 cells. The length between the notches at this time was about 36 mm. The length (cut depth) of each slit in the central axis direction of the slit-formed honeycomb fired body was 97% of the length of the slit-formed honeycomb fired body in the cell extending direction. The cut depth was the same for all cuts. The width of the cut was set to one cell (the partition was cut so as to cut the row of cells aligned in a row to form the cut). FIG. 28 is a plan view schematically showing the honeycomb structure manufactured in Example 1 as seen from one end face side.

  The buffer material 74 was formed by filling the partial segment aggregate in a slurry state with a filler. As the filler, a mixture of aluminosilicate inorganic fibers and SiC particles was used. As a slurry containing a filler, a slurry containing 30 parts by mass of water, 30 parts by mass of an aluminosilicate inorganic fiber, and 30 parts by mass of SiC particles was used with respect to 100 parts by mass of the filler. When filling the slurry into the cut, the outer periphery of the assembly of the partial segments was fixed with an epoxy resin and pressed from above. Then, it dried on 140 degreeC and the conditions for 2 hours using the hot air dryer. After drying, the outer periphery was processed using a lathe so as to remove the outer periphery by 3 mm from the outer periphery. Further, the other end face side of the aggregate of the partial segments provided with the buffer portion was cut by 5 mm to obtain a honeycomb structure before outer periphery coating in which the buffer portion was exposed on the other end face side. Further, one end face of the honeycomb structure before the outer periphery coating was polished by 2 mm, and the parallelism with respect to the other end face cut by 5 mm was obtained. The length of the obtained honeycomb structure in the cell extending direction was 155 mm.

  A coating material was applied to the entire outer peripheral surface of the obtained honeycomb structure before the outer periphery coating, and dried at 700 ° C. to obtain a honeycomb structure. As the coating material, a slurry obtained by mixing silicon carbide particles, colloidal silica, ceramic fibers, an inorganic binder, and an organic binder was used. The applied coating material had a thickness of 0.3 mm. Ten honeycomb structures were manufactured by the above method. Further, in order to confirm the difference in occurrence of “cut” due to the degreasing time, a honeycomb structure was manufactured by the same method as the above method except that the degreasing was performed under the above “normal conditions” (60 hr degreasing). did. Ten honeycomb structures were prepared by degreasing for 60 hours. Therefore, a total of 20 honeycomb structures were produced.

  The obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and there is no defect even in an internal defect test in which smoke is introduced from one end face and the leakage method is confirmed with a laser. Was confirmed. The results are shown in Table 1. In Table 1, the “slice” and “deformation” columns indicate the number of times “slice” and “deformation” occurred for 10 honeycomb formed bodies. For example, when “cut” occurs twice during the production of the honeycomb molded body 10 times, “2/10” is described. In addition, “deformation” was evaluated for a honeycomb formed body manufactured by performing “30 hr degreasing”.

(Example 2)
The slit formation pattern is orthogonal to the three parallel slits 54 and the three slits 54 in a cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 511 shown in FIGS. 16A and 16B. In the case of Example 1 except that the length of each slit 54 in the cell extending direction is 70% of the length of the slit-formed honeycomb formed body. In the same manner, a total of 20 honeycomb structures were produced. In the cross section orthogonal to the cell extending direction, the distance from the end of the slit 54 to the outermost peripheral portion 55 of the slit-formed honeycomb formed body was 5 mm (3 cells). The obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and there is no defect even in an internal defect test in which smoke is introduced from one end face and the leakage method is confirmed with a laser. Was confirmed. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. The standard area of the pre-firing compartment area was 13.69 (3.7 cm × 3.7 cm) cm ² . FIG. 16A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 2 as seen from one end face side. FIG. 16B is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 2. FIG.

(Example 3)
The formation pattern of the slits 54 intersects at the center and reaches the outermost peripheral part 55 in the cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 512 shown in FIGS. 17A and 17B ( The distance between the end of the slit 54 and the outermost peripheral portion 55 of the slit-formed honeycomb molded body is 0 mm), and the length of each slit 54 in the cell extending direction is the length of the slit-formed honeycomb molded body. Except for 90%, a total of 20 honeycomb structures were produced in the same manner as in Example 1. The honeycomb structure in which no “deformation” occurred in the obtained honeycomb structure was not defective in appearance, such as cracks and cell deformation, and smoke was introduced from one end face to prevent leakage. In the internal defect test confirmed by laser, it was confirmed that there was no defect. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. The standard area of the pre-firing compartment area was 56.25 (7.5 cm × 7.5 cm) cm ² . FIG. 17A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 3 as seen from one end face side. FIG. 17B is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 3.

Example 4
The formation pattern of the slits 54 is a cross shape that intersects at the center in the cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 513 shown in FIGS. 18A and 18B. Two portions that are not formed are formed so that each of the linear slits 54 is divided into three parts, and the length in the cell extending direction is set to 95% of the length of the slit-formed honeycomb formed body. Except for the above, a total of 20 honeycomb structures were produced in the same manner as in Example 1. The honeycomb structure in which no “deformation” occurred in the obtained honeycomb structure was not defective in appearance, such as cracks and cell deformation, and smoke was introduced from one end face to prevent leakage. In the internal defect test confirmed by laser, it was confirmed that there was no defect. In the cross section orthogonal to the cell extending direction, the distance from the end of the slit 54 to the outermost peripheral portion 55 of the slit-formed honeycomb formed body was set to 0 mm. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. The standard area of the pre-firing compartment area was 56.25 (7.5 cm × 7.5 cm) cm ² . FIG. 18A is a plan view schematically showing a slit-formed honeycomb formed body formed in an intermediate stage in Example 4 as seen from one end face side. FIG. 18B is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 4.

(Example 5)
The shape of the honeycomb formed body is an elliptical (major axis 185 mm, minor axis 102 mm) in a cross section perpendicular to the cell extending direction, and the slit forming pattern of the slit 54 is shown in FIGS. 19A and 19B. A total of 20 honeycomb structures were produced in the same manner as in Example 1 except that the cross-section intersecting at the center in the cross section orthogonal to the cell extending direction as in 514 was used. The obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and there is no defect even in an internal defect test in which smoke is introduced from one end face and the leakage method is confirmed with a laser. Was confirmed. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. The standard area of the pre-firing compartment area was 41.13 (8.8 cm × 4.7 cm) cm ² . FIG. 19A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 5 as seen from one end face side. FIG. 19B is a side view schematically showing the slit-formed honeycomb formed body produced in the middle stage in Example 5.

(Example 6)
The slit formation pattern is a cross shape intersecting at the center in a cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 513 shown in FIGS. 14A and 14B, and has four openings on the outer peripheral surface. A total of 20 honeycomb structures were produced in the same manner as in Example 1 except that the shape was such that it had a shape (having no openings on both end faces). The obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and there is no defect even in an internal defect test in which smoke is introduced from one end face and the leakage method is confirmed with a laser. Was confirmed. The slit having the opening only on the outer peripheral surface was formed by starting cutting of the partition wall from a predetermined position on the outer peripheral surface with an ultrasonic processing machine so as to penetrate to the outer peripheral surface on the opposite side. After forming the slit with an ultrasonic machine, the protrusions in the slit (the remaining portion of the cut partition wall) were removed using a 0.6 mm thick saw blade. The thickness of the slit was 1 mm, and the length of the slit in the cell extending direction was 90% of the length of the slit-formed honeycomb formed body. Further, the distance between the slit and the one end face was 5% of the length of the slit-formed honeycomb formed body. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. The standard area of the pre-firing compartment area was 56.25 (7.5 cm × 7.5 cm) cm ² .

(Example 7)
The formation pattern of the slits 54 is a cross shape intersecting at the center in the cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 515 shown in FIGS. 20A and 20B, and the standard area of the pre-firing partition region is set to 108.0 (12.0 cm × 9.0 cm) cm ^2, and the length in the cell extending direction was set to 95% of the length of the slit-formed honeycomb formed body, in the same manner as in Example 1. A total of 20 honeycomb structures were produced. The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 20A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 7 as seen from one end face side. FIG. 20B is a side view schematically showing the slit-formed honeycomb formed body produced in the middle stage in Example 7. FIG.

(Example 8)
The formation pattern of the slits 54 is a cross shape intersecting at a position slightly deviated from the center in a cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 516 shown in FIGS. 21A and 21B. Example 1 except that the standard area of the region was 90.25 (9.5 cm × 9.5 cm) cm ² and the length in the cell extending direction was 95% of the length of the slit-formed honeycomb formed body. A total of 20 honeycomb structures were produced in the same manner as in the case. The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 21A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 8 as seen from one end face side. FIG. 21B is a side view schematically showing the slit-formed honeycomb formed body produced in the middle stage in Example 8.

Example 9
The formation pattern of the slits 54 is a cross shape intersecting at a position slightly deviated from the center in a cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 517 shown in FIGS. 22A and 22B. Example 5 except that the standard area of the region was 56.0 (7.0 cm × 8.0 cm) cm ² and the length in the cell extending direction was 80% of the length of the slit-formed honeycomb formed body. A total of 20 honeycomb structures were produced in the same manner as in the case. The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 22A is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 9 as seen from one end face side. FIG. 22B is a side view schematically showing a slit-formed honeycomb formed body produced in the middle stage in Example 9.

(Example 10)
The formation pattern of the slits 54 is a cross shape intersecting at a position slightly deviated from the center in a cross section orthogonal to the cell extending direction as in the slit-formed honeycomb formed body 518 shown in FIGS. 23A and 23B. A total of 20 honeycomb structures were produced in the same manner as in Example 5 except that the standard area of the region was 62.5 (12.5 cm × 5.0 cm) cm ² . The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. In the same manner as in Example 1, it was confirmed that the slit-formed honeycomb formed body was “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 23A is a plan view from one end face side, schematically showing a slit-formed honeycomb formed body produced at an intermediate stage in Example 10. FIG. FIG. 23B is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 10.

(Example 11)
Except that the slit 54 has a pattern in which the length in the cell extending direction is 50% of the length of the slit-formed honeycomb formed body as in the slit-formed honeycomb formed body 519 shown in FIGS. 24A and 24B. In the same manner as in Example 1, a total of 20 honeycomb structures were produced. The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. The slit-formed honeycomb formed body was confirmed to be “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 24A is a plan view schematically showing the slit-formed honeycomb formed body produced in Example 11 as seen from one end face side. 24B is a side view schematically showing the slit-formed honeycomb formed body produced in Example 11. FIG.

(Example 12)
In the cross section orthogonal to the cell extending direction, the distance from the end of the slit to the outermost periphery of the slit-formed honeycomb formed body is 12 mm, and the standard area of the pre-firing partition region is 53.29 (7.3 cm × 7.3 cm). ) A total of 20 honeycomb structures were produced in the same manner as in Example 1 except that the thickness was changed to cm ² . The honeycomb structure in which no “cuts” occurred in the obtained honeycomb structure has no defects such as cracks and cell deformation in appearance, and smoke is introduced from one end face. It was confirmed that there was no defect even in the internal defect test for confirming with laser. The slit-formed honeycomb formed body was confirmed to be “cut” and “deformed” after the main firing. The results are shown in Table 1.

(Comparative Example 1)
As shown in FIG. 25A and FIG. 25B, the slit-formed honeycomb molded body 521 is formed in the same manner as in Example 1 except that the slit 54 has a single pattern that passes through the center in the cross section orthogonal to the cell extending direction. 20 in total were produced. The slit-formed honeycomb formed body was confirmed to be “cut” and “deformed” after the main firing. The results are shown in Table 1. FIG. 25A is a plan view schematically showing the slit-formed honeycomb formed body produced in Comparative Example 1 as seen from one end face side. FIG. 25B is a side view schematically showing the slit-formed honeycomb formed body produced in Comparative Example 1.

(Comparative Example 2)
As in the honeycomb molded body 522 shown in FIGS. 26A and 26B, a total of 20 honeycomb molded bodies were produced in the same manner as in Example 1 except that no slit was formed. Regarding the honeycomb formed body, it was confirmed whether or not “cut” and “deformation” occurred after the main firing. As a result, “cut” occurred in each case, and thus no honeycomb structure was produced. The results are shown in Table 1. FIG. 26A is a plan view schematically showing the honeycomb formed body produced in Comparative Example 2 as seen from one end face side. 26B is a side view schematically showing the honeycomb formed body produced in Comparative Example 2. FIG.

(Comparative Example 3)
As in the honeycomb molded body 523 shown in FIGS. 27A and 27B, a total of 20 honeycomb molded bodies were produced in the same manner as in Example 5 except that no slit was formed. Regarding the honeycomb formed body, it was confirmed whether or not “cut” and “deformation” occurred after the main firing. As a result, “cut” occurred in each case, and thus no honeycomb structure was produced. The results are shown in Table 1. FIG. 27A is a plan view schematically showing a honeycomb formed body produced in Comparative Example 3 as seen from one end face side. FIG. 27B is a side view schematically showing the honeycomb formed body produced in Comparative Example 3. FIG.

  In any of the manufacturing methods of the honeycomb structures of Examples 1 to 12, in order to extrude a honeycomb formed body having a shape close to the shape of the finally obtained honeycomb structure, a plurality of rectangular pillar-shaped honeycomb segments are separately extruded. It can be seen that the raw material yield is greatly reduced when compared with the conventional method in which the outer periphery is roughly processed after being molded and joined.

  From Table 1, it can be seen that the slit-formed honeycomb molded body produced in the intermediate stage in the manufacturing method of the honeycomb structures of Examples 1 to 6 has no occurrence of cutting even when the degreasing time is as short as 30 hours. . Some of the slit-formed honeycomb molded bodies produced in the intermediate stage in the manufacturing methods of the honeycomb structures of Examples 7 to 12 had creases, but the occurrence of creases can be reduced by extending the degreasing time. Recognize. On the other hand. The honeycomb formed bodies obtained by the honeycomb structure manufacturing method of Comparative Examples 1 to 5 (slit formation) were broken when the degreasing time was as short as 30 hours, and cracking occurred even when the degreasing time was further extended. It can be seen that is hardly reduced.

  Further, from Table 1, the honeycomb structure obtained by the method for manufacturing the honeycomb structure of Example 3 was deformed. This is because the slit formation pattern has an opening on the end surface and reaches the outer peripheral surface in a cross section perpendicular to the cell extending direction (the slit opens on the outer peripheral surface of the slit-formed honeycomb formed body). Therefore, it is considered that the original shape was somewhat difficult to maintain during degreasing and firing. Therefore, it can be seen that the slit is preferably formed so as to have an opening only on either the end face or the outer peripheral face.

  The method for manufacturing a honeycomb structure of the present invention is suitably used as a carrier for a catalytic device or a filter used for environmental measures or recovery of specific materials in various fields such as chemistry, electric power, and steel. A honeycomb structure that can be used can be utilized for efficient production.

FIG. 3 is a plan view schematically showing a process of forming a honeycomb structure in one embodiment of a method for manufacturing a honeycomb structure of the present invention. 1 is a side view schematically showing a process of forming a honeycomb structure in one embodiment of a method for manufacturing a honeycomb structure of the present invention. In one embodiment of a method for manufacturing a honeycomb structure of the present invention, a slit-formed honeycomb formed body manufactured in the manufacturing process of the honeycomb structure is shown, and a schematic view showing a part of a cross section orthogonal to the cell extending direction. is there. In one embodiment of a method for manufacturing a honeycomb structure of the present invention, a slit-formed honeycomb formed body manufactured in the manufacturing process of the honeycomb structure is shown, and a schematic view showing a part of a cross section orthogonal to the cell extending direction. is there. It is a side view which shows typically the state which held the both end surfaces of the slit formation honeycomb fabrication object with the holding tool. FIG. 3 is a plan view schematically showing a slit-formed honeycomb formed body as viewed from one end surface side, showing a portion on one end surface with which a gripping tool comes into contact. FIG. 6 is a plan view schematically showing a process until a honeycomb structure is formed in another embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 5 is a side view schematically showing a process until a honeycomb structure is formed in another embodiment of the method for manufacturing a honeycomb structure of the present invention. FIG. 6 is a plan view schematically showing a process of forming a honeycomb structure by cutting off the other end portion left without forming a cut in another embodiment of a method for manufacturing a honeycomb structure of the present invention. . FIG. 5 is a side view schematically showing a process of forming a honeycomb structure by cutting off the other end portion left without forming a cut in another embodiment of a method for manufacturing a honeycomb structure of the present invention. . FIG. 6 is a perspective view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 6 is a plan view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention, as viewed from one end face side. FIG. 6 is a plan view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention, as viewed from one end face side. FIG. 6 is a plan view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention, as viewed from one end face side. FIG. 6 is a perspective view schematically showing a process of forming a honeycomb structure in still another embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 6 is a perspective view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 6 is a perspective view schematically showing a honeycomb structure manufactured by still another embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 10 is a plan view seen from one end face side, schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in still another embodiment of a method for manufacturing a honeycomb structure of the present invention. FIG. 6 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in still another embodiment of the method for manufacturing a honeycomb structure of the present invention. 1 is a plan view seen from one end face side, schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 1. FIG. FIG. 3 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 1. FIG. 3 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 2 as viewed from one end face side. FIG. 4 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 2. [Fig. 6] Fig. 6 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 3 as viewed from one end face side. FIG. 6 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 3. [Fig. 6] Fig. 6 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 4 as viewed from one end face side. FIG. 10 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 4. FIG. 10 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 5 as viewed from one end face side. FIG. 10 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 5. [Fig. 10] Fig. 10 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 7 as viewed from one end face side. FIG. 10 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 7. Fig. 10 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 8 as viewed from one end face side. Fig. 10 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 8. 10 is a plan view seen from one end face side, schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 9. FIG. FIG. 10 is a side view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 9. In Example 10, it is the top view seen from one end surface side which shows typically the slit formation honeycomb fabrication object created in the middle stage. In Example 10, it is a side view which shows typically the slit formation honeycomb molded object produced in the intermediate | middle stage. FIG. 10 is a plan view schematically showing a slit-formed honeycomb formed body produced in an intermediate stage in Example 11 as viewed from one end face side. In Example 11, it is a side view which shows typically the slit formation honeycomb molded object created in the intermediate | middle stage. FIG. 3 is a plan view schematically showing a slit-formed honeycomb formed body produced in Comparative Example 1 as viewed from one end face side. 3 is a side view schematically showing a slit-formed honeycomb formed body produced in Comparative Example 1. FIG. FIG. 6 is a plan view schematically showing a honeycomb formed body produced in Comparative Example 2 as seen from one end face side. 10 is a side view schematically showing a honeycomb formed body produced in Comparative Example 2. FIG. [Fig. 9] Fig. 9 is a plan view schematically showing a honeycomb formed body produced in Comparative Example 3 as seen from one end face side. 10 is a side view schematically showing a honeycomb formed body produced in Comparative Example 3. FIG. 1 is a plan view schematically showing a honeycomb structure manufactured in Example 1 as viewed from one end face side. FIG.

Explanation of symbols

1: one end face, 2: the other end face, 3: partial segment, 4: slit, 5: notch, 6: cell, 7: partition wall, 8: buffer portion, 11: outer peripheral surface, 12: row of cells, 13 : Partition area before firing, 14: outer peripheral wall, 15: one end face, 16: the other end face, 17: notch, 18: buffer part, 19: cut surface, 20: non-notch part, 21: gripping tool, 22: Part corresponding to the partial segment, 23: Part where the gripping tool abuts, 31: One end face, 32: The other end face, 33: Partial segment, 33a: Partial segment constituting the outer periphery, 33b: Part located in the central part Segment: 34: Notch, 35: Buffer part, 36: Honeycomb structure part, 41: One end face, 42: The other end face, 43: Partial segment, 44: Notch, 45: Buffer part, 46: Outermost part, 54 : Slit, 5 : Outermost peripheral part, 61: slit, 62: outermost peripheral part, 63: opening part, 71: one end face, 72: notch, 73: partial segment, 74: buffer part, 100, 200, 522, 524: honeycomb forming 110, 210, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 521, 523: slit-formed honeycomb molded body, 120, 220, 420: aggregates of partial segments, 130, 240, 300, 320, 330, 340, 430, 430a, 430b, 530: honeycomb structure, 230: buffer portion disposition partial segment.

Claims (10)

Extruding a forming raw material to form a honeycomb formed body having partition walls that partition and form a plurality of cells extending from one end face to the other end face to be a fluid flow path,
In the honeycomb formed body, a plurality of slits are formed in parallel to the cell extending direction to form a slit-formed honeycomb formed body,
Firing the slit-formed honeycomb molded body to form a slit-formed honeycomb fired body,
An assembly of partial segments, in which the slit-formed honeycomb fired body is opened at least on one end face side, and a slit is formed so as to include the slit, and a plurality of partial segments are defined by the slit. Form the
Wherein by filling the partial segment aggregate filler to the notches as before Symbol slit formed in the method for manufacturing a honeycomb structure to obtain a honeycomb structure to form a buffer portion between respective partial segments adjacent to each other.   The method for manufacturing a honeycomb structured body according to claim 1, wherein each of the slits formed before firing forms an opening on the end face and does not form an opening on the outer peripheral face.   The method for manufacturing a honeycomb structured body according to claim 2, wherein each slit formed before firing forms an opening only on one end face.   The method for manufacturing a honeycomb structured body according to claim 3, wherein a part of the plurality of slits opens on the one end face, and the remaining slits open on the other end face.   The method for manufacturing a honeycomb structured body according to claim 2, wherein each of the slits formed before firing forms an opening on both end faces.   The method for manufacturing a honeycomb structure according to claim 1, wherein each of the slits formed before firing forms an opening on an outer peripheral surface and does not form an opening on the end surface.   The method for manufacturing a honeycomb structured body according to claim 6, wherein each slit formed before firing forms one opening on the outer peripheral surface.   The method for manufacturing a honeycomb structure according to claim 6, wherein each slit formed before firing forms two openings on the outer peripheral surface.   The method for manufacturing a honeycomb structured body according to any one of claims 1 to 8, wherein a slit formed in the slit-formed honeycomb fired body is formed so as to open to the other end face side.   The method for manufacturing a honeycomb structured body according to any one of claims 1 to 8, wherein the slit formed in the slit-formed honeycomb fired body is formed so as to open only on the one end face side.

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