JP2011245854A - Method of manufacturing honeycomb structure, and honeycomb structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a honeycomb structure that facilitates achieving the honeycomb structure in which a strength of a whole coat layer is uniform, and a surface strength of a coat layer is high, and to provide the honeycomb structure.SOLUTION: The method of manufacturing the honeycomb structure includes: a fixing step which fixes two or more honeycomb sintered compacts in a form; a filling step which fills up a gap between the form and a honeycomb sintered compact and a gap between honeycomb sintered compacts with a seal material paste; and a drying step which carries out drying solidification of the seal material paste and forms an adhesive material layer and a coat layer, wherein the seal material paste includes an inorganic particle and/or inorganic fiber, the form, an inside surface of the form or a member arranged at an inside surface side of the form has a ventilation part having air permeability prepared, and in the drying step the seal material paste is made to contact with at least part of the ventilation part and drying solidification of the seal material paste is performed.

Description

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

As an exhaust gas purification filter or a catalyst carrier, a honeycomb structure formed by combining a plurality of columnar honeycomb fired bodies in which a large number of cells are arranged in the longitudinal direction is known. The honeycomb structure has a ceramic block made of a honeycomb fired body and a coat layer disposed on the outer periphery thereof. The ceramic block is formed by fixing a plurality of columnar honeycomb fired bodies via an adhesive layer formed on a side surface.

As a method for manufacturing a honeycomb structure, a method of forming an adhesive layer and a coat layer in separate steps is known. In this method, first, a plurality of honeycomb fired bodies are bonded using a sealing material paste, and the sealing material paste is dried and solidified to form an adhesive layer. Thereby, a ceramic block in which the honeycomb fired bodies are firmly bonded to each other is obtained. Next, a sealing material paste is applied around the ceramic block and dried and solidified to form a coat layer, thereby forming a honeycomb structure.

However, in the above method, since the adhesive layer and the coat layer are formed in separate steps, a boundary surface that separates the two is formed between the adhesive layer and the coat layer. When such a honeycomb structure is used as, for example, an exhaust gas purification filter for a vehicle, it is exposed to a rapid temperature rise at the start of operation, or a thermal cycle from vehicle operation to filter regeneration processing is repeated over a long period of time. For example, peeling or breakage occurs at the interface between the adhesive layer and the coat layer.

Therefore, Patent Documents 1 to 3 disclose a method in which the adhesive layer and the coat layer are integrally formed so that there is no boundary surface that separates the two. Specifically, in the methods described in Patent Documents 1 and 2, first, a plurality of honeycomb fired bodies are assembled into a predetermined shape while maintaining a certain interval by using an assembling apparatus, and this shape is assembled using a formwork. Fix it. Next, a sealing material paste is injected between the honeycomb fired body and between the honeycomb fired body and the mold. Then, by drying and solidifying the sealing material paste, the adhesive layer and the coating layer are integrally formed so that there is no boundary surface that separates the two. In Patent Document 3, when assembling a honeycomb fired body into a predetermined shape, the honeycomb fired body is held at a constant interval using a spacing member, and the adhesive layer and the coat layer are integrally formed using a mold. A method of forming is disclosed.

International Publication No. 2008 / 126334A1 Pamphlet International Publication No. 2008 / 139608A1 Pamphlet International Publication No. 2005 / 047210A1 Pamphlet

However, a honeycomb structure in which the adhesive layer and the coat layer are integrally formed so that there is no boundary that separates the two tends to be slightly inferior in the strength of the coat layer itself and the surface strength of the coat layer. Therefore, a honeycomb structure excellent in the strength of the coat layer itself and the surface strength of the coat layer is required.

The present invention has been made in view of the above situation, and a honeycomb structure manufacturing method capable of easily manufacturing a honeycomb structure having a uniform strength of the entire coat layer and a high surface strength of the coat layer, Another object of the present invention is to provide a honeycomb structure in which the strength of the entire coating layer is uniform and the surface strength of the coating layer is high.

The method for manufacturing a honeycomb structured body according to claim 1, wherein a plurality of pillar-shaped honeycomb fired bodies in which a large number of cells are arranged in parallel in the longitudinal direction with a cell wall therebetween are bound together via an adhesive layer. A method for manufacturing a honeycomb structure in which a coating layer is provided around a block, the forming step of extruding a honeycomb formed body having cell walls formed on the outer peripheral portion, and firing the honeycomb formed body by firing the honeycomb formed body A firing step of forming a body, a fixing step of fixing a plurality of honeycomb fired bodies in a mold, and a filling step of filling a gap between the mold and honeycomb fired bodies and a gap between the honeycomb fired bodies with a sealing material paste And a drying step of drying and solidifying the sealing material paste to form the adhesive layer and the coating layer, and the sealing material paste includes inorganic particles and / or inorganic fibers, The inner surface of the mold or the member disposed on the inner surface side of the mold is provided with an air permeable ventilation part, and in the drying step, the sealing material paste is at least included in the ventilation part. The sealing material paste is dried and solidified by contacting a part thereof.

According to the above manufacturing method, when the moisture contained in the sealing material paste becomes water vapor in the drying step, the air containing water vapor is not only discharged to the outside through the pores formed in the honeycomb fired body, but also the ventilation portion. It is discharged to the outside through. That is, the moisture contained in the sealing material paste forming the coating layer moves not only to the honeycomb fired body side but also to the ventilation portion side, so that the movement of moisture that is biased toward the honeycomb fired body side can be mitigated. Occurrence of migration of inorganic fibers and / or inorganic particles contained in the sealing material paste can be suppressed. The obtained coating layer has a uniform strength throughout the coating layer and excellent surface strength of the coating layer.

In the method for manufacturing a honeycomb structured body according to claim 2, the mold is formed of a dense metal, a mold formed of a porous metal, and a plurality of recesses and / or protrusions on an inner surface. One of the molds made of a dense metal with a molded part.
On the inner surface side of the mold formed of a dense metal, a member including a ventilation portion having air permeability is provided.
In the mold formed of a porous metal, the mold itself includes a ventilation portion and has air permeability. In the method for manufacturing a honeycomb structure of the present invention, a member including a ventilation portion having air permeability may be further provided on the inner surface side of a mold formed of a porous metal.
A mold made of a dense metal with a plurality of recesses and / or protrusions formed on the inner surface is not air permeable, but a sealing material paste is injected between the honeycomb fired body and the mold. In this case, if a gap is generated by the concave portion and / or the convex portion, the gap can be used as a ventilation portion. That is, it can be said that the mold made of a dense metal having a plurality of concave portions and / or convex portions formed on the inner surface includes an air permeable portion on the inner surface of the mold frame. In this case, it is good also as a structure which provided the member containing the ventilation part which has air permeability further in the inner surface side of a formwork.

In the method for manufacturing a honeycomb structure according to claim 3, the member disposed on the inner surface side of the mold is at least selected from a paper member, a nonwoven fabric member, a mesh member, a porous resin layer, and a porous carbon layer. It consists of a kind. These may be used alone to form a ventilation part, or a plurality of these may be combined to form a ventilation part.

In the method for manufacturing a honeycomb structured body according to claim 4, the ventilation portion has an average pore diameter of 0.1 μm to 50 μm.
When the ventilation portion has such an average pore diameter, air permeability can be ensured while suppressing the movement of the inorganic particles and / or inorganic fibers contained in the sealing material paste.

In the method for manufacturing a honeycomb structured body according to claim 5, the air permeability of the mold or the member disposed on the inner surface side of the mold is 0.05 cc / cm ² / sec or more.
If the member including the mold or the ventilation portion has such air permeability, migration of inorganic particles and / or inorganic fibers contained in the sealing material paste can be sufficiently eliminated.

In the method for manufacturing a honeycomb structured body according to claim 6, the mold and the member disposed on the inner surface side of the mold include a ventilation portion, the mold is made of a porous metal, and the member Consists of a paper member or a nonwoven fabric member. According to this, air permeability can be imparted by the porous metal and the paper member or the non-woven fabric member, and when the paper structure or the non-woven fabric member and the sealing material paste are in contact with each other, a good separation can be obtained when releasing the honeycomb structure. Type characteristics are obtained. Further, when the air permeability or releasability of the paper member or the nonwoven fabric member is reduced due to the adhesion of the sealing material paste, the paper member or the nonwoven fabric member can be easily replaced.

In the method for manufacturing a honeycomb structured body according to claim 7, the member disposed on the inner surface side of the mold includes a ventilation portion, the member is made of a paper member or a nonwoven fabric member, and the mold is dense. Made of quality metal. According to this, air permeability can be imparted by a paper member or a non-woven member, and good releasability is obtained when the honeycomb structure is released by contacting the paper member or the non-woven member with the sealing material paste. It is done. In addition, when the air permeability and releasability of the paper member or the nonwoven fabric member are reduced due to adhesion of the sealing material paste, the paper member or the nonwoven fabric member can be easily replaced.

In the method for manufacturing a honeycomb structured body according to claim 8, the paper member is a paper member subjected to silicon processing.
In this specification, the paper member that has been subjected to silicon processing is a craft paper or glassine paper surface coated with a silicon resin material, or a kraft paper or glassine paper impregnated with a silicon resin material. Say. Paper members such as kraft paper or glassine paper subjected to silicon processing can be easily peeled off from the dried and solidified sealing material paste.

In the method for manufacturing a honeycomb structured body according to claim 9, an average pore diameter of the ventilation portion provided in the portion subjected to the silicon processing is 20 μm to 50 μm.

In the method for manufacturing a honeycomb structured body according to claim 10, the porous metal or the dense metal constituting the mold is copper, nickel, stainless steel, or an alloy using at least one of these metals. .

In the method for manufacturing a honeycomb structured body according to claim 11, the nonwoven fabric member is a polyester nonwoven fabric member containing polyester fibers.

In the method for manufacturing a honeycomb structured body according to claim 12, the porous resin layer is made of at least one selected from a fluororesin and polypropylene.

In the method for manufacturing a honeycomb structured body according to claim 13, the formwork can be separated into a plurality of members, and in the fixing step, the plurality of members are used in combination.

In the method for manufacturing a honeycomb structured body according to claim 14, in the fixing step, the plurality of honeycomb fired bodies are fixed by further using an interval holding member that holds the honeycomb fired bodies at regular intervals.

In the method for manufacturing a honeycomb structured body according to claim 15, in the fixing step, the honeycomb fired body is fixed by holding both end faces of the honeycomb fired body. According to this, the honeycomb fired body can be easily held in a predetermined shape.

In the method for manufacturing a honeycomb structured body according to claim 16, in the sealing material paste, in the drying step, the presence ratio of the inorganic particles and the presence ratio of the inorganic fibers are respectively the surface side of the coating layer and the coating layer. The sealing material paste is dried and solidified so as to be substantially the same on the ceramic block side of the layer. According to this, the strength is uniform throughout the coat layer, the surface of the coat layer has no unevenness due to uneven dispersion of inorganic particles and / or inorganic fibers, the surface strength is high, and the surface of the coat layer is powdery. No honeycomb structure is obtained.
In the present specification, “the presence ratio of the inorganic particles and the presence ratio of the inorganic fibers are substantially the same on the surface side of the coat layer and the ceramic block side of the coat layer” means the following: I will say.
When the sealing material paste contains only inorganic particles among inorganic particles and inorganic fibers, “the presence ratio of inorganic particles and the existence ratio of inorganic fibers are respectively the surface side of the coat layer and the coat layer. The phrase “substantially the same on the ceramic block side” means that the proportion of inorganic particles present on the surface side of the coat layer is substantially the same as the proportion of inorganic particles present on the ceramic block side of the coat layer. And
Further, when the sealing material paste contains only inorganic fibers among inorganic particles and inorganic fibers, “the presence ratio of the inorganic particles and the existence ratio of the inorganic fibers are respectively the surface side of the coating layer and the coating layer. `` It is substantially the same on the ceramic block side of the layer '' means that the inorganic fiber existing ratio on the surface side of the coat layer and the inorganic fiber existing ratio on the ceramic block side of the coat layer are substantially the same. I will say.
Further, when both the inorganic particles and the inorganic fibers are contained in the sealing material paste, “the presence ratio of the inorganic particles and the existence ratio of the inorganic fibers are respectively the surface side of the coat layer and the ceramic block side of the coat layer. And “substantially the same” means that the proportion of inorganic particles present on the surface side of the coat layer is substantially the same as the proportion of inorganic particles present on the ceramic block side of the coat layer, and the surface of the coat layer. The presence ratio of the inorganic fibers on the side and the presence ratio of the inorganic fibers on the ceramic block side of the coat layer are substantially the same.
The presence ratio of the inorganic particles on the surface side of the coat layer and the presence ratio of the inorganic particles on the ceramic block side of the coat layer are “substantially the same”. It means 80% to 120% of the “abundance ratio of inorganic particles on the ceramic block side of the coat layer”. The “abundance ratio of the inorganic particles on the surface side of the coat layer” is more desirably 90% to 110% of the “abundance ratio of the inorganic particles on the ceramic block side of the coat layer”, and 95% to 105%. Is more desirable, and it is more desirable that it is 99% to 101%.
The presence ratio of the inorganic fibers on the surface side of the coat layer and the presence ratio of the inorganic fibers on the ceramic block side of the coat layer are “substantially the same”. It means 80% to 120% of the “abundance ratio of inorganic fibers on the ceramic block side of the coat layer”. The “abundance ratio of inorganic fibers on the surface side of the coat layer” is more desirably 90% to 110% of “abundance ratio of inorganic fibers on the ceramic block side of the coat layer”, and 95% to 105%. Is more desirable, and it is more desirable that it is 99% to 101%.
In the present specification, “the surface side of the coat layer” refers to a portion of the coat layer that is closer to the surface of the coat layer than to the ceramic block. “The ceramic block side of the coat layer” refers to a portion of the coat layer that is closer to the ceramic block than to the surface of the coat layer.

The honeycomb structure according to claim 17, wherein a plurality of columnar honeycomb fired bodies in which a large number of cells are arranged in parallel in a longitudinal direction with a cell wall therebetween are bound around a ceramic block formed by bonding with an adhesive layer. A honeycomb structure provided with a coating layer, wherein the adhesive layer and the coating layer include inorganic particles and / or inorganic fibers, and the adhesive layer and the coating layer are integrally formed. In addition, there is no boundary that separates the two, and the presence ratio of the inorganic particles and the presence ratio of the inorganic fibers are substantially the same on the surface side of the coat layer and the ceramic block side of the coat layer, respectively. .

In the honeycomb structure having such a configuration, the inorganic particles and / or the inorganic fibers contained in the coat layer are almost uniformly dispersed on the surface side and the ceramic block side. can get. In addition, since the surface of the coat layer is not uneven due to dispersion of inorganic particles and / or inorganic fibers, the honeycomb structure has a high surface strength and is not powdery.

FIG. 1 is a perspective view schematically showing an example of a honeycomb structure according to the first embodiment of the present invention. 2 (a), 2 (b), and 2 (c) are perspective views schematically showing an example of a honeycomb fired body constituting the honeycomb structure according to the first embodiment of the present invention. is there. FIG. 3 is a flowchart for explaining a manufacturing process of the honeycomb structure according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the first embodiment of the present invention. FIG. 5A is a cross-sectional view taken along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing the state of the mold with the supply device attached thereto in the first embodiment of the present invention. Fig. 5 (b) is a cross-sectional view along a direction parallel to the longitudinal direction of the honeycomb fired body, schematically showing the state of the mold frame equipped with the supply device in the first embodiment of the present invention. FIG. 6A is a cross-sectional view taken along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the mold material is filled with the sealing material paste in the first embodiment of the present invention. . Fig. 6 (b) is a cross-sectional view along a direction parallel to the longitudinal direction of the honeycomb fired body, schematically showing a state in which a mold material is filled with a sealing material paste in the first embodiment of the present invention. . Fig.7 (a) is the perspective view which showed typically the state of the formwork in drying process (S5) in 1st embodiment of this invention. FIG. 7B is a longitudinal view of the honeycomb fired body for schematically illustrating the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the drying step (S5) in the first embodiment of the present invention. It is a partial sectional view along a direction perpendicular to the direction. FIG. 8A is a perspective view schematically showing the state of the mold in the drying step (S5) of Comparative Example 1. FIG. FIG. 8 (b) shows a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically showing the movement of moisture contained in the sealing material paste in contact with the inner surface of the mold in the drying step (S5) of Comparative Example 1. FIG. FIG. 9A is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the second embodiment of the present invention. is there. FIG. 9B schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the second embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG. FIG. 10 (a) is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the third embodiment of the present invention. is there. FIG.10 (b) is the perspective view which showed typically the state of the formwork in drying process (S5) in 3rd embodiment of this invention. FIG. 11 (a) shows a third embodiment of the present invention in a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically illustrating the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold. FIG. FIG. 11B schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the fourth embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG. FIG. 11 (c) schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the fifth embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG. FIG. 12 is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold according to the sixth embodiment of the present invention. FIG. 13A is a perspective view schematically showing the state of the mold in the drying step (S5) in the sixth embodiment of the present invention. FIG. 13 (b) shows a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically showing the movement of moisture contained in the sealing material paste in contact with the inner surface of the mold in the sixth embodiment of the present invention. FIG. 14 (a), 14 (b), 14 (c), 14 (d), and 14 (e) illustrate a fixing process of the honeycomb fired body according to the seventh embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a state along the direction perpendicular to the longitudinal direction of the honeycomb fired body with respect to the arrangement of the honeycomb fired body in the mold. FIG. 15 is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is disposed inside the mold according to the eighth embodiment of the present invention. FIG. 16 schematically shows a state in which a honeycomb fired body is arranged inside a mold that can be divided into two mold members in the ninth embodiment of the present invention, perpendicular to the longitudinal direction of the honeycomb fired body. It is sectional drawing which follows an arbitrary direction.

The conventional honeycomb structure in which the adhesive layer and the coat layer are integrally formed so that there is no boundary that separates the two is compared with the conventional honeycomb structure in which the adhesive layer and the coat layer are separately formed. Thus, the strength of the coating layer itself and the surface strength of the coating layer tend to be slightly inferior. The inventors of the present invention have made various studies on the honeycomb structure in which the adhesive layer and the coat layer are integrally formed so that there is no boundary surface that separates the two. It was found that this was caused by the drying treatment of the sealing material paste as a layer.

When manufacturing a honeycomb structure in which an adhesive layer and a coat layer are integrally formed so that there is no boundary between the adhesive layer and a coat layer, the adhesive layer and the coat layer are fired from a plurality of honeycombs assembled in a mold. It is formed by filling a sealing material paste between the bodies and between the honeycomb fired body and the mold and heating and drying the sealing material paste.
The moisture in the sealing material paste filled between the honeycomb fired bodies to form the adhesive layer becomes water vapor by heating to the honeycomb fired body which is a porous body provided on both sides of the sealing material paste. And move. Thereby, the inorganic particles and the inorganic fibers contained in the sealing material paste also move to the side of the honeycomb fired body provided on both sides.
On the other hand, the moisture in the sealing material paste filled between the honeycomb fired body and the mold for forming the coat layer can be moved to the honeycomb fired body when it becomes water vapor by heating. Cannot move to the side. In the conventional method for manufacturing a honeycomb structure in which the adhesive layer and the coat layer are integrally formed so that there is no boundary that separates the two, the dense layer formed of a dense metal as a mold is used. This is because a solid metal mold or a mold having a fluororesin layer formed on the inner surface side of the dense metal mold for the purpose of improving the releasability of the honeycomb structure is used.

Since the above-described conventional mold has no air permeability and cannot transmit air containing water vapor generated by heating, the moisture in the sealing material paste as a coating layer is inevitably on the side of the mold. To the honeycomb fired body side. As the moisture moves, inorganic fibers or inorganic particles contained in the sealing material paste move from the mold side to the honeycomb fired body side. Thereby, dispersion unevenness occurs in the inorganic particles and the inorganic fibers in the sealing material paste, and so-called migration occurs in which the inorganic particles and the inorganic fibers are unevenly present.
When migration occurs, since the inorganic particles and the inorganic fibers are not uniformly dispersed on the surface side and the ceramic block side in the obtained coating layer, the overall strength of the coating layer varies. In addition, fine irregularities are generated on the surface of the coating layer due to uneven dispersion of inorganic particles and inorganic fibers, which makes the surface of the coating layer easy to scrape or peel off, and the surface of the coating layer is in a powdery state. Become. When the coat layer is in such a state, when the honeycomb structure is used as an exhaust gas purification filter or a catalyst carrier, cracks due to expansion and contraction of the honeycomb structure when exposed to a high temperature such as a regeneration treatment are obtained. It is thought that it will lead to outbreak.

In consideration of the above phenomenon, the present inventors move inorganic particles and inorganic fibers of the coating layer by moving moisture in the sealing material paste that moves toward the honeycomb fired body to the mold side. It was thought that it could be uniformly dispersed on the surface. Therefore, when the mold and / or the inner surface side of the mold (including the inner surface of the mold) is configured to have air permeability that allows air containing water vapor to pass therethrough, It has been found that moisture can be moved not only to the honeycomb fired body side but also to the mold side, and the present invention has been achieved.

In the above description, the case where the sealing material paste includes inorganic fibers and inorganic particles has been described. However, the reason why migration occurs is the same when only one of the inorganic fibers and the inorganic particles is included.
In order to suppress the occurrence of migration, it is conceivable to dry and solidify the sealing material paste after removing the mold, but if the mold is removed while the sealing material paste is uncured, the surface of the sealing material paste This is undesirable because the surface of the resulting coating layer is uneven, resulting in depressions or deformations.

In the present invention, air permeability refers to a property that allows air containing moisture (water vapor) contained in a sealing material paste forming a coating layer to pass therethrough.
Air permeability (also referred to as air permeability) is measured according to the measurement method described in JIS L1096 (Method A). The ventilation part in the present invention is not particularly limited as long as it can transmit air containing moisture (water vapor), and the air permeability is 0.05 cc / cm ² / sec or more. desirable. The upper limit of the air permeability is not necessary to particularly specify, the air permeability ^is more preferably in the range of ^{0.05cc / cm 2 / sec~100cc / cm} 2 / sec, 1cc / cm 2 / sec~100cc / more desirably ^cm in the range of 2 / ^sec, and particularly preferably in the range of ^{5cc / cm 2 / sec~100cc / cm} 2 / sec. However, even if the air permeability exceeds 100 cc / cm ² / sec, the effect is not impaired.
The ventilation portion having air permeability refers to a portion through which air containing moisture (water vapor) contained in the sealing material paste forming the coating layer can be transmitted. "The mold, the inner surface of the mold, or the member disposed on the inner surface side of the mold is provided with an air permeable ventilation part" means that the mold itself has air permeability. The mold itself has air permeability, and another member having air permeability is further disposed on the inner surface side of the mold, and the mold itself is not air permeable. The sealing material paste is formed by disposing another member having air permeability on the inner surface side of the sheet, and having no air permeability in the mold itself, but having recesses and / or protrusions formed on the inner surface. This means that a gap having air permeability is formed when the gas is injected.
The inner surface of the mold frame is the surface of the mold frame on the honeycomb fired body side, and the member is disposed on the inner surface side of the mold frame means that the air permeable member is integrally or separable on the inner surface side of the mold frame. Means that is placed.

As a ventilation part, the thing of the following aspects is mentioned, for example.

As the first aspect of the present invention, there is an aspect in which the mold itself does not have air permeability, but another member having air permeability is further arranged on the inner surface side of the mold.
As an example of such an embodiment, there is an example in which the mold is formed of a dense metal, and another member having air permeability is provided on the inner surface side of the mold. The member provided on the inner surface side of the formwork may be formed integrally with the formwork or may be configured to be separable.
In the first aspect of the present invention, as an example in which the mold and the member disposed on the inner surface side of the mold are formed to be separable, the mold is formed of a dense metal, and a paper is formed on the inner surface thereof. What arranged the member or the nonwoven fabric member is mentioned.
In the first aspect of the present invention, as an example in which the mold and the member disposed on the inner surface side of the mold are integrally formed, the mold is formed of a dense metal and porous on the inner surface. In which a porous resin layer, a porous carbon layer and the like are formed.

As a 2nd aspect of this invention, the form itself (the whole formwork) has air permeability, and the aspect by which another member was provided in the inner surface side of this formwork is mentioned. That is, the mold is an air permeable mold formed of a porous metal, and an air permeable member is further provided on the inner surface side of the mold. The member disposed on the inner surface side of the mold frame may be formed integrally with the mold frame or may be configured to be separable.
In the second aspect of the present invention, as an example in which the mold and the member disposed on the inner surface side of the mold are formed so as to be separable, the mold is formed of a porous metal and paper What arranged any of a member, a nonwoven fabric member, and a mesh member (for example, stainless steel mesh) is mentioned.
In the second aspect of the present invention, as an example in which the mold and the member disposed on the inner surface side of the mold are integrally formed, the mold is formed of a porous metal and porous on the inner surface. In which a porous resin layer or a porous carbon layer is formed.

As a 3rd aspect of this invention, the formwork itself (the whole formwork) has air permeability, and the form itself contains a ventilation part is mentioned. An example of such an embodiment is one in which the mold is formed of a porous metal.

Both the second and third aspects of the present invention can be suitably used because the mold itself has air permeability, but the coat layer can be peeled off (releasability of the honeycomb structure). In view of the above, the second aspect of the present invention is desirable. Among the second aspects of the present invention, the aspect in which the mold and the member disposed on the inner surface side of the mold are separable is caused by the adhesion of the sealing material paste forming the coat layer, etc. This is desirable from the viewpoint of workability because the member can be easily replaced when the air permeability of the member arranged on the inner surface side of the member decreases.

In the first aspect and the second aspect of the present invention, the thickness of the member disposed on the inner surface side of the mold is desirably 1/10 to 3/4 of the thickness of the mold, More desirably, it is 5 to 1/2. The thickness of the member is appropriately set according to the material of the mold or the porosity of the member, taking into account the required air permeability or the strength of the mold.

In the present invention, a mold formed of a porous metal (hereinafter also referred to as a porous metal mold) is air permeable and uses copper, nickel, stainless steel or an alloy made of at least one of these. The form formed in
In the present invention, a mold formed of a dense metal (hereinafter also referred to as a dense metal mold) is an air-permeable, copper, nickel, stainless steel or an alloy using at least one of these. A formwork formed by In particular, the mold formed of porous metal or dense metal is preferably a mold formed of stainless steel.

In the porous metal mold and the dense metal mold, a fluororesin layer or the like may be formed on the inner surface in consideration of the peelability of the coat layer (the releasability of the honeycomb structure).

The honeycomb structure obtained by the method of integrally forming the adhesive layer and the coat layer using the ventilation portion as described above has a boundary surface that divides both between the adhesive layer and the coat layer. Therefore, even if it is used as an exhaust gas purification filter for vehicles, not only does the peeling between the adhesive layer and the coating layer hardly occur, but the strength of the coating layer is uniform throughout. The layer is less prone to cracking and has excellent durability.

Hereinafter, a method for manufacturing a honeycomb structure according to the present invention will be described in detail, in which an adhesive layer and a coat layer are integrally formed using a ventilation portion so that there is no boundary surface separating the two. Further, the honeycomb structure according to the present invention in which the occurrence of migration is suppressed and the inorganic fibers and the inorganic particles are uniformly dispersed in the coat layer will be specifically described.

(First embodiment)
Hereinafter, a first embodiment which is an embodiment of the present invention will be described.
In this embodiment, the adhesive layer and the coat layer are integrally formed using a member including a ventilation portion disposed on the inner surface side of the dense metal mold so that there is no boundary surface that separates both of them. A method for manufacturing a honeycomb structure will be described.
FIG. 1 is a perspective view schematically showing an example of a honeycomb structure according to the first embodiment of the present invention.
In FIG. 1, the honeycomb structure 100 includes a cylindrical ceramic block 101 and a coat layer 102 provided around the ceramic block 101. The ceramic block 101 is formed by binding a plurality of columnar honeycomb fired bodies 110 with an adhesive layer 103 interposed therebetween.

The columnar honeycomb fired body 110 is made of a porous ceramic. Here, as the honeycomb fired body 110, three types of honeycomb fired bodies 111, 112, and 113 having different cross-sectional shapes when viewed in a cross section perpendicular to the longitudinal direction are used. The details of the honeycomb fired bodies 111, 112, and 113 will be described below with reference to FIGS. 2 (a), 2 (b), and 2 (c).

2 (a), 2 (b), and 2 (c) schematically show an example of a honeycomb fired body constituting the honeycomb structure according to the first embodiment of the present invention shown in FIG. It is the shown perspective view. 2 (a), 2 (b), and 2 (c), the direction parallel to the cell indicated by the double-headed arrow A is referred to as the longitudinal direction, the surface from which the cell is exposed is referred to as the end surface, and other than the end surface. Is called the side.

The side surface of the honeycomb fired body 111 shown in FIG. 2A is composed of two planes and one curved surface. The honeycomb fired body 111 has a configuration in which a large number of cells 111a are juxtaposed in the longitudinal direction (the direction of a double-headed arrow A) with a cell wall 111b interposed therebetween. In the honeycomb fired body 111, either one end of the cell 111a is sealed with a sealing material 111c.
The side surface of the honeycomb fired body 112 shown in FIG. 2B is composed of three planes and one curved surface. Similarly to the honeycomb fired body 111, the honeycomb fired body 112 has a configuration in which a large number of cells 112a are arranged in parallel in the longitudinal direction (direction of a double arrow A) with the cell wall 112b interposed therebetween. Further, in the honeycomb fired body 112, either one end of the cell 112a is sealed with a sealing material 112c.
Furthermore, the side surface of the honeycomb fired body 113 shown in FIG. 2C is constituted by four planes. Similarly to the honeycomb fired body 111, the honeycomb fired body 113 has a configuration in which a large number of cells 113a are arranged in parallel in the longitudinal direction (direction of a double arrow A) with a cell wall 113b interposed therebetween. Further, in the honeycomb fired body 113, either one end of the cell 113a is sealed with a sealing material 113c.

As described above, the honeycomb structure 100 using the honeycomb fired bodies 111, 112, and 113 in which any one end portion of the cells 111a, 112a, and 113a is sealed with the sealing materials 111c, 112c, and 113c is an exhaust gas. It can be used as a honeycomb filter for purification. For example, the exhaust gas that has flowed into the cell 111a always flows out of the other cell 111a after passing through the cell wall 111b. When the exhaust gas passes through the cell wall 111b, the particulates contained in the exhaust gas are captured by the cell wall 111b. Thereby, exhaust gas can be purified. The same applies to the other cells 112a and 113a.
A plurality of the honeycomb fired bodies 111, 112, and 113 described above are bundled through the adhesive layer 103 to form a cylindrical ceramic block 101.

Here, in the honeycomb structure 100 according to the first embodiment of the present invention shown in FIG. 1, the adhesive layer 103 and the coat layer 102 are integrally formed of the same sealing material paste, and the two are divided. There is no boundary surface. When the honeycomb structure 100 having such a configuration is used as a filter for exhaust gas purification, peeling or cracking or the like occurs between the adhesive layer 103 and the coat layer 102 even when used in a high temperature atmosphere. Disappears.

The adhesive layer 103 and the coat layer 102 include inorganic fibers and inorganic particles. The adhesive layer 103 and the coat layer 102 may include either one of inorganic fibers or inorganic particles, but it is desirable from the viewpoint of strength to include both inorganic fibers and inorganic particles.
In the honeycomb structure 100 according to the first embodiment of the present invention, the presence ratio of the inorganic fibers on the surface side of the coat layer 102 and the presence ratio of the inorganic fibers on the ceramic block 101 side of the coat layer 102 are substantially the same. In addition, the existence ratio of the inorganic particles on the surface side of the coat layer 102 and the existence ratio of the inorganic particles on the ceramic block 101 side of the coat layer 102 are substantially the same. In the honeycomb structure 100 having such a configuration, the strength of the coat layer 102 itself is uniform, the surface strength of the coat layer 102 is high, and there is no powderiness.

Examples of the inorganic particles contained in the adhesive layer 103 and the coat layer 102 include inorganic powder made of carbide such as silicon carbide, nitride such as silicon nitride or boron nitride, and the like. Among these, a powder made of silicon carbide is preferable because of its excellent thermal conductivity. These may be used alone or in combination of two or more.
The average particle size of the inorganic particles is desirably 0.1 μm to 50 μm, and more desirably 0.1 μm to 1.0 μm.
Examples of inorganic fibers contained in the adhesive layer 103 and the coat layer 102 include ceramic fibers such as silica-alumina, mullite, alumina, and silica. Among these, inorganic fibers made of alumina are desirable. These may be used alone or in combination of two or more.
The average fiber diameter of the inorganic fibers is preferably in the range of 1 μm to 50 μm, and more preferably in the range of 5 μm to 40 μm. The average fiber length of the inorganic fibers is desirably in the range of 10 μm to 200 μm, and more desirably in the range of 20 μm to 100 μm.

Below, the manufacturing method of the honeycomb structure 100 which concerns on 1st embodiment of this invention comprised as mentioned above is demonstrated.
FIG. 3 is a flowchart for explaining a manufacturing process of the honeycomb structure according to the first embodiment of the present invention.
As shown in FIG. 3, the manufacturing process of the honeycomb structure 100 according to the first embodiment of the present invention includes a forming process for forming a honeycomb formed body (step S1), and firing the honeycomb formed body to form a honeycomb fired body. Firing step (step S2), fixing step (step S3) for placing and fixing the honeycomb fired body in the mold, filling step (step S4) for filling the mold with the sealing material paste, and the filled seal A drying step (step S5) for drying and solidifying the material paste is provided. Through these steps, the cylindrical honeycomb structure 100 shown in FIG. 1 can be manufactured without performing post-processing such as cutting.

Details of each step will be described below.
First, in the forming step (S1), a honeycomb formed body is manufactured. The shape of the honeycomb formed body is not particularly limited as long as it is a columnar shape, but in this embodiment, in order to manufacture the columnar honeycomb structure 100 shown in FIG. 1, FIGS. Since the three types of honeycomb fired bodies 111, 112, and 113 shown in FIG. 2B and FIG. 2C are manufactured, 3 having substantially the same shape as these honeycomb fired bodies in consideration of heat shrinkage and the like. Various types of honeycomb molded bodies are produced. The honeycomb formed body is manufactured by extrusion molding using a raw material composition containing ceramic powder and a binder.

For the raw material composition, for example, a wet mixture prepared as follows, that is, a silicon carbide powder having a different average particle diameter is used as a ceramic powder, an organic binder is used as a binder, a silicon carbide powder, an organic binder, a liquid A wet mixture in which a plasticizer, a lubricant, and water are mixed can be applied.

The ceramic powder is not particularly limited. For example, 100 parts by weight of silicon carbide powder having an average particle diameter of 1.0 μm to 50 μm and silicon carbide powder 5 having an average particle diameter of 0.1 μm to 1.0 μm. What combined the weight part-65 weight part is mentioned.

The wet mixture as the raw material composition prepared as described above is formed into a honeycomb formed body of various shapes by extrusion using an extruder. The extruded honeycomb formed body is dried using a dryer.
For the drying process, a microwave dryer, a hot air dryer, a dielectric dryer, a vacuum dryer, a vacuum dryer, a freeze dryer, or the like can be used.
The dried honeycomb formed body is cut into a desired length using a cutting device.
Then, a predetermined amount of a sealing material paste is filled into one of the end portions of the cell to seal the cell. When sealing the cells, for example, a method of applying a sealing mask to the end face (cut cut surface) of the honeycomb molded body and filling the sealing material paste only into the cells that need to be sealed can be used. it can.
The plugged honeycomb formed body is heated and degreased in a degreasing furnace. The degreasing conditions are not particularly limited, and are appropriately selected depending on the type and amount of organic matter contained in the honeycomb formed body. For example, a degreasing treatment of about 2 hours at a temperature of about 400 ° C. can be mentioned.

Next, in the firing step (S2), the honeycomb formed body produced in the forming step (S1) is fired in a firing furnace to produce three types of honeycomb fired bodies 111, 112, and 113.
The firing conditions are not particularly limited, but the firing temperature is desirably in the range of 2000 ° C to 2200 ° C.
As a result, as shown in FIGS. 2A, 2B, and 2C, a large number of cells 111a, 112a, and 113a are arranged in the longitudinal direction across the cell walls 111b, 112b, and 113b. Columnar honeycomb fired bodies 111, 112, and 113 having various shapes arranged side by side are obtained.
Note that the pore diameters and the like of the honeycomb fired bodies 111, 112, and 113 can be set to desired values by adjusting the particle diameter of the ceramic powder contained in the raw material composition.

Next, in the fixing step (S3), the obtained three types of honeycomb fired bodies 111, 112, and 113 are assembled so as to have a columnar shape, and are arranged and fixed in a mold (tubular jig). Specifically, the bottom and top surfaces of the cylindrical jig are covered so that the sealing material paste does not leak from the mold even when the sealing material paste is filled. Further, a lid may be provided on the upper surface or the bottom surface of the jig composed of the cylindrical jig and the plate material on the bottom surface or the upper surface.
FIG. 4 is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the first embodiment of the present invention.

In FIG. 4, a mold 411 is a dense metal mold without air permeability.
The mold 411 is formed of copper, nickel, stainless steel, or an alloy using at least one of these metals. Therefore, it has sufficient strength to fix the honeycomb fired body.
The mold 411 has a cylindrical shape in which a space for arranging the honeycomb fired body 110 (111, 112, 113) is formed.
It is desirable that the inner surface of the mold 411 is coated with a fluororesin or the like for the purpose of improving releasability.

On the inner surface 411a side of the mold 411, a member including a ventilation portion is provided.
The member including the ventilation portion is provided to suppress migration of inorganic fibers or inorganic particles on the surface of the coat layer as described above. Therefore, it is desirable that the member including the ventilation portion is provided on the entire surface in contact with the sealing material paste serving as the coat layer. By having such a member on the inner surface side of the mold, it is possible to suppress the migration of inorganic fibers and inorganic particles contained in the sealing material paste in the drying step (S5) described later.

In the present embodiment, the member is made of paper 412 (also referred to as a paper member). The paper 412 is not particularly limited as long as it has air permeability, but the air permeability (air permeability) measured by JIS L 1096 (Method A) is 0.05 cc / cm ² / sec or more. it is desirable that there ^is more preferably in the range of ^{0.05cc / cm 2 / sec~100cc / cm} 2 / sec, more preferably in the range of ^{1cc / cm 2 / sec~100cc / cm} 2 / sec it is particularly preferably in the range of ^{5cc / cm 2 / sec~100cc / cm} 2 / sec.
Further, considering that the paper 412 is disposed on the inner surface side of the formwork 411, the workability is good and the paper 412 can be suitably used. Therefore, the thickness is preferably 0.06 mm to 0.12 mm, and preferably 0.08 mm to 0.08 mm. More preferably, it is 0.10 mm.
The paper 412 preferably has an average pore diameter of 0.1 μm to 50 μm, and more preferably 0.1 μm to 5 μm.

In consideration of the releasability of the honeycomb structure after the drying step (S5), which will be described later, it is desirable that the surface of the paper member be coated.
Examples of the paper subjected to the coating treatment include craft paper or glassine paper subjected to silicon processing. Kraft paper or glassine paper subjected to silicon processing is one obtained by coating the surface of kraft paper or glassine paper with a silicon resin material, or kraft paper or glassine paper impregnated with a silicon resin material. In the present specification, paper having a release layer containing silicon formed on the surface of kraft paper or glassine paper can be suitably used. Since the paper subjected to the coating treatment or the like has good releasability, it is possible to improve the releasability of the honeycomb structure at the time of release.

The paper member subjected to silicon processing has a main body portion and a silicon coat portion.
The main body portion is a portion where a paper base is present, and the silicon coat portion is a portion where a coated silicon resin material is present.
The method for the coating treatment is not particularly limited, and for example, a conventionally known method such as an air knife, a roll coater, a bar coater, a comma coater, or a blade coater can be used.

The main body portion has a ventilation portion, and the silicon coat portion also has a ventilation portion. The ventilation portion refers to a portion (hole) through which air containing moisture (water vapor) contained in the sealing material paste forming the coating layer can permeate.
The ventilation part that the main body part has is a hole (pore) that exists in the main body part, and the ventilation part that the silicon coat part has is a hole (pore) that exists in the silicon coat part.

The average pore diameter of the ventilation part of the main body part is desirably 0.1 to 50 μm, more desirably 1 to 50 μm, and further desirably 1 to 30 μm. When the average pore diameter of the ventilation portion of the main body is less than 0.1 μm, it is difficult to ensure air permeability.
The ventilation part of the silicon coat part (part subjected to silicon processing) desirably has an average pore diameter of 20 to 50 μm, and more desirably has an average pore diameter of 30 to 40 μm.
The pore diameter refers to the maximum length when a straight line is drawn in the pore (vent). The pores can be observed by obtaining an SEM photograph of a cross section obtained by cutting the paper along the thickness direction. Of the pores in the SEM photograph, the average pore diameter is determined by measuring the maximum length for pores of an appropriate size.

The paper 412 is detachably attached to the mold 411. Examples of a method of attaching the paper 412 to the inner surface 411a side of the mold 411 include a method of sticking the paper 412 to the inner surface 411a of the mold 411 using a double-sided tape.
As described above, when the paper 412 is detachably attached to the mold 411, the paper can be easily attached to the inner surface of the mold 411, and the honeycomb structure 100 is released from the mold. It is possible to easily replace or discard the paper after the operation. Therefore, for example, when the paper 412 becomes dirty due to adhesion of a sealing material paste or the like, the next honeycomb structure 100 can be easily manufactured by simply replacing the paper 412 without cleaning the mold 411. it can.

Note that the paper may be discarded or reused after the honeycomb structure is released through a drying step (S5) described later.

In FIG. 4, a plurality of honeycomb fired bodies 110 (111, 112, 113) are assembled through a spacer 405 inside a mold 411 provided with paper 412 on the inner surface 411 a side so as to be cylindrical. Yes.
The thickness d1 of the spacer 405 is substantially the same as the thickness of the adhesive layer 103 to be formed in a subsequent process, and is substantially the same as the distance d2 of the gap 210 between the side surfaces of the assembled honeycomb fired body 110.
The gap d3 of the gap 220 between the honeycomb fired body 110 assembled in a cylindrical shape and the paper 412 is substantially the same as the thickness of the coat layer 102 formed in a subsequent process.
The material of the spacer 405 is not particularly limited, and examples thereof include those made of cardboard, fiber paper, non-woven fabric, or inorganic filled paper. Note that the cardboard, fiber paper, non-woven fabric, or inorganic filled paper is also referred to as a cardboard member, fiber paper member, non-woven fabric member, inorganic filled paper member, or the like.

Next, in the filling step (S <b> 4), the sealing material paste is filled into the gap 210 between the side surfaces of the honeycomb fired body 110 and the gap 220 between the paper 412 and the side surface of the honeycomb fired body 110. The method for filling the sealing material paste is not particularly limited, but in the present embodiment, an example in which the sealing material paste supply device is attached to the mold 411 will be described.

FIG. 5A is a cross-sectional view taken along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing the state of the mold with the supply device attached thereto in the first embodiment of the present invention. Fig. 5 (b) is a cross-sectional view along a direction parallel to the longitudinal direction of the honeycomb fired body, schematically showing the state of the mold frame equipped with the supply device in the first embodiment of the present invention.
As shown in FIGS. 5A and 5B, the mold 411 is equipped with a supply device 500 for filling a sealant paste. The supply device 500 includes a paste chamber 510 for containing the sealing material paste, and an extrusion mechanism 520 for extruding the sealing material paste from the paste chamber 510 into the mold 411.
In the mold 411, a sealing material paste injection port 401 is formed at a connection portion with the supply device 500, and the sealing material paste is filled through the injection port 401. Further, a plurality of openings 470 are formed in the mold frame 411 on both end face sides of the honeycomb fired body 110.

FIG. 6A is a cross-sectional view taken along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the mold material is filled with the sealing material paste in the first embodiment of the present invention. . Fig. 6 (b) is a cross-sectional view along a direction parallel to the longitudinal direction of the honeycomb fired body, schematically showing a state in which a mold material is filled with a sealing material paste in the first embodiment of the present invention. .
The sealing material paste is supplied to the paste chamber 510 of the supply device 500 shown in FIGS. 5A and 5B, and as shown in FIGS. 6A and 6B, the sealing material paste 600 is supplied. Is pushed in the direction of arrow B by the extrusion mechanism 520, and is supplied from the paste chamber 510 into the mold 411 through the injection port 401. As a result, the sealing material paste 600 is filled in the gap 220 between the paper 412 and the honeycomb fired body 110 arranged on the inner surface 411a side of the mold 411 and the gap 210 between the honeycomb fired bodies 110.
Hereinafter, the sealing material paste 600 serving as a coating layer filled in the gap 220 between the paper 412 and the honeycomb fired body 110 is also referred to as a sealing material paste 600a. In addition, the sealing material paste 600 that is filled in the gap 210 between the honeycomb fired bodies 110 and serves as an adhesive layer is also referred to as a sealing material paste 600b.

In the first embodiment of the present invention, the sealing material paste 600 includes the above-described inorganic particles and inorganic fibers. The sealing material paste 600 containing inorganic particles and inorganic fibers has a reduced viscosity by containing a large amount of moisture in the sealing material paste 600. Thereby, the fluidity of the sealing material paste 600 is increased, and the gap 210 between the honeycomb fired bodies 110 and the gap 220 between the honeycomb fired body 110 and the inner surface 411a of the mold 411 can be satisfactorily filled. it can.

Examples of the moisture contained in the sealing material paste 600 include those derived from an organic binder. Examples of the organic binder include polyvinyl alcohol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and the like. These may be used alone or in combination of two or more. Among organic binders, carboxymethylcellulose is desirable.

In the subsequent drying step (S5), the mold 411 filled with the sealing material paste 600 is heated. Although drying conditions are not specifically limited, For example, it heats for about 1 hour at the temperature of 100 to 150 degreeC. As a result, the sealing material paste 600 a is solidified to become the coat layer 102, and the sealing material paste 600 b is solidified to become the adhesive layer 103.
Here, the sealing material paste 600 a is heated in a state where the sealing material paste 600 a is in contact with the paper 412. By adopting such a configuration, the migration of inorganic fibers or the like contained in the sealing material paste 600 is suppressed, and the coating layer 102 formed by solidifying the sealing material paste 600a has an inorganic particle existing ratio on the surface side, The abundance ratio of the inorganic particles on the ceramic block side is substantially the same, and the abundance ratio of the inorganic fibers on the surface side is substantially the same as the abundance ratio of the inorganic fibers on the ceramic block side. The reason for this will be described below with reference to FIGS. 7 (a) and 7 (b).

Fig.7 (a) is the perspective view which showed typically the state of the formwork in drying process (S5) in 1st embodiment of this invention. FIG. 7B is a longitudinal view of the honeycomb fired body for schematically illustrating the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the drying step (S5) in the first embodiment of the present invention. It is a partial sectional view along a direction perpendicular to the direction. In FIG. 7B, paper 412 is disposed on the inner surface 411 a side of the mold 411.
In FIG. 7A, an arrow P indicates the movement direction of moisture contained in the sealing material paste 600 (600a, 600b), and an arrow S indicates the movement direction of moisture contained in the sealing material paste 600a.
In FIG.7 (b), the arrow Q and the arrow R show the moving direction of the water | moisture content contained in the sealing material paste 600a. Further, in FIG. 7B, the moisture 710 contained in the sealing material paste 600a is schematically shown as a black circle. The portion with a large number of black circles has a large amount of moisture, and the portion with a small amount has a small amount of moisture. It shows that.

When the sealing material paste 600 is heated in the drying step (S5), the moisture contained in the sealing material paste 600 becomes water vapor.
When the moisture contained in the sealing material paste 600b filled between the gaps 210 between the honeycomb fired bodies 110 becomes water vapor, the moisture moves to the honeycomb fired body 110 side. Then, air containing water vapor passes through the honeycomb fired body 110 which is a porous body, and is discharged from the end face of the honeycomb fired body 110 to the outside as indicated by an arrow P in FIG. Although not shown here, as shown in FIG. 6B, the mold 411 has an opening 470 for discharging air containing water vapor to the outside on the end face side of the honeycomb fired body 110. Is formed.
On the other hand, regarding the moisture contained in the sealing material paste 600a filled in the gap 220 between the paper 412 disposed on the inner surface 411a side of the mold 411 and the honeycomb fired body 110, as shown in FIG. Moisture 710 that has become water vapor moves toward the paper 412 side and the honeycomb fired body 110 side. The water vapor 710a that has moved to the honeycomb fired body 110 side passes through the honeycomb fired body 110 as indicated by an arrow R, and from the end face of the honeycomb fired body 110 to the outside as indicated by an arrow P in FIG. Released.
The water vapor 710b that has moved to the paper 412 side is held by the paper 412, or is released from the end surface of the paper 412 to the outside together with the air containing the water vapor 710b, as indicated by the arrow S in FIG. .

Here, the sealing material paste 600 a contains not only moisture 710 but also inorganic fibers 720 and inorganic particles 730.
As described above, when the moisture 710 contained in the sealing material paste 600a becomes the water vapor 710a and moves toward the honeycomb fired body 110 as shown by the arrow R, the inorganic fibers 720 and a part of the inorganic particles 730 are accompanied accordingly. Moves to the honeycomb fired body 110 side.
Further, when the moisture 710 contained in the sealing material paste 600a becomes the water vapor 710b and moves to the paper 412 side indicated by the arrow Q, a part of the inorganic fibers 720 and the inorganic particles 730 are also associated with the mold 411 side. Move to.
Thus, in the present embodiment, the moisture 710 in the sealing material paste 600a moves not only to the honeycomb fired body 110 side but also to the paper 412 side, so that the inorganic fibers 720 contained in the sealing material paste 600a. And the so-called migration in which the inorganic particles 730 are biased toward the honeycomb fired body 110 can be alleviated.
In addition, since the inorganic fibers 720 and the inorganic particles 730 included in the sealing material paste 600a are easily dispersed evenly on the paper 412 side, uniform strength can be obtained over the entire coating layer obtained after release. At the same time, the surface of the coat layer can be smoothed.

Note that the inorganic fibers 720 and the inorganic particles 730 included in the sealing material paste 600a are desirably dispersed uniformly, but only one of the inorganic fibers 720 and the inorganic particles 730 is biased toward the honeycomb fired body. Also by suppressing, the strength in the coat layer can be made uniform, and the surface smoothness of the coat layer can be improved.

Further, when the average pore diameter of the ventilation portion provided in the paper member is smaller than the average particle diameter of the inorganic particles contained in the sealing material paste 600a, the inorganic particles containing the water vapor 710b move along with the inorganic particles. The particles can be prevented from jumping out to the surface of the coat layer, and a coat layer having a smoother surface can be obtained.

When the paper 412 is fixed to the mold 411 using the double-sided tape, an adhesive layer of the double-sided tape for fixing the paper 412 may exist on the inner surface side of the mold 411. This adhesive layer Since it melts and volatilizes when heated at a temperature of 100 ° C. to 150 ° C. as described above, the air permeability of the paper is not impaired. However, in consideration of the air permeability of the paper 412, it is desirable that the double-sided tape for fixing the paper 412 to the mold 411 is provided in as few ranges as possible.

When the drying step is finished, the honeycomb structure 100 is released and the paper 412 is peeled off. Thereby, the honeycomb structure 100 in which the inorganic fibers 720 and the inorganic particles 730 are uniformly dispersed on the surface side of the coat layer 102 is obtained. In the honeycomb structure 100, the strength of the coat layer 102 is uniform throughout, and the surface of the coat layer 102 is excellent in surface strength without dusting.
In addition, since the honeycomb structure 100 is formed integrally so that the adhesive layer 103 and the coat layer 102 do not have a boundary surface that separates them, a thermal cycle such as a regeneration process is performed for a long period of time. Even when it is repeated over the course, breakage (peeling or cracking) between the adhesive layer 103 and the coat layer 102 can be prevented.
Due to the above characteristics, the honeycomb structure 100 according to the first embodiment of the present invention can be suitably used as an exhaust gas purification filter.

In the above description, only the sealing material paste is dried in the drying step (S5). However, after the drying step, degreasing treatment and baking treatment at a higher temperature than the drying treatment may be further performed.

Hereinafter, the manufacturing method of the honeycomb structure of the present embodiment and the effects of the honeycomb structure will be listed.
(1) A method for manufacturing a honeycomb structure according to the present embodiment includes a forming step of extruding a honeycomb formed body having cell walls formed on the outer periphery, and a firing step of forming the honeycomb fired body by firing the honeycomb formed body. A fixing step of fixing a plurality of honeycomb fired bodies in the mold, a filling step of filling a gap between the mold and the honeycomb fired bodies and a gap between the honeycomb fired bodies, and a drying of the sealant paste A drying step of solidifying to form an adhesive layer and a coat layer, and a member disposed on the mold frame, the inner surface of the mold frame, or the inner surface side of the mold frame is provided with a ventilation portion having air permeability In the drying step, the sealing material paste is brought into contact with the ventilation portion to dry and solidify the sealing material paste.

In such a manufacturing method of a honeycomb structure, in the drying process, the moisture contained in the sealing material paste is not only discharged to the outside through the pores formed in the honeycomb fired body as water vapor, It moves to the side of the member provided on the inner surface side of the mold. Thus, the moisture contained in the sealing material paste moves toward the side of the member provided on the inner surface side of the mold and the side of the honeycomb fired body, so that the inorganic fibers and the inorganic particles contained in the sealing material paste The occurrence of migration can be suppressed. This makes it possible to easily manufacture a honeycomb structure in which the strength of the entire coat layer is uniform and the surface strength of the coat layer is excellent.

(2) In the method for manufacturing a honeycomb structure according to the first embodiment of the present invention, the mold itself does not have air permeability, but the member disposed on the inner surface side of the mold is made of a paper member. The paper member can impart air permeability.

(3) Further, in the fixing step in the method for manufacturing a honeycomb structure according to the first embodiment of the present invention, a plurality of honeycomb fired bodies are fixed by further using an interval holding member that holds the honeycomb fired bodies at regular intervals. To do.

When such fixing is performed, since the adhesive paste is injected into the space between the positioned honeycomb fired bodies in the filling step, the thickness of the adhesive paste is substantially the same as the width of the space between the honeycomb fired bodies. . Therefore, the thickness variation of the adhesive paste can be reduced, and a honeycomb structure with high dimensional accuracy can be manufactured.
In addition, since the honeycomb fired body is positioned at a predetermined position before the adhesive paste filling step, even if the position of one honeycomb fired body is shifted, the position of the other honeycomb fired body is not shifted. Not affected. Therefore, a honeycomb structure with high dimensional accuracy can be manufactured as the whole honeycomb structure.

(4) In the honeycomb structure according to the first embodiment of the present invention, a plurality of columnar honeycomb fired bodies in which a large number of cells are arranged in parallel in the longitudinal direction with a cell wall interposed therebetween are provided via an adhesive layer. A honeycomb structure in which a coat layer is provided around a bound ceramic block, and the adhesive layer and the coat layer include inorganic fibers and inorganic particles, and the adhesive layer and the coat layer are separated from each other. The presence ratio of the inorganic particles and the presence ratio of the inorganic fibers are substantially the same on the surface side of the coat layer and the ceramic block side of the coat layer, respectively. is there.

In the honeycomb structure having such a configuration, the inorganic fibers and the inorganic particles contained in the coat layer are almost uniformly dispersed on the surface side and the ceramic block side, so that uniform strength can be obtained throughout the coat layer. . Moreover, since the unevenness | corrugation by the dispersion | distribution nonuniformity of an inorganic fiber and an inorganic particle has not arisen on the surface of a coating layer, it becomes a honeycomb structure with high surface strength and no powderiness.
Note that not only an example in which the bias toward the honeycomb fired body is suppressed for both the inorganic fibers and the inorganic particles contained in the coat layer, but also when the coat layer contains only one of the inorganic fibers or the inorganic particles. Further, by suppressing the bias of the inorganic fibers or inorganic particles toward the honeycomb fired body, it is possible to make the strength uniform and improve the surface smoothness in the above-described coating layer.

Examples that specifically disclose the first embodiment of the present invention are shown below. The present invention is not limited to this example. In Example 1 and Comparative Example 1, the cylindrical honeycomb structure shown in FIG. 1 was manufactured, and the obtained honeycomb structure was subjected to the following procedure for the presence or absence of migration and the presence or absence of dusting on the surface of the coat layer. evaluated.
For the presence or absence of migration in the coating layer, a sample is prepared by cutting the manufactured honeycomb structure in a direction perpendicular to the longitudinal direction, and the surface side of the coating layer and the state of the honeycomb fired body are observed with a scanning electron microscope (SEM). Was confirmed.
In addition, the presence or absence of dusting on the surface of the coat layer was observed by visually observing the surface of the coat layer and touching the surface of the coat layer with a finger to visually observe the presence or absence of powder adhesion.

Example 1
(Preparation of honeycomb molded body)
A silicon carbide coarse powder of 52.8% by weight having an average particle diameter of 22 μm and a silicon carbide fine powder of 22.6% by weight having an average particle diameter of 0.5 μm were mixed. Acrylic resin 2.1% by weight, organic binder (methylcellulose) 4.6% by weight, lubricant (Unilube made by NOF Corporation) 2.8% by weight, glycerin 1.3% by weight, and the resulting mixture Then, 13.8% by weight of water was added and kneaded to obtain a mixed composition. Extrusion molding was performed using this mixed composition, and the cells had the same shape as the honeycomb fired bodies 111, 112, and 113 shown in FIGS. 2 (a), 2 (b), and 2 (c). Each of the green honeycomb molded bodies without the above plugging was produced.

(Preparation of honeycomb fired body)
The raw honeycomb molded body was dried using a microwave dryer to obtain a dried honeycomb molded body. A paste having the same composition as that of the mixed composition was plugged into a predetermined cell of the dried body of the honeycomb formed body. And the drying process was again performed using the microwave dryer.

The dried honeycomb formed body is degreased at 400 ° C., and fired under conditions of 2200 ° C. and 3 hours under an atmospheric pressure of argon atmosphere, so that FIG. 2 (a), FIG. 2 (b), and FIG. A honeycomb fired body having the shape shown in 2 (c) was produced. The obtained honeycomb fired body has a porosity of 45%, an average pore diameter of 15 μm, a number of cells (cell density) of 300 / inch ² , and a cell wall thickness of 0.25 mm (10 mil). A honeycomb fired body made of a silicon sintered body.

(Assembling and fixing honeycomb fired body)
In Example 1, a mold having the shape shown in FIG. 4 and made of a dense stainless steel was used as the mold. A paper member was disposed on the inner surface side of the formwork. The paper member was attached to the inner surface of the mold with double-sided tape.
The mold made of a dense stainless steel has an outer diameter of 158 mm, an inner diameter of 142.8 mm, and a thickness of 7.6 mm. As the paper member, glassine paper subjected to silicon processing was used. This paper member is paper in which a release layer containing silicon is formed on the surface of glassine paper, has air permeability of 6.0 cc / cm ² / sec, and has a thickness of 0.075 mm.

Then, as shown in FIG. 4, 16 honeycomb fired bodies were assembled into a columnar shape through spacers inside the mold. The 16 assembled honeycomb fired bodies were aligned so as to be parallel to the longitudinal direction and to form the same plane on both end faces. The distance between the assembled honeycomb fired body and the inner surface of the mold was 1.0 mm, and the distance between the assembled honeycomb fired body and the paper member (d3 in FIG. 4) was 0.925 mm.

(Filling with sealing material paste)
The sealing material paste supply device shown in FIGS. 5A and 5B was mounted on a mold, and the sealing material paste was put into the paste chamber of the filling device. Then, as shown in FIGS. 6A and 6B, the gap between the mold frame and the honeycomb fired body and the gap between the honeycomb fired bodies were filled with the sealing material paste.
The sealing material paste includes 30% by weight of alumina fibers having an average fiber length of 20 μm, 21% by weight of silicon carbide particles having an average particle diameter of 0.6 μm, 15% by weight of silica sol (solid content 30% by weight), 5.6% by weight of carboxymethyl cellulose. % And a heat-resistant sealing material paste containing 28.4% by weight of water was used.

(Drying of sealing material paste)
Next, the mold filled with the sealing material paste was heat-treated at 120 ° C. to dry the sealing material paste. After the sealing material paste solidified, the mold was separated. Thereby, a cylindrical honeycomb structure (see FIG. 1) was obtained.

Regarding the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger. As a result, no dusting on the surface of the coat layer was observed. Furthermore, when the coating layer was observed by SEM, the presence ratio of the inorganic particles on the surface side of the coating layer and the existence ratio of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Comparative Example 1)
In Comparative Example 1, no paper member was arranged on the inner surface side of the mold. A mold made entirely of stainless steel was used. However, in order to improve the releasability, the inner surface of the mold was subjected to fluororesin processing. Except for this, a honeycomb structure was manufactured in the same manner as in Example 1.
When the coating layer of the obtained honeycomb structure was observed, the proportion of inorganic particles present on the surface side of the coating layer was smaller than the proportion of inorganic particles present on the ceramic block side of the coating layer. The presence ratio of inorganic fibers in the coating layer was less than the presence ratio of inorganic fibers on the ceramic block side of the coat layer, and migration occurred. In addition, dusting occurred on the surface of the coat layer. The reason for this will be described below with reference to FIGS. 8A and 8B. In addition, about the thing which makes the same structure as Fig.7 (a) and FIG.7 (b), the same code | symbol is attached | subjected and description is abbreviate | omitted.

FIG. 8A is a perspective view schematically showing the state of the mold in the drying step (S5) of Comparative Example 1. FIG. FIG. 8 (b) shows a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically showing the movement of moisture contained in the sealing material paste in contact with the inner surface of the mold in the drying step (S5) of Comparative Example 1. FIG. In FIG. 8B, arrows R1 and R2 indicate the movement direction of moisture contained in the sealing material paste 600a.

In the first comparative example, a mold 800 formed entirely of stainless steel is used, and no paper member is disposed on the inner surface side of the mold 800. Therefore, the entire mold 800 and the mold 800 are used. The inner surface side is not air permeable.
In the drying step (S5), the moisture contained in the sealing material paste 600b filled between the gaps 210 between the honeycomb fired bodies 110 is exposed from the end face of the honeycomb fired body 110 to the outside as in the first embodiment of the present invention. (In the direction of arrow P).
However, the moisture contained in the sealing material paste 600a filled in the gap between the inner surface of the mold 800 and the honeycomb fired body 110 moves as follows. As shown in FIG. 8B, the water vapor 710a that has moved to the honeycomb fired body 110 side is released to the outside through the honeycomb fired body 110 as indicated by an arrow R1. On the other hand, the water vapor 710b trying to move to the mold 800 side cannot move through the mold 800 as indicated by an arrow R2, and therefore moves to the honeycomb fired body 110 side. Therefore, the entire moisture contained in the sealing material paste 600a moves to the honeycomb fired body 110 side. Then, along with this, the inorganic fibers 720 and the inorganic particles 730 move to the honeycomb fired body 110 side, and the inorganic fibers 720 and the inorganic particles 730 in the sealing material paste 600a are biased. Migration occurs.

From the above results, when the sealing material paste is dried, by providing a member including a ventilation portion on the inner surface side of the mold that contacts the sealing material paste, moisture in the sealing material paste is not limited to the honeycomb fired body side. It was revealed that the honeycomb structure can be discharged from the ventilation portion to the outside, thereby suppressing the occurrence of migration and having an excellent surface strength.

(Second embodiment)
Hereinafter, a second embodiment which is an embodiment of a method for manufacturing a honeycomb structure of the present invention will be described.
In this embodiment, an example in which a nonwoven fabric is arranged as a member including a ventilation portion instead of the paper constituting the member including the ventilation portion in the first embodiment of the present invention will be described.
In addition, since the honeycomb structure manufactured in the present embodiment has the same configuration as the honeycomb structure according to the first embodiment of the present invention, detailed description thereof is omitted. Also, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals and the description thereof is omitted.

FIG. 9A is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the second embodiment of the present invention. is there.
In Fig.9 (a), the nonwoven fabric 413 as a member containing a ventilation part is arrange | positioned at the inner surface side of the formwork 411 which has the structure similar to said 1st embodiment. The nonwoven fabric 413 is fixed to the inner surface side of the mold 411 with a double-sided tape.

The nonwoven fabric 413 is a member that is excellent in dimensional stability, hardly stretches and shrinks even if it absorbs water (moisture absorption), and does not easily wrinkle. Accordingly, the surface of the obtained coating layer is less likely to be uneven. In addition, the nonwoven fabric 413 is a member having both a large pore diameter and a high porosity, and since it has open pores that communicate with few closed pores, high air permeability (air permeability) is obtained. It is suitable as a member including a ventilation part according to the present invention.
Air permeability of the nonwoven fabric 413 is desirably at 0.05cc ^/ cm 2 ^/ sec or ^more, and more preferably in the range of ^{0.05cc / cm 2 / sec~100cc / cm} 2 / sec, 1cc / cm more preferably in the range of ^{2 / sec~100cc / cm 2 / sec} , and particularly preferably in the range of ^{5cc / cm 2 / sec~100cc / cm} 2 / sec.
The average pore diameter of the nonwoven fabric 413 is desirably 0.1 μm to 50 μm, and more desirably 0.1 μm to 5 μm. The average pore diameter means the diameter when the pores are circular, and means the maximum diameter of the pores when the pores are not circular.

Examples of the fiber material constituting the nonwoven fabric 413 include polyester, acrylic, polypropylene, polyethylene, polyester, polyolefin, aramid, vinylon, and rayon.
In this embodiment, the polyester fiber nonwoven fabric which consists of polyester fibers can be used conveniently as a member containing a ventilation part.

FIG. 9B schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the second embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG.
In FIG. 9B, when the moisture 710 in the sealing material paste 600a becomes water vapor by heating, a part of the water vapor 710a moves to the honeycomb fired body 110 side as indicated by an arrow R, thereby It is discharged from the end face of the fired body 110 to the outside. Further, as shown by an arrow Q, a part of the water vapor 710b moves toward the nonwoven fabric 413 and is held by the nonwoven fabric 413, or is released to the outside from the end face of the nonwoven fabric 413 together with air containing water vapor.
Therefore, also in the second embodiment of the present invention, the movement direction of the moisture 710 contained in the sealing material paste 600a is not biased. Therefore, as in the first embodiment of the present invention, the sealing material paste is dried. The occurrence of migration can be suppressed.

In this embodiment, the effects (1) to (4) described in the first embodiment of the present invention can be exhibited.

Examples that specifically disclose the second embodiment of the present invention will be described below. The present invention is not limited to this example.
(Example 2)
In Example 2, the nonwoven fabric constituting the member including the ventilation portion in the mold shown in FIG. 9A has an air permeability of 6.0 cc / cm ² / sec and a thickness of 0.09 mm. A wet nonwoven fabric (product number PY120-03, manufactured by Awa Paper Co., Ltd.) with 100% polyester fiber having an average pore diameter of 14.2 μm and an average fiber diameter of 28 μm was disposed.
The distance between the assembled honeycomb fired body and the inner surface of the mold is 1.0 mm, and the distance between the assembled honeycomb fired body and the nonwoven fabric (corresponding to the length indicated by d3 in FIG. 9A) is 0. .91 mm.
Other than that, a honeycomb structure was produced in the same manner as in Example 1.

With respect to the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger, and no dusting on the surface of the coat layer was observed. Further, when the coating layer was observed by SEM, the proportion of the inorganic particles on the surface side of the coating layer and the proportion of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Third embodiment)
Hereinafter, a third embodiment, which is an embodiment of a method for manufacturing a honeycomb structure of the present invention, will be described.
In the present embodiment, an example will be described in which paper as a member further including a ventilation portion is arranged on the inner surface side of a mold formed of a porous metal having air permeability. That is, in the present embodiment, both the entire mold and the paper member disposed on the inner surface side have air permeability. Moreover, the paper member arrange | positioned at the inner surface side of a formwork also plays the role which suppresses the movement of the inorganic particle and inorganic fiber which are contained in a coat layer, and improves the surface smoothness of a coat layer.
Note that the entire formwork includes a ventilation part means that the main part of the formwork that holds the assembled honeycomb structure has air permeability. As long as the effect of the present embodiment is not hindered, there may be a portion without air permeability.
Since the honeycomb structure manufactured in the present embodiment has the same configuration as that of the honeycomb structure according to the first embodiment of the present invention, detailed description thereof will be omitted. Also, components having the same configuration as those of the above embodiments are denoted by the same reference numerals and description thereof is omitted.

FIG. 10 (a) is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold in the third embodiment of the present invention. is there.
In FIG. 10A, a mold 421 is a porous metal mold that is entirely formed of a porous metal.
Examples of the porous metal include foam metal and metal nonwoven fabric. Here, a description will be given by taking as an example a mold formed of foam metal. In addition, a metal nonwoven fabric can be made into a formwork shape by laminating a plurality of sheets and spot welding, and can have strength as a formwork.
The pore diameter of the porous metal is desirably 50 μm to 600 μm, and more desirably 300 μm to 600 μm. The porous metal has such fine pores (continuous pores), and the porosity is desirably 80% to 97%, and more desirably 94% to 97%.
Specific materials for the porous metal include copper, nickel, stainless steel, or an alloy using at least one of these metals.
Since the mold 421 has fine holes as described above, the entire mold 421 including the inner surface 421a side of the mold 421 has air permeability. In addition, since the mold 421 having such a configuration is formed of a porous metal, it has sufficient strength for fixing the honeycomb fired body. Therefore, the formwork 421 according to the third embodiment of the present invention has both air permeability and strength.

Paper 412 is disposed on the inner surface side of the formwork 421. The paper 412 can be the same as that of the first embodiment of the present invention described above, and is affixed to the inner surface 421a of the mold 421 with a double-sided tape, for example.

FIG.10 (b) is the perspective view which showed typically the state of the formwork in drying process (S5) in 3rd embodiment of this invention. FIG. 11 (a) shows a third embodiment of the present invention in a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically illustrating the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold. FIG.

As shown in FIGS. 10B and 11A, when the moisture 710 in the sealing material paste 600a becomes water vapor by heating, a part of the water vapor 710a is converted into the honeycomb fired body 110 as shown by an arrow R. As shown by an arrow P, the honeycomb fired body 110 is discharged from the end face to the outside. A part of the water vapor 710 b passes through the paper 412 and the mold 421 and is released to the outside as indicated by an arrow Q. Further, a part of the water vapor 710 b that has moved to the paper 412 side is released from the end face of the paper 412 to the outside as indicated by an arrow S.
Therefore, even if the mold 421 according to the third embodiment of the present invention is used, the moving direction of the moisture 710 contained in the sealing material paste 600a does not deviate, so that the sealing is performed as in the first embodiment of the present invention. Occurrence of migration during the drying process of the material paste can be suppressed.

In the third embodiment of the present invention, the mold 421 formed of a porous metal has a strength as a mold for fixing the honeycomb fired body, and includes a ventilation portion having air permeability. Therefore, even if it is only the formwork 421, generation | occurrence | production of the migration in a coating layer can be suppressed similarly to above-described 1st embodiment and 2nd embodiment of this invention.
However, the pore diameter of the porous metal is usually considerably larger than the average particle diameter of the inorganic particles contained in the coat layer and the average fiber diameter of the inorganic fibers. Therefore, when the above-described sealing material paste is dried, when the inorganic particles and the inorganic fibers move to the surface side of the coat layer due to the movement of moisture contained in the coat layer, some unevenness is generated on the surface of the coat layer.
Here, in this embodiment, a paper member including a ventilation portion having an average pore diameter relatively smaller than the pore diameter of the porous metal is disposed on the inner surface side of the mold made of the porous metal. As a result, when the sealant paste is dried, the paper 412 allows air (water vapor) smaller than the pore diameter to pass therethrough and move to the mold side, but makes it difficult for the inorganic particles and inorganic fibers to pass therethrough. The movement can be suppressed.
Therefore, in this embodiment, the surface unevenness | corrugation by an inorganic particle and / or an inorganic fiber is eliminated, and the coating layer excellent in surface smoothness is realizable.
Further, since the paper 412 has good releasability, it can be easily peeled off from the honeycomb structure when released, and the releasability of the honeycomb structure can be improved.

In the present embodiment, the effects (1), (3), and (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.

(5) In the method for manufacturing a honeycomb structure according to the third embodiment of the present invention, both the mold frame made of porous metal and the paper member arranged on the inner surface side of the mold frame have a ventilation portion. Air permeability can be imparted by the porous metal mold and the paper member.

Hereinafter, examples more specifically disclosing the third embodiment of the present invention will be shown. The present invention is not limited to this example.
(Example 3)
In Example 3, a mold made of a porous metal having the shape shown in FIG. 10A was used as the mold. The porous metal is a stainless steel foam metal (manufactured by Mitsubishi Materials Corporation, standard porosity of 95% to 97%). The mold has an outer shape of 158 mm, an inner diameter of 142.8 mm, and a thickness of 7.6 mm, and has an air permeability of 6.0 cc / cm ² / sec.
The paper member arranged on the inner surface side of the mold was the same as that in Example 1.
The distance between the assembled honeycomb fired body and the inner surface of the mold is 1.0 mm, and the distance between the assembled honeycomb fired body and the paper (corresponding to the length indicated by d3 in FIG. 10A) is 0. 925 mm.
The other conditions were the same as in Example 1, and a honeycomb structure having the shape shown in FIG. 1 was produced.

With respect to the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger, and no dusting on the surface of the coat layer was observed. Further, when the coating layer was observed by SEM, the proportion of the inorganic particles on the surface side of the coating layer and the proportion of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Fourth embodiment)
Hereinafter, a fourth embodiment which is an embodiment of a method for manufacturing a honeycomb structure of the present invention will be described.
This embodiment has a configuration in which the paper member in the third embodiment of the present invention is changed to a nonwoven fabric member. Since the other configuration is the same as that of the third embodiment of the present invention, detailed description is omitted. Also, components having the same configuration as those of the above embodiments are denoted by the same reference numerals and description thereof is omitted.
The nonwoven fabric member is the same as that of the second embodiment of the present invention described above. The nonwoven fabric member is affixed to the inner surface side of the mold with double-sided tape.

In the fourth embodiment of the present invention, the mold formed of a porous metal has a strength as a mold for fixing the honeycomb fired body, and includes a ventilation portion having air permeability. That is, in this embodiment, both a formwork and a nonwoven fabric member contain a ventilation part.
Moreover, the nonwoven fabric member arrange | positioned at the inner surface side of a formwork has the effect of improving mold release property while including a ventilation part. Furthermore, the ventilation part contained in the nonwoven fabric member has an average pore diameter that is relatively smaller than the pore diameter of the porous metal. Thereby, when the sealing material paste is dried, the nonwoven fabric member allows air (water vapor) smaller than the pore diameter to pass therethrough and move to the mold side, but makes it difficult for the inorganic particles and inorganic fibers to pass therethrough. The movement can be suppressed.
Therefore, in this embodiment, the surface unevenness | corrugation by an inorganic particle and / or an inorganic fiber is eliminated, and the coating layer excellent in surface smoothness is realizable.
Furthermore, since the nonwoven fabric member has good releasability, it can be easily peeled off from the honeycomb structure when released, and the releasability of the honeycomb structure can be improved.

FIG. 11B schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the fourth embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG.
In FIG. 11 (b), when the moisture 710 in the sealing material paste 600a becomes water vapor by heating, a part of the water vapor 710a moves to the honeycomb fired body 110 side as indicated by an arrow R, and the honeycomb paste 710a moves to the honeycomb fired body 110 side. It is discharged from the end face of the fired body 110 to the outside. Further, a part of the water vapor 710b moves through the nonwoven fabric 432 and the mold 421 in the direction of the arrow Q and is released to the outside. Further, a part of the water vapor 710b that has moved to the nonwoven fabric 432 side is released from the end surface of the nonwoven fabric 432 to the outside in the same manner as the water vapor released from the end surface of the paper member according to the third embodiment of the present invention.
Therefore, also in the fourth embodiment of the present invention, the movement direction of the moisture 710 contained in the sealing material paste 600a is not biased. Therefore, as in the third embodiment of the present invention, during the drying treatment of the sealing material paste The occurrence of migration can be suppressed.

In the present embodiment, the effects (1), (3), and (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.

(6) In the method for manufacturing a honeycomb structured body according to the fourth embodiment of the present invention, both the mold frame made of porous metal and the nonwoven fabric member arranged on the inner surface side of the mold frame have ventilation portions, Air permeability can be imparted by the porous metal mold and the nonwoven fabric member.

Hereinafter, examples that more specifically disclose the fourth embodiment of the present invention will be described. The present invention is not limited to this example.
Example 4
In Example 4, the same porous metal mold as in Example 3 was used as the mold.
The nonwoven fabric member arranged on the inner surface side of the mold was the same as in Example 2.
The distance between the assembled honeycomb fired body and the inner surface of the mold is 1.0 mm, and the distance between the assembled honeycomb fired body and the nonwoven fabric member (corresponding to the length indicated by d3 in FIG. 10 (a)) is It was 0.91 mm.
Otherwise, a honeycomb structure having the shape shown in FIG. 1 was produced in the same manner as in Example 1.

With respect to the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger, and no dusting on the surface of the coat layer was observed. Further, when the coating layer was observed by SEM, the proportion of the inorganic particles on the surface side of the coating layer and the proportion of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Fifth embodiment)
Hereinafter, a fifth embodiment, which is an embodiment of a method for manufacturing a honeycomb structure of the present invention, will be described.
In the present embodiment, the paper member is changed to a mesh member in the third embodiment of the present invention. Since the other configuration is the same as that of the third embodiment of the present invention, detailed description is omitted. Also, components having the same configuration as those of the above embodiments are denoted by the same reference numerals and description thereof is omitted.

Examples of the mesh member as a member including the ventilation portion include a metal mesh member or a resin mesh member.
Examples of the metal mesh member include members including meshes such as stainless steel, nickel, titanium, copper, and zinc. Among these, stainless steel mesh members are desirable because they are less prone to rust and are easily available.
Examples of the resin mesh member include members including meshes such as PA (polyamide), PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PPS (polyphenylene sulfide), and fluorine resin. In the present embodiment, it is desirable to use a resin mesh member having heat resistance higher than the drying temperature of the coat layer.

Air permeability of the mesh member is desirably 0.05cc ^/ cm 2 ^/ sec or ^more, and more preferably in the range of ^{0.05cc / cm 2 / sec~100cc / cm} 2 / sec, 1cc / cm more preferably in the range of ^{2 / sec~100cc / cm 2 / sec} , and particularly preferably in the range of ^{5cc / cm 2 / sec~100cc / cm} 2 / sec.
As a mesh member, a thing with a small opening is desirable, For example, the thing of 325 mesh-795 mesh can be used. As an example, in the case of a stainless mesh member, it may be either a twill or plain weave, a wire diameter of 0.015 mm to 0.035 mm, an aperture of 0.016 mm to 0.062 mm, and an aperture ratio of 24.9% to 60 0.0% can be preferably used.
In the present specification, the mesh member includes a punching metal member.
The punching metal member is a member in which a large number of holes are formed in a fixed arrangement in a metal plate, and the shape, pitch, opening diameter, etc. of the holes are not particularly limited as long as they have the above air permeability. Absent.

Hereinafter, the case where a stainless mesh member is used as the mesh member will be described as an example.
The stainless mesh member is formed in a substantially cylindrical shape having an inner diameter slightly smaller than the inner diameter of the mold in consideration of its thickness so as to come into contact with the inner surface of the mold when arranged on the inner surface side of the mold. Since the stainless mesh member having such a shape has a self-supporting property, the ventilation portion can be configured only by being disposed on the inner surface of the mold.

In the fifth embodiment of the present invention, a mold formed of a porous metal has a strength as a mold for fixing the honeycomb fired body, and includes a ventilation portion having air permeability. That is, in this embodiment, both the formwork and the stainless mesh member include a ventilation portion.
Further, the stainless mesh member disposed on the inner surface side of the mold frame has an effect of improving the mold release property while including the ventilation portion. Furthermore, when the opening of the stainless mesh member is relatively smaller than the pore diameter of the porous metal, when the sealant paste is dried, air (water vapor) is permeated and moved to the mold side. Inorganic particles and inorganic fibers can be made difficult to permeate and their movement can be suppressed.
Therefore, in this embodiment, the surface unevenness | corrugation by an inorganic particle and / or an inorganic fiber is eliminated, and the coating layer excellent in surface smoothness is realizable.

FIG. 11 (c) schematically shows the movement of moisture contained in the sealing material paste in contact with the inner surface side of the mold in the fifth embodiment of the present invention, in a direction perpendicular to the longitudinal direction of the honeycomb fired body. FIG.
In FIG. 11C, when the moisture 710 in the sealing material paste 600a becomes water vapor by heating, a part of the water vapor 710a moves to the honeycomb fired body 110 side as indicated by an arrow R, and the Released from the end face of the fired body 110 to the outside. Further, a part of the water vapor 710b moves in the direction of arrow Q through the stainless steel mesh 442 and the mold 421, and is released to the outside.
Therefore, even if the mold 421 and the stainless steel mesh 442 according to the fifth embodiment of the present invention are used, the moving direction of the moisture 710 contained in the sealing material paste 600a is not biased, so the first embodiment of the present invention described above. Similarly to the above, it is possible to suppress the occurrence of migration during the drying process of the sealing material paste.

In the present embodiment, the effects (1), (3), and (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.

(7) In the method for manufacturing a honeycomb structure according to the fifth embodiment of the present invention, the mold frame made of porous metal and the mesh member arranged on the inner surface side of the mold frame both have a ventilation portion. Air permeability can be imparted by the porous metal mold and the mesh member.

Hereinafter, examples that more specifically disclose the fifth embodiment of the present invention will be described. The present invention is not limited to this example.
(Example 5)
In this example, the same porous metal mold as in Example 3 was used as the mold.
A stainless mesh member was placed on the inner surface side of the mold. The stainless mesh member has 795 mesh, a wire diameter of 0.016 mm, an aperture of 0.016 mm, an aperture ratio of 24.9%, and an air permeability of 0.05 cc / cm ² / sec or more.
The distance between the assembled honeycomb fired body and the inner surface of the mold is 1.0 mm, and the distance between the assembled honeycomb fired body and the stainless mesh member (corresponding to the length indicated by d3 in FIG. 9A) is 0.984 mm.
Other than that, a honeycomb structure was produced in the same manner as in Example 1.

With respect to the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger, and no dusting on the surface of the coat layer was observed. Further, when the coating layer was observed by SEM, the proportion of the inorganic particles on the surface side of the coating layer and the proportion of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Sixth embodiment)
Hereinafter, a sixth embodiment, which is an embodiment of a method for manufacturing a honeycomb structure of the present invention, will be described.
In the third to fifth embodiments of the present invention, the mold made of porous metal and the paper member, the nonwoven fabric member, or the stainless mesh member arranged on the inner surface side have a ventilation portion. However, in this embodiment, an example in which only a mold made of a porous metal has a ventilation portion will be described. Since other configurations are the same as those of the third to fifth embodiments of the present invention, detailed description is omitted. Also, components having the same configuration as those of the above embodiments are denoted by the same reference numerals and description thereof is omitted.

FIG. 12 is a cross-sectional view taken along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is arranged inside the mold according to the sixth embodiment of the present invention.
In FIG. 12, a mold 421 is a porous metal mold that is entirely formed of a porous metal.

In the sixth embodiment of the present invention, the mold 421 formed of a porous metal has a strength as a mold for fixing the honeycomb fired body, and includes a ventilation portion having air permeability.

FIG. 13A is a perspective view schematically showing the state of the mold in the drying step (S5) in the sixth embodiment of the present invention. FIG. 13 (b) shows a direction perpendicular to the longitudinal direction of the honeycomb fired body for schematically showing the movement of moisture contained in the sealing material paste in contact with the inner surface of the mold in the sixth embodiment of the present invention. FIG.
As shown in FIGS. 13A and 13B, when the moisture 710 in the sealing material paste 600a becomes water vapor by heating, a part of the water vapor 710a is converted into the honeycomb fired body 110 as shown by an arrow R. And is discharged from the end face of the honeycomb fired body 110 to the outside. A part of the water vapor 710b moves in the direction of arrow Q through the mold 421 and is released to the outside.
Therefore, also in the sixth embodiment of the present invention, the movement direction of the moisture 710 contained in the sealing material paste 600a is not biased. Therefore, as in the first embodiment of the present invention, during the drying treatment of the sealing material paste The occurrence of migration can be suppressed.

In the present embodiment, the effects (1), (3), and (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.

(8) In the method for manufacturing a honeycomb structured body according to the sixth embodiment of the present invention, air permeability can be imparted by the porous metal mold.

Examples that specifically disclose the sixth embodiment of the present invention will be described below. The present invention is not limited to this example.
(Example 6)
In Example 6, a metal mold made of foam metal having the same configuration as that of Example 3 was used except that the inner diameter was different. Otherwise, a honeycomb structure having the shape shown in FIG. 1 was produced in the same manner as in Example 1. The interval between the assembled honeycomb fired body and the formwork (corresponding to d3 in FIG. 12) was 0.925 mm.

With respect to the obtained honeycomb structure, the surface of the coat layer was visually observed and touched with a finger, and no dusting on the surface of the coat layer was observed. Further, when the coating layer was observed by SEM, the proportion of the inorganic particles on the surface side of the coating layer and the proportion of the inorganic particles on the honeycomb fired body side of the coating layer were substantially the same, and the surface of the coating layer The existence ratio of the inorganic fibers on the side and the existence ratio of the inorganic fibers on the honeycomb fired body side of the coat layer were substantially the same, and no migration was observed in the coat layer.

(Seventh embodiment)
Hereinafter, a seventh embodiment, which is an embodiment of a method for manufacturing a honeycomb structure of the present invention, will be described.
In the present embodiment, in the fixing step (S3), the honeycomb fired body is fixed by holding both end faces of the honeycomb fired body.
Since the honeycomb structure manufactured in the present embodiment has the same configuration as that of the honeycomb structure according to the first embodiment of the present invention, detailed description thereof will be omitted. Also, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals and the description thereof is omitted.

In the first embodiment of the present invention, when the honeycomb fired body 110 is assembled into a columnar shape, the honeycomb fired body 110 is fixed using the spacers 405 as shown in FIG. 4, but in this embodiment, the honeycomb fired body 110 is fixed. Both end faces of 110 are fixed using fixing pins.

14 (a), 14 (b), 14 (c), 14 (d), and 14 (e) illustrate a fixing process of the honeycomb fired body according to the seventh embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a state along the direction perpendicular to the longitudinal direction of the honeycomb fired body with respect to the arrangement of the honeycomb fired body in the mold. The formwork is the formwork 411 according to the first embodiment of the present invention, and the paper 412 is arranged on the inner surface side thereof.

In FIG. 14A, two honeycomb fired bodies 111 and two honeycomb fired bodies 112 are disposed inside a mold 411 in which paper 412 is disposed on the inner surface 411a side, and the honeycomb fired body 112 is a honeycomb fired body. It arrange | positions so that it may be pinched | interposed by 111. A certain distance is provided between the honeycomb fired body 111 and the honeycomb fired body 112, and between the honeycomb fired bodies 111 and 112 and the inner surface 411a of the mold 411 so that a sealing material paste can be filled in a subsequent process. .
The honeycomb fired bodies 111 and 112 are transported and arranged using, for example, a robot arm or a transport member provided with a mounting surface on which four honeycomb fired bodies 110 can be placed at a time.

Next, as shown in FIG. 14B, both end faces of the honeycomb fired bodies 111 and 112 arranged in the mold 411 are fixed with fixing pins 700 as holding members. The fixing pin 700 holds the honeycomb fired bodies 111 and 112 so that the end faces of the honeycomb fired bodies 111 and 112 are aligned on the same plane.

Next, as shown in FIG. 14C, two honeycomb fired bodies 112 and two honeycomb fired bodies 113 are sandwiched between the honeycomb fired bodies 112 on the inner surface side of the mold 411. To be arranged. In the same manner as described above, both end faces of the honeycomb fired bodies 112 and 113 are fixed by the fixing pins 700.

Next, as shown in FIG. 14 (d), the two honeycomb fired bodies 112 and the two honeycomb fired bodies 113 are arranged in the same manner as described above and fixed by the fixing pins 700. Further, as shown in FIG. 14 (e), the two honeycomb fired bodies 111 and the two honeycomb fired bodies 112 are arranged in the same manner as described above and fixed by the fixing pins 700.

In this way, the 16 honeycomb fired bodies 111, 112, and 113 constituting the honeycomb structure can be arranged so as to be parallel to the length direction and have the same end faces.

In the above description, a method of positioning a plurality of honeycomb fired bodies 110 at predetermined positions and holding both end surfaces of the honeycomb fired bodies 110 with fixing pins 700 as holding members has been described. This method is not limited to the method of holding and holding between the holding members, and a method of holding both end faces of the honeycomb fired body 110 by holding the holding members is also applicable.
In the above description, the member including the mold and the ventilation portion is described as an example of the member including the mold and the ventilation portion. However, the mold according to the other embodiment is described as an example. And this embodiment is applicable also to the member containing a ventilation part.

In the seventh embodiment of the present invention, the effects (1) to (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.
(9) In the method for manufacturing a honeycomb structured body according to the seventh embodiment of the present invention, in the fixing step, the honeycomb fired body is fixed by holding both end faces of the honeycomb fired body. Easy to hold in shape.

In the seventh embodiment of the present invention described above, a holding member configured to be able to hold each honeycomb fired body is used, but the holding member includes a plurality of honeycomb fired bodies. You may be comprised so that it may contact | abut to an end surface and the said some honeycomb fired body can be hold | maintained collectively.

(Eighth embodiment)
Hereinafter, an eighth embodiment which is an embodiment of a method for manufacturing a honeycomb structured body of the present invention will be described.
In the first to sixth embodiments of the present invention, each embodiment has been described with specific examples of the ventilation portion. In addition to these, a plurality of concave portions and / or convex portions are formed by a metal member formed. The vent part to be used can also be used as the vent part in the present invention. In the present embodiment, a case where the inner surface of a mold having a plurality of recesses formed on the inner surface has a ventilation portion will be described as an example.
Since the honeycomb structure manufactured in the present embodiment has the same configuration as that of the honeycomb structure according to the first embodiment of the present invention, detailed description thereof will be omitted. Also, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals and the description thereof is omitted.

FIG. 15 is a cross-sectional view along a direction perpendicular to the longitudinal direction of the honeycomb fired body, schematically showing a state in which the honeycomb fired body is disposed inside the mold according to the eighth embodiment of the present invention.
In FIG. 15, a plurality of recesses 462 are formed on the inner surface 461a of a mold 461 made of a dense metal. The depth and width of the recess 462 are not particularly limited, and can be appropriately set according to desired air permeability. As a metal material constituting the mold 461, copper, nickel, stainless steel, or an alloy using at least one of these metals can be used.
The mold 461 is made of a dense metal having no air permeability. However, since a plurality of recesses 462 are formed on the inner surface, water vapor can escape to the recesses 462 when the sealing material paste is dried. it can. That is, the plurality of recesses 462 can form a ventilation portion.
Even if the mold 460 configured as described above is used, the movement direction of moisture contained in the sealing material paste is not biased. Therefore, as in the first to sixth embodiments, Occurrence of migration during the drying process can be suppressed.

In the above description, the example in which the concave portion is formed on the inner surface of the mold is described. However, the present embodiment is not limited to this, and a convex portion is formed on the inner surface of the mold in place of the concave portion. It may be. Moreover, both the recessed part and the convex part may be formed in the inner surface of a formwork. Even with such a configuration, a space is created by a concave portion or a convex portion between the sealing material paste for forming the coat layer and the inner surface of the mold, so that moisture contained in the sealing material paste can be transferred through this space. Can contribute.

Since the formwork according to the eighth embodiment of the present invention has the concave portion and / or the convex portion formed on the inner surface side, the resulting honeycomb structure is likely to have irregularities formed on the surface of the coat layer.
When the honeycomb structure is used in an exhaust gas purification apparatus, for example, a holding sealing material (mat made of inorganic fibers) is wound around the outer peripheral surface of the coat layer and inserted into a metal case. At this time, if the surface of the coat layer is uneven as described above, the holding sealing material fits into the concave portion or the holding sealing material fits into the convex portion, so that the honeycomb structure comes off from the metal case during use. It can be difficult.
In addition, when a convex portion is formed on the surface of the coat layer, the surface of the coat layer may be flattened by performing a polishing process or the like.

In the eighth embodiment of the present invention, a paper member, a non-woven member, or the same as in the first to fifth embodiments of the present invention, on the inner surface side of the mold having the irregularities formed on the inner surface as described above. A mesh member or the like may be arranged.

In this embodiment, the effects (1) to (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.
(10) In the method for manufacturing a honeycomb structured body according to the eighth embodiment of the present invention, the ventilation portion is formed by a metal member having a plurality of concave portions and / or convex portions formed on the inner surface. Air permeability can be imparted by the convex portions.

(Ninth embodiment)
The ninth embodiment, which is an embodiment of the method for manufacturing a honeycomb structure of the present invention, will be described below.
In each of the embodiments described above, an integrally formed mold was used as a mold for fixing the assembled honeycomb fired body. However, in the ninth embodiment of the present invention, a mold that can be divided into two is used. explain.

FIG. 16 schematically shows a state in which a honeycomb fired body is arranged inside a mold that can be divided into two mold members in the ninth embodiment of the present invention, perpendicular to the longitudinal direction of the honeycomb fired body. It is sectional drawing which follows an arbitrary direction.
In FIG. 16, the formwork 470 includes a pair of formwork members 470a and a formwork member 470b.
In the fixing step (S3), the honeycomb fired body is pumped into a desired shape inside the mold member 470a. Then, the formwork member 470b is combined with the formwork member 470a, and both are fixed using the bolt 471 and the nut 472.
By using the mold 470 having such a configuration, the mold member 470a and the mold member 470b can be divided after the sealing material paste is hardened to some extent by heat treatment or the like. It can be easily taken out. Then, the taken-out honeycomb structure is moved to another place, and the sealing material paste can be further dried at a predetermined temperature.

In the above description, a mold that can be divided into two parts has been described as an example, but the present embodiment is not limited to this. That is, the formwork is not particularly limited as long as the assembled honeycomb fired body can be held inside, and various forms such as a formwork that can be divided into a plurality of members can be applied as necessary. Further, the method of dividing the formwork is not particularly limited, and it may be divided into a plurality of parts in a direction perpendicular to the longitudinal direction of the honeycomb structure, or may be divided into a plurality of parts in a direction parallel to the longitudinal direction. Good. Further, the material forming the mold may be a dense metal or a porous metal.

In this embodiment, the effects (1) to (4) described in the first embodiment of the present invention can be exhibited, and the following effects can be exhibited.
(11) In the method for manufacturing a honeycomb structured body according to the ninth embodiment of the present invention, the mold frame can be separated into a plurality of members. Therefore, the mold material is separated and the sealing material paste is completely cured. Since the manufactured honeycomb structure can be taken out from the mold before, the heated honeycomb structure can be cooled in a short time. Thereby, the hardening time of a sealing material paste can be shortened and the productivity of a honeycomb structure can be improved.

(Other embodiments)
In the present invention, it is desirable that the mold has a coating layer made of a fluororesin or the like formed on the inner surface of any of the above-described mold made of dense metal or metal mold made of porous metal. When such a coating layer is formed, the releasability of the honeycomb structure can be improved. In addition, since the coating layer has good releasability, when a member further including a ventilation portion is provided on the inner surface side of the mold, when the member including the ventilation portion needs to be replaced due to clogging or the like, The member including the ventilation part can be easily peeled off, and workability can be improved.
The coating layer may be partially formed so as not to fill all the pores of the porous metal.

Further, in the present invention, the mold is not limited to the above-described mold made of a dense metal or a metal mold made of a porous metal, but a dense metal layer whose outer surface is formed of a dense metal. A formwork or the like in which the inner surface side is formed of a porous metal layer formed of a porous metal and both are integrally formed can also be applied. The ratio between the dense metal layer and the porous metal layer may be appropriately set in consideration of the strength as a mold and the air permeability of the porous metal layer including the ventilation portion.

In the present invention, the member including the ventilation portion is not limited to the member including the ventilation portion described in the above embodiments, and various members can be applied. For example, not only a paper member, a nonwoven fabric member, or a mesh member is disposed on the inner surface side of the mold, but a porous resin layer is formed on the inner surface of the mold, or a porous carbon layer is formed. The member including the ventilation portion can also be configured. Furthermore, a member including a ventilation portion can be configured by combining a plurality of paper members, nonwoven fabric members, mesh members, porous resin layers, or porous carbon layers. These combinations and arrangements are not particularly limited, and may be appropriately set in consideration of air permeability, peelability, pore diameter, and the like.

The porous resin layer is not particularly limited. For example, the porous resin layer is selected from fluorine resins such as polytetrafluoroethylene, polychlorotrifluoroethylene, ethylene fluoride, tetrafluoroethylene, and polyvinylidene fluoride, and polypropylene. Formed of at least one kind. Moreover, the porosity, the hole diameter, etc. of a porous resin layer are set suitably.
As an example of the porous resin layer, a polypropylene film (manufactured by Sumitomo 3M Co., Ltd., microporous film) having an average pore diameter of 0.3 μm can be mentioned. This polypropylene film is a porous film composed of polypropylene and an organic filler, and has both air permeability and waterproofness. Moreover, a tetrafluoroethylene resin porous membrane (manufactured by Nitto Denko Corporation, trade name Temisch) having an average pore diameter of 0.6 μm can be mentioned.
The porous resin layer can be formed, for example, by applying the above-described resin to the inner surface of a mold made of a porous metal. In this case, since the porous resin layer is integrally formed on the inner surface of the mold, the mold made of porous metal and the porous resin layer can be said to be a mold.

The shape of the honeycomb structure obtained by the manufacturing method of the present invention is not limited to the columnar shape shown in FIG. 1, but may be any columnar shape such as an elliptical columnar shape, a long columnar shape, or a polygonal columnar shape. .
Further, the number of honeycomb fired bodies constituting the honeycomb structure is not limited to 16 as in the embodiment of the present invention, and may be more or less than 16.

In each of the embodiments of the present invention described above, an example in which a honeycomb fired body is assembled inside a mold has been described. However, the present invention is not limited to this, and a plurality of honeycomb fired bodies are formed in a predetermined shape. In addition, the honeycomb fired body may be disposed inside the mold in a state where both end faces of the honeycomb fired body are held and fixed by a holding member or the like.

The porosity of the honeycomb fired body obtained by the method for manufacturing a honeycomb structure of the present invention is preferably 30% to 70% when used as a honeycomb filter. By having such a porosity, the strength of the honeycomb structure can be maintained, and the resistance when the exhaust gas passes through the cell walls can be kept low. If the porosity of the honeycomb fired body is less than 30%, the cell wall may be clogged early. On the other hand, if the porosity of the honeycomb fired body exceeds 70%, the strength of the honeycomb fired body decreases. It can be easily destroyed.
The porosity of the honeycomb fired body can be measured by a mercury intrusion method.

The cell density in the cross section perpendicular to the longitudinal direction of the honeycomb fired body is not particularly limited, but the desirable lower limit is 31.0 / cm ² (200 / in ² ), and the desirable upper limit is 93.0 / cm ^2. (600 / in ² ), a more desirable lower limit is 38.8 / cm ² (250 / in ² ), and a more desirable upper limit is 77.5 / cm ² (500 / in ² ).

The main component of the constituent material of the honeycomb fired body is not limited to silicon carbide, and as other ceramic raw materials, for example, nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, titanium nitride, zirconium carbide, It may be a carbide ceramic such as titanium carbide, tantalum carbide or tungsten carbide, a composite of metal and nitride ceramic, a composite of metal and carbide ceramic, or the like.
Moreover, ceramic raw materials, such as a silicon-containing ceramic in which metallic silicon is blended with the above-described ceramic, or a ceramic bonded with silicon or a silicate compound, can be cited as a constituent material. Among these, as the constituent material of the honeycomb fired body, silicon carbide or silicon-containing ceramic having excellent mechanical strength is desirable.

In each of the embodiments of the present invention described above, a method for manufacturing a honeycomb structure used as an exhaust gas purification filter in which a cell at one end is sealed with a sealing material has been described. Is not limited to this. The honeycomb structure may be a honeycomb structure in which none of the end portions of the cells are sealed with a sealing material. Such a honeycomb structure can be used as a catalyst carrier for supporting a catalyst on a cell wall.

100 honeycomb structure 101 ceramic block 102 coat layer 103 adhesive layer 110 (111, 112, 113) honeycomb fired body 111a (112a, 113a) cell 111b (112b, 113b) cell wall 210 (220) gap 411 (420, 421) , 431, 441, 451, 460, 461) Formwork 411a (420a, 421a, 431a, 441a, 460a, 461a, 470a, 470a, 470b) Inner surface 600 (600a, 600b) of the formwork Sealing material paste

Claims (17)

A honeycomb structure in which a columnar honeycomb fired body in which a large number of cells are arranged side by side across a cell wall is provided with a coat layer around a ceramic block in which a plurality of cells are bound via an adhesive layer. A manufacturing method comprising:
A molding step of extruding a honeycomb molded body having cell walls formed on the outer periphery,
A firing step of firing the honeycomb formed body to form a honeycomb fired body;
A fixing step of fixing a plurality of honeycomb fired bodies in a mold,
A filling step of filling a gap between the mold frame and the honeycomb fired body and a gap between the honeycomb fired bodies with a sealing material paste;
A drying step of drying and solidifying the sealing material paste to form the adhesive layer and the coat layer,
The sealing material paste includes inorganic particles and / or inorganic fibers,
The member disposed on the mold, the inner surface of the mold, or the inner surface of the mold is provided with a ventilation portion having air permeability.
In the drying step, the sealing material paste is brought into contact with at least a part of the ventilation portion to dry and solidify the sealing material paste. The mold is any one of a mold formed of a dense metal, a mold formed of a porous metal, and a mold made of a dense metal having a plurality of concave portions and / or convex portions formed on the inner surface. The method for manufacturing a honeycomb structured body according to claim 1. The honeycomb structure according to claim 1 or 2, wherein the member disposed on the inner surface side of the mold is made of at least one selected from a paper member, a nonwoven fabric member, a mesh member, a porous resin layer, and a porous carbon layer. Manufacturing method. The method for manufacturing a honeycomb structured body according to claim 3, wherein the ventilation portion has an average pore diameter of 0.1 µm to 50 µm. The method for manufacturing a honeycomb structured body according to any one of claims 1 to 4, wherein air permeability of the mold or a member disposed on an inner surface side of the mold is 0.05 cc / cm ² / sec or more. The mold and the member disposed on the inner surface side of the mold include a ventilation portion,
The mold is made of a porous metal,
The method for manufacturing a honeycomb structure according to claim 1, wherein the member is a paper member or a nonwoven fabric member. The member disposed on the inner surface side of the formwork includes a ventilation portion,
The member is a paper member or a non-woven member,
The method for manufacturing a honeycomb structured body according to claim 1, wherein the mold is made of a dense metal. The method for manufacturing a honeycomb structure according to any one of claims 3, 6, and 7, wherein the paper member is a paper member subjected to silicon processing. The method for manufacturing a honeycomb structured body according to claim 8, wherein an average pore diameter of a ventilation portion provided in the silicon-processed portion is 20 µm to 50 µm. The honeycomb according to any one of claims 2, 6, and 7, wherein the porous metal or the dense metal constituting the mold is copper, nickel, stainless steel, or an alloy using at least one of these metals. Manufacturing method of structure. The method for manufacturing a honeycomb structure according to any one of claims 3, 6, and 7, wherein the nonwoven fabric member is a polyester nonwoven fabric member containing polyester fibers. The method for manufacturing a honeycomb structured body according to claim 3, wherein the porous resin layer is made of at least one selected from a fluororesin and polypropylene. The method for manufacturing a honeycomb structure according to any one of claims 1 to 12, wherein the mold is separable into a plurality of members, and in the fixing step, the plurality of members are used in combination. The method for manufacturing a honeycomb structured body according to any one of claims 1 to 13, wherein in the fixing step, a plurality of the honeycomb fired bodies are fixed by further using an interval holding member that holds the honeycomb fired bodies at regular intervals. The method for manufacturing a honeycomb structured body according to any one of claims 1 to 13, wherein in the fixing step, the honeycomb fired body is fixed by holding both end faces of the honeycomb fired body. In the drying step, the sealing material paste is used so that the presence ratio of the inorganic particles and the presence ratio of the inorganic fibers are substantially the same on the surface side of the coat layer and the ceramic block side of the coat layer, respectively. The method for manufacturing a honeycomb structure according to any one of claims 1 to 15, wherein the honeycomb structure is dried and solidified. A honeycomb structured body in which a columnar honeycomb fired body in which a large number of cells are arranged in parallel in the longitudinal direction across a cell wall is provided with a coating layer around a ceramic block in which a plurality of cells are bound through an adhesive layer. There,
The adhesive layer and the coat layer include inorganic particles and / or inorganic fibers,
The adhesive layer and the coat layer are integrally formed, there is no boundary surface that separates both,
The ratio of inorganic particles and inorganic fibers is
A honeycomb structure, wherein the surface side of the coat layer and the ceramic block side of the coat layer are substantially the same.

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