KR101403157B1 - Method for producing ceramic honeycomb structure - Google Patents

Abstract

The present invention relates to a method for producing a ceramic honeycomb structure comprising a ceramic porous body having a plurality of pores and having a plurality of cells divided by barrier ribs and forming a fluid flow path, Kneading the mixture to obtain clay; Preparing a mold having a plurality of combustible rods arranged at regular intervals; A step of molding a ceramic formed body in which a plurality of combustible rods are embedded by injecting clay made of the molding material into the molding mold; A step of drying the ceramic formed body to obtain a ceramic dried body; And forming a ceramic honeycomb structure having a plurality of cells partitioned by a plurality of partition walls by burning the combustible rod buried in the ceramic dried body, together with firing the ceramic dried body.

Description

METHOD FOR PRODUCING CERAMIC HONEYCOMB STRUCTURE [0002]

The present invention relates to a method of manufacturing a ceramic honeycomb structure used as a purification device for automobile exhaust gas, a filter for preventing industrial pollution, and the like, and more particularly to a method for manufacturing a ceramic honeycomb structure using a ceramic porous body having a plurality of pores, The present invention relates to a method of manufacturing a ceramic honeycomb structure having a plurality of cells divided into fluid channels.

[National R & D Project Supporting the Invention]

Assignment number: 2010201010109C-22-1-000

Department name: Ministry of Knowledge Economy

Research Project: Greenhouse Gas Treatment Technology Development Project

Title: Simultaneous reduction catalyst and process development of N2O / NOx with stationary source by using single reducing agent

Organized by: Korea Institute of Energy Research

Project leader: Moon Seung-hyun

Research period: 2010.10.01-2012.09.30

Generally, a honeycomb structure is formed in a honeycomb or lattice shape and is applied in various technical fields. For example, a honeycomb structure formed from a ceramic material is used as a catalyst carrier in a catalytic converter of an exhaust portion of an internal combustion engine and is also used for a radiator filter, a fine filter of a diesel engine, a molten metal filter, a wood combustor substrate, and a heat exchanger.

The honeycomb structure has a truss structure with high purification efficiency and dynamically stable structure because it has a large effective area in the same volume and large contact area with harmful gas or wastewater and waste oil.

Such a honeycomb structural body is mainly made of a metal material and a ceramic material, and a honeycomb structural body made of a metal is mainly made of aluminum or a thin steel plate to form a honeycomb structure by welding or mechanical joining .

A honeycomb structural body made of a metal material may be formed by a corrugated sheet composed of several layers or a metal support composed of a corrugated sheet and a flat sheet and a casing surrounded by the metal support and joined to the metal support by welding or the like, And is used in a purification apparatus, particularly an exhaust gas purification apparatus for a vehicle engine.

The production of the honeycomb structure using the ceramic material is mainly made of aluminum oxide, zirconium and cordierite zeolite, and the honeycomb structure is formed through the extrusion process by the extrusion die system. Ceramics or ceramics are easy to mold, have excellent heat resistance, and are porous, thus having a surface area larger than that of a honeycomb structure of a metal material.

Such a ceramic honeycomb structure is obtained by adding a processing aid such as a pore-forming agent or a binder to a powder of ceramics, kneading the same, shaping it into a predetermined shape, and then firing it. At this time, the pore-forming agent is generally used to increase the number of pores in the ceramic porous body or to control the size and amount of the pores.

In a general method for manufacturing a ceramic honeycomb structure, an extrusion paste is prepared by first mixing and melting a ceramic material, a forming binder, a sintered binder, and a sintered binder in an appropriate solvent. In this case, the plastic binder to be added is added in order to impart a plastic flow so that the face smoothly passes through a complicated extrusion die, which will be described later, during extrusion molding. The molding binder is crushed to maintain the shape of the honeycomb structure until the formed body is sintered after extrusion. . The paste thus prepared is made into a honeycomb structure having cells or cells of a desired shape through an extrusion process using a complicated extrusion mold.

FIG. 2 shows a schematic shape of a typical ceramic honeycomb structure 10. A conventional ceramic honeycomb structure 10 is manufactured by extruding a ceramic honeycomb structure into a honeycomb structure by passing a ceramic paste through a chamber of an extrusion molding machine and passing through an extrusion mold of the honeycomb structure. The extruded ceramic honeycomb formed body is subjected to a drying process before sintering. After the ceramic honeycomb formed body is sintered to impart mechanical and thermal strength to the structure using thermal energy, the ceramic honeycomb structural body 10 is made . That is, a method of manufacturing a ceramic honeycomb structure according to the related art is mainly a method of extruding the prepared clay using an extrusion molding having a shape complementary to a desired honeycomb structure (cell shape, partition wall thickness, cell density, etc.) do.

However, such a conventional method for manufacturing a ceramic honeycomb structure requires a complicated extrusion die for extrusion, which requires a high production cost and a high manufacturing technique. Also, the mold is worn out during the extrusion process to shorten the life of the mold, and the shape and size of the cell are limited due to difficulty in manufacturing the extrusion mold.

In order to use the ceramic honeycomb structure as a carrier of the catalyst, a catalyst layer is coated on the partition wall by a method called 'wash coating'. In order to form the catalyst layer, a ceramic honeycomb formed body or a ceramic honeycomb structure 10 A process of immersing the catalyst in a slurry state is required.

Therefore, the conventional method of manufacturing a ceramic honeycomb structure has been disadvantageous in that it is suitable for mass production of small and identical products, but is not suitable for producing ceramic honeycomb structures having various shapes and sizes.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a ceramic molded body having a predetermined shape, a plurality of combustible rods embedded in the ceramic molded body, A combustible rod buried in the ceramic formed body is burnt and removed to thereby form a cell acting as a fluid flow path in the place where the combustible rod is located. Thus, a ceramic honeycomb of various sizes and shapes The present invention provides a method for manufacturing a ceramic honeycomb structure which can easily produce a structure.

The present invention also provides a method for forming a catalyst layer on a peripheral surface of a plurality of combustible rods buried in a ceramic formed body and forming a catalyst layer on a partition wall partitioning the cells of the ceramic honeycomb structure, And a method for manufacturing the ceramic honeycomb structure.

The present invention also provides a method for providing a ceramic honeycomb structure having cells of various shapes, sizes, and shapes and sizes using various shapes of a molding frame and a combustible rod.

As a means for achieving the object of the present invention, the method for manufacturing a ceramic honeycomb structure according to the present invention comprises:

Kneading a molding material including a ceramic raw material and a processing aid to obtain clay;

Preparing a mold for arranging a plurality of flammable rods at regular intervals and forming a certain type of ceramic molded body;

Molding a ceramic formed body in which a plurality of combustible rods are embedded by injecting clay made of the molding material into the molding mold;

A step of drying the ceramic formed body to obtain a ceramic dried body;

And forming a ceramic honeycomb structure having a plurality of cells partitioned by a plurality of partition walls by burning the combustible rod buried in the ceramic dried body, together with firing the ceramic dried body.

In the present invention, the forming die may include a side plate that forms an outer surface of the ceramic formed body, an upper plate that forms one end surface of the ceramic formed body, a lower plate that forms the other end surface, And a plurality of combustible rods extending through the end face.

The combustible rod is a rod having a cross-sectional shape of a quadrangle, a circle, and an ellipse, and is arranged at regular intervals on the lower plate. The combustible rod passes through a through hole formed in the upper plate and is coupled to the upper plate.

The forming step includes molding the ceramic molded body in which a plurality of flammable rods are embedded in the ceramic molded body so that the upper portion of the combustible rod passes through the through holes of the upper plate by injecting the prepared clay into the molding mold .

The firing process burns the ceramic formed body and burns the combustible rod to remove the combustible rod in the form of powder, thereby forming a plurality of cells partitioned by the partition walls in the place where the combustible rod is located.

Further, a catalyst coating layer containing a noble metal of Pt, Pd, and Rh and at least one of common metals such as Fe and Cu is formed on the outer peripheral surface of the combustible rod, and the combustible rod having the catalyst coating layer is formed through the molding process The catalyst coat layer is buried in the ceramic formed body to transfer the catalyst coat layer into the ceramics formed body, and the combustible rod is burnt and removed in the firing step to form a catalyst layer on the partition wall.

According to the method for manufacturing a ceramic honeycomb structure of the present invention, since the extrusion die having a complicated structure is not used, a ceramic honeycomb structure having various sizes and shapes can be easily manufactured while solving the difficulties associated with the production of extrusion dies.

In addition, the present invention can easily form a catalyst layer without the same process as a separate wash coating process by transferring a catalyst coated on a combustible rod to a ceramic formed body to form a catalyst layer when the ceramic formed body is molded.

The present invention can produce a ceramic honeycomb structure having various sizes and shapes using a simple forming mold, and thus can be suitably applied to small-quantity production of various types.

1 is a flow chart showing a method of manufacturing a ceramic honeycomb structure according to the present invention,
2 is a perspective view showing an example of a ceramic honeycomb structure according to the present invention,
3 is a perspective view showing a ceramic formed body in which a combustible rod is embedded for manufacturing a ceramic honeycomb structure according to the present invention,
4 to 6 are a perspective view and a sectional view showing an example of a molding die for molding a ceramic formed body according to the present invention,
7 to 9 are sectional views showing a press apparatus for molding a ceramic formed body according to the present invention and its operation,
10 is a sectional view showing a ceramic formed body manufactured according to the present invention,
11 and 12 are schematic cross-sectional views showing a process of firing a ceramic formed body according to the present invention,
13 is a perspective view showing an example of a combustible rod for forming a catalyst layer in a ceramic formed body according to the present invention,
14 is a sectional view showing a process of forming a catalyst layer in a ceramic formed body according to the present invention,
15 is an enlarged view showing a ceramic honeycomb structure in which a catalyst layer is formed according to the present invention.

Hereinafter, a method of manufacturing a ceramic honeycomb structure according to the present invention will be described in detail with reference to the accompanying drawings.

1, a method of manufacturing a ceramic honeycomb structure according to the present invention includes a step (S10) of kneading a molding material including a ceramic raw material and a processing aid to obtain a clay (hereinafter referred to as a clay preparing process) A step (S20) of preparing a forming mold for forming a plurality of combustible rods at regular intervals and molding a ceramic formed body having a predetermined shape (hereinafter referred to as a forming mold preparing step), a step of injecting the molding material composed of the molding material into the molding mold (Hereinafter referred to as a forming step) (S30) of forming a ceramic molded body in which a plurality of combustible rods are embedded (S30), a step (S40) of drying the ceramic formed body to obtain a ceramic dried body The ceramic dried body is fired and the combustible rod buried in the ceramic dried body is burned to be partitioned by a plurality of partition walls and extended parallel to each other (Hereinafter referred to as a firing step) a step of forming a ceramic honeycomb structure having a plurality of cells comprise the (S50) ..

2 shows an example of a ceramic honeycomb structure 10 manufactured according to the present invention. As shown in the figure, the ceramic honeycomb structure 10 of the present invention is generally composed of an outer surface 12, one side surface 13, and the other side surface 13 formed on the opposite side so as to correspond to the one side surface 13 And has a side surface 15. A plurality of cells 11 are formed in parallel in the ceramic honeycomb structure 10. The cell 11 is formed by a partition wall 14 and extends from the one end face 13 to the other end face 15. The sectional shape of the ceramic honeycomb structure 1 according to the present invention is not particularly limited and may be, for example, a polygonal shape such as a quadrangle, a circle, an ellipse, a racetrack, a rectangle, a triangle, .

Next, FIG. 3 shows an example of the ceramic formed body 20 manufactured according to the present invention. As shown in the figure, the ceramic formed body 20 of the present invention has an outer surface 22, a one end surface 23 formed on the opposite side so as to correspond to the one end surface 23 and the one end surface 23, Respectively. A plurality of combustible rods 51 are formed in parallel in the ceramic honeycomb structure 10. The combustible rods 51 are spaced apart at regular intervals and extend from the one end surface 23 to the other end surface 25. At this time, the plurality of combustible rods 51 may be parallel but generally not parallel. The cross-sectional shape of the ceramic formed body 20 according to the present invention is not particularly limited and may be a polygonal shape or a deformed shape such as a quadrangle, a circle, an ellipse, a race track, a rectangle, a triangle, have

As described above, in the method of manufacturing a ceramic honeycomb structure according to the present invention, in the step of forming the ceramic formed body 20, a plurality of combustible rods 51 are embedded in the ceramic formed body 20, The ceramic honeycomb structural body 10 having the plurality of cells 11 is manufactured by burning and removing the combustible rod 51 in the process of firing the buried ceramic molded body 20. [ That is, the present invention is characterized in that the ceramic formed body 20 is formed using a molding die having a simple structure, and then a cell is formed in a sintering process.

Referring again to FIG. 1, a method of manufacturing the ceramic honeycomb structure of the present invention will be described in detail. First, the clay-making step (S10) is a step of kneading a molding material containing a ceramic raw material to obtain clay. The ceramic raw material is not particularly limited as long as it is a ceramics capable of forming a predetermined shape by firing or a material made of ceramics having a predetermined shape by firing. Examples thereof include cordelite raw material, zeolite, mullite, alumina, aluminum titanate, lithium aluminum Silicate, spinel, silicon carbide, metal silicon, silicon nitride, or the like can be used.

From the viewpoint of thermal shock resistance, it is preferable to use a cordelite raw material as a main component. Here, the cordelite forming raw material means a raw material capable of forming cordelite by itself and / or firing, and the raw material capable of forming cordelite by firing is 42 to 56 mass% of SiO _2, refers to include, for example talc, kaolin, presintering kaolin, alumina, aluminum hydroxide, silica, to provide a chemical composition of 30 to 45% by weight of Al ₂ O _3, 12~16% by weight MgO in a predetermined ratio. In addition, the main component means 50 mass% or more, preferably 70 mass% or more, and more preferably 80 mass% or more of the ceramic raw material.

From the viewpoint of heat resistance, it is preferable to use silicon carbide or silicon carbide and metal silicon as main components. In the case where the ceramic raw material is mainly composed of silicon metal (Si) and silicon carbide (SiC), if the Si content defined by Si / (Si + SiC) is too small, the effect of Si addition is difficult to obtain and 50 mass% It is difficult to obtain the effect of heat resistance and high thermal conductivity, which is characteristic of SiC. The Si content is preferably 5 to 50 mass%, more preferably 10 to 40 mass%.

In addition to the aggregate particles and water, the clay may contain other additives such as an organic binder, a dispersant, and an inorganic binder, if necessary. The organic binder is an additive which functions as a reinforcing agent in the form of a gel in the formed body (clay) before baking and maintains the mechanical strength of the formed body. Therefore, as the organic binder, an organic polymer capable of gelling in a molded body (clay) such as hydroxypropyl methylcellulose, methylcellulose, hydroxyethylcellulose, carboxylmethylcellulose, polyvinyl alcohol and the like can be suitably used .

The dispersant is an additive for promoting dispersion of the aggregate particles in water, which is a dispersion medium of the aggregate particles. As the dispersing agent, for example, ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like can be used. The inorganic binder is an additive for reinforcing the bonding between the aggregate particles, and at least one selected from the group consisting of alumina, silica, zirconia, titania, glass frit, feldspar, cordierite having an average particle diameter of 10 탆 or less can be used have. The inorganic binder is preferably added in an amount of 10 to 35 parts by mass based on 100 parts by mass of the aggregate particles. If the amount is less than 10 parts by mass, the strength of the base material is lowered. If the amount exceeds 35 parts by mass, the strength is improved. However, since the inorganic binder remains in the gap of the aggregate particles, Which is undesirable.

Further, the clay may further include a pore-forming agent. The pore-forming agent has a function of forming a ceramic porous body, and a porous ceramic body having excellent dimensional accuracy can be produced by using a mixture of starch or a foamed resin finished with foaming and starch. That is, 1 to 30 parts by weight of powdered starch, a binder and water are mixed and kneaded with 100 parts by weight of a ceramic raw material which becomes cordierite by firing, followed by extrusion molding and drying and firing to obtain a cordierite ceramic honeycomb structural body . At this time, there is no particular limitation on the amount of the starch to be added, but if it is excessively large, the amount of heat generated by combustion of the starch in the firing step becomes too large to cause cracks in the porous ceramic body, which is not preferable. On the other hand, if the amount of the starch added is too small, it is difficult to obtain sufficient effect of pore action, which is not preferable. The amount of the starch to be added is preferably 1 to 30 parts by mass, more preferably 5 to 20 parts by mass, per 100 parts by mass of the ceramic raw material.

The molding material, aggregate particles, water, organic binder and the like can be prepared by mixing with, for example, a vacuum pouring machine or the like and kneading the mixture into a clay having an appropriate viscosity. In the clay-making step (S10), a method of kneading the molding material is not particularly limited, and kneaders such as a kneader, a pressure kneader, a single-axis continuous extruder, a biaxial continuous kneader extruder, have. The clay can be prepared by kneading the molding material with the kneader, but if the kneaded clay kneaded with a kneader not accompanied by a vacuum process such as a general kneader or a press kneader is kneaded again by using a vacuum kneader or the like, It is possible to prepare clay with little or no clay, which is preferable since the plasticity is improved.

Next, in a step S20 of preparing the mold, a mold 50 having a plurality of combustible rods 51 arranged at regular intervals is prepared. The forming mold 50 is formed by injecting and pressurizing the ceramic clay to form the ceramic formed body 20. 4 to 6 show an example of the mold 50 according to the present invention. As shown in the figure, the forming die 50 includes a plurality of side plates 52 forming the outer surface 22 of the ceramic formed body 20 and a plurality of side plates 52 forming the one end side surface 23 of the ceramic formed body 20 A lower plate 53 which forms the other end face 25 of the ceramic formed body 20 and a plurality of flammable and heatable portions 53 which penetrate through the one end face 23 and the other end face 25, And a rod (51).

The combustible rod 51 is a rod having various cross-sectional shapes such as a quadrangle, a circle, and an ellipse, and is arranged at regular intervals on the lower plate 53. Preferably, the lower plate 55 is formed with a plurality of insertion grooves 56 into which a lower end of the combustible rod 51 is inserted at a predetermined length. The upper end of the combustible rod 51 passes through the upper plate 55 and a plurality of through holes 57 through which the upper end of the combustible rod 51 passes are formed at regular intervals in the upper plate 55.

The combustible rods 51 are buried in the ceramic formed body 20 and burned and removed in a process of firing. For this purpose, the combustible rod 51 is made of a material which retains the shape of the rod at the firing temperature of the ceramic formed body 20, and has characteristics of burning and changing into powder at a firing temperature of the ceramic formed body 20 or higher. For example, wood remains in the form of a rod at temperatures below 150 ° C, but burns above 200 ° C, leaving only ashes. Therefore, the combustible rod 51 made of wood retains the shape of the rod in the molding and drying process, but is burned in the predetermined process, and the cell 11 is formed in the place where the combustible rod 51 was located.

In addition, carbon maintains a solid state at 1000 캜 or lower, but ignites at 1000 캜 or higher and burns. Heat-resistant adhesives such as epoxy, phenol resin, silicone, polybenzimidazole, polyamide, polybenzimidazole, etc., do not melt or burn at 200 ° C or lower, but ignite and burn at 600 ° C or lower. Therefore, the combustible rod 51 formed by extruding the mixture of the carbon powder and the adhesive properly maintains the shape of the rod at a temperature of 600 ° C or lower. However, when the adhesive is burned at 600 ° C or higher, the rod- The carbon powder is burned and disappears, so that the cell 11 is formed at the place where the combustible rod 51 is located.

Next, in the molding step (S30), ceramic clay is injected into the prepared mold 50 and pressed to form the ceramic molded body 20 in which the combustible rod 51 is embedded. At this time, the side plate 52 of the forming die 50 is firmly fixed by clamping means (not shown). A pressing apparatus or a vibration apparatus may be used to press the clay injected into the forming mold 50. [

7 to 8 show an example of the press apparatus 60 that can be applied to the molding step S30. The press apparatus 60 includes a base 63 on which the mold 50 is mounted and a plurality of supports 62 for pressing and supporting the side plate 52 of the mold 50 from front to back, And a pressing plate 65 for pressing the upper plate 56 of the pressing plate 50 downward. At this time, the pressing plate 61 and the pressing plate 65 can be vertically moved along the hydraulic cylinder or the screw shaft. A plurality of pressing pins 67 having a predetermined length are formed on the bottom surface of the pressing plate 65 so as to receive the flammable rod 51 passing through the through hole 57 formed in the upper plate 55, They are spaced apart at regular intervals. Therefore, the front end of the pressing pin 67 can press the top plate 55 without colliding with the flammable rod 51. At this time, a tapered tapered portion 59 is formed at the upper end of the combustible rod 51 so that the combustible rod 51 can be smoothly inserted into the through hole 57 of the upper plate.

When a certain amount of ceramic clay is injected into the forming die 50 and the plurality of supporting stands 62 are moved to support the side plate 52 and the pressing plate 65 is lowered to press the upper plate 56, The ceramic formed body 20 is formed according to the shape of the forming die 50. A plurality of combustible rods 51 are integrally embedded in the ceramic compact 20. 9 shows a mold 50 in which the ceramic formed body 20 is molded. Accordingly, when the mold 50 is removed, a ceramic molding frame 20 in which a plurality of combustible rods 51 are integrally embedded can be obtained as shown in FIG.

As described above, the method for manufacturing a ceramic honeycomb structure according to the present invention comprises the steps of: burying the combustible rod 51 in the ceramic molding body 20 in the step of molding the ceramic molding body 20, and firing the ceramic molding body 20; The plurality of cells 11 are formed in the ceramic formed body 20 by the partition walls 14 to form fluid flow paths.

Therefore, the manufacturing method of the ceramic honeycomb structure according to the present invention does not use a complicated and expensive extrusion die, thereby reducing manufacturing cost. That is, in the related art, since an extrusion die having a plurality of through holes is required to be manufactured, a costly and high-level mold manufacturing technique is required. In addition, in order to provide ceramic molded bodies of various shapes and sizes, extrusion molds of various shapes and sizes must be prepared, and thus not only the initial investment cost is high, but also the mold is worn out. Further, the shape of the cell is limited to a square, a triangle, a hexagon, etc. due to the difficulty of manufacturing an extrusion mold, and the corner portion of such a shape causes a stress concentration, resulting in a problem of a mechanical strength being lowered. Further, when molding is performed using an extrusion molding machine having a complicated structure, ceramic clay remains in the molding machine, and ceramic clay is wasted.

In the ceramic honeycomb structure according to the related art, a ceramic honeycomb segment is manufactured using a limited extrusion mold, and the ceramic honeycomb segment is laminated to a desired shape and size, and bonded together with a bonding material to obtain a ceramic honeycomb structure 10. However, this method has a problem in that a process of assembling and joining ceramic honeycomb segments is added, as well as a stress is generated in a bonding material portion in a predetermined process and a crack is easily formed. However, since the present invention is made of a molding frame 50 made of wood or the like, which is easy to manufacture, and a combustible material, it is inexpensive and easy to manufacture in various shapes and sizes.

Then, the ceramic formed body 20 obtained in the forming step S30 is dried in the drying step. The drying step (S40) is performed to remove moisture, liquid medium, and the like contained in the ceramic formed body (20). The drying method is not particularly limited, and generally, hot air drying, microwave drying, dielectric drying, vacuum drying, vacuum drying and the like can be carried out. Among them, hot air drying and hot air drying It is preferable to carry out drying in a drying step in which microwave drying or dielectric drying is combined. The drying temperature of hot air drying is preferably in the range of 80 to 150 占 폚 in that it can be dried quickly.

Then, the ceramic formed body 20 obtained in the drying step (S40) is fired in the firing step (S40) to obtain the ceramic honeycomb structure 10. The firing is an operation for securing a predetermined strength by densifying the aggregate particles in the honeycomb formed body by sintering. 11, the ceramic formed body 20 according to the present invention is placed in a kiln 80 provided with a perforated plate 81 and heated. The firing conditions (temperature and time) may be suitably selected depending on the kind of the aggregate particles to be used. For example, when silicon carbide is used as the aggregate particles, it is preferable to perform calcination at a temperature of 1300 to 2300 캜 for about 1 to 5 hours. The firing temperature and the firing atmosphere of the ceramic dried body 40 vary depending on the ceramic raw material, and those skilled in the art can select an appropriate firing temperature and firing atmosphere for the selected ceramic raw material.

For example, an oxide-based material such as a cordierite-forming raw material, mullite, etc. is preferably fired in an atmospheric environment. In the case of a cordelite-forming raw material, firing is preferably performed at a temperature of 1400 to 1440 ° C. Further, it is preferable that the non-oxide material such as silicon carbide, silicon nitride and the like is fired in a non-oxidizing atmosphere such as nitrogen or argon. When the silicon carbide is bonded to the metal silicon, it is preferable to sinter at 1400 to 1800 ° C. When silicon carbide is bonded with silicon nitride or the like, it is preferable to carry out sintering at a temperature of 1550 to 1800 ° C. When the silicon carbide particles are bonded to each other by the recrystallization method, it is necessary to perform calcination at a temperature of at least 1800 占 폚 or more. Further, in order to produce silicon nitride by firing the metal silicon in a nitrogen atmosphere, it is preferable to perform firing at a temperature of 1200 to 1600 캜.

On the other hand, the calcination step of burning and removing the combustible rod 51 in the honeycomb formed body before or before the calcination can be further performed. It is preferable in that the removal of the combustible rod 51 can be promoted in the calcining step. For example, the ceramic formed body 20 may be heated at a temperature not higher than the firing temperature for a certain period of time to remove volatile components from the fired rod 51. However, the firing temperature may be about 200 to 1000 ° C., , Usually about 1 to 10 hours.

Thus, in the sintering process (S50) according to the present invention, the combustible rod 51 is burned and removed. 12, the combustible rod 51 buried in the ceramic formed body 20 is ignited at the firing temperature of the ceramic formed body 20 and becomes a sputtered state, and is removed under the porous plate 81 by gravity . A cell 11 corresponding to the shape of the combustible rod 51 is formed in the place where the combustible rod 51 is located.

In the firing step (S50), a pore forming agent composed of starch or a mixture of starch and foamed resin is burned to form a porous ceramic body. The ceramic honeycomb structure produced by the present invention has pores in the ceramic body. The porosity and the pore diameter are not particularly limited, and appropriate pore diameter and porosity can be selected according to the application. For example, when used in a DPF (diesel particulate filter), a preferable porosity is in the range of 30 to 90%. If the porosity is less than 30%, the pressure loss is too large, and if it exceeds 90%, the strength as a ceramic body is insufficient.

The ceramic honeycomb structure 10 manufactured by the present invention is not particularly limited in the thickness of the partition wall. However, if the partition wall is too thick, the pressure loss when the fluid to be treated permeates the porous partition wall becomes large. If the partition wall is too thin, Each is not preferable. The thickness of the barrier rib is preferably in the range of 30 to 2000 占 퐉, more preferably in the range of 40 to 1000 占 퐉, and most preferably in the range of 50 to 500 占 퐉. The cell density (the number of the through holes per unit end surface area) is not particularly limited. However, if the cell density is too small, the strength and the effective GSA (geometrical surface area) as honeycomb structural bodies are insufficient. If the cell density is too large, The pressure loss when the processing fluid flows becomes large. The cell density is preferably 6 to 2000 cells / square inch (0.9 to 311 cells / cm2), more preferably 50 to 1000 cells / square inch (7.8 to 155 cells / cm2), most preferably 100 to 400 cells / Square inch (15.5 to 62.0 cells / cm < 2 >). The cross-sectional shape of the cell is not particularly limited, but from the viewpoint of production, it is preferable to use any one of triangular, rectangular, hexagonal, and corrugated shapes. Further, in the case of the DPF in which the flow holes of the end faces of the honeycomb structural body are alternately sealed, a triangle or a quadrangle is particularly preferable in view of the filter area.

When the ceramic honeycomb structure manufactured by the present invention is to be used as a catalyst carrier for purifying exhaust gas or modifying a liquid fuel or a gaseous fuel in a combustion apparatus such as a heat engine such as an internal combustion engine or a boiler A catalyst layer 18 including a noble metal or a common metal having a catalytic function, for example, is formed on the wall 14 of the ceramic honeycomb structure 10. In the conventional method of forming the catalyst layer 18, a catalyst layer can be formed by wash-coating a catalyst slurry on a porous ceramic body, followed by drying and firing. Representative examples of metals having catalytic activity include noble metals such as Pt, Pd and Rh and common metals such as Fe and Cu, and it is preferable to carry at least one of them.

In the present invention, a catalyst layer can be formed without a separate coating process by forming a catalyst layer 18 on a partition wall partitioning the cells 11 by using a plurality of combustible rods 51 embedded in the ceramic formed body 20 have. A double oxide containing at least one noble metal selected from the group consisting of platinum, lanthanum, nickel, cobalt, magnesium and palladium, and at least one metal selected from the group consisting of Fe, Cu and common metals . In addition, the catalyst layer may consist of a first separated layer and a second separated layer overlapped on the lower layer. The catalyst layer 18 includes ceramics or ceramics constituting the ceramic formed body 20.

Therefore, when the ceramic molded body 20 is molded using the combustible rod 51 having the catalyst coat layer 58 formed thereon according to the present invention, as shown in FIGS. 13 to 15, the catalyst coat layer 51 of the combustible rod 51 58 are transferred to the ceramic formed body 20 in the forming process S30 to form a catalyst coat layer 28. The transferred catalyst coat layer 28 is sintered in a sintering process S50 to form a catalyst layer 18 are formed. As described above, according to the present invention, since the cell 11 of the ceramic formed body 20 can be formed using the combustible rod 51 and the catalyst layer 18 can be formed on the partition wall 14, Can be omitted.

Further, when the ceramic honeycomb structure manufactured according to the present invention is used for a filter such as a diesel particulate filter (hereinafter referred to as DPF), the opening of the predetermined cell of the cell 11, And the remaining cells 11 are sealed at the other end face 15 of the opening portion. The treatment fluid flows into the cell 11 which is opened at the one end portion 13 and passes through the porous partition 15 to the other end portion 15, and at this time, the partition wall 14 becomes a filter, and a large filtration area can be ensured. The sealing of such a cell can be performed by masking the non-sealed flow holes and providing the raw material used for sealing to the opening end face of the ceramic honeycomb structure in a slurry form, followed by drying and firing.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It is to be understood that both the technical idea and the technical spirit of the invention are included in the scope of the present invention.

10: Ceramic honeycomb structure 11:
12: outer surface 13, 15: end face
14: partition wall 18: catalyst layer
20: ceramic formed body 22: outer surface
23, 25: end face 28: catalyst layer
50: Molding frame 51: Flammable rod
52: side plate 53: bottom plate
54: lower plate block 54: lower plate block
56: upper plate 57: through hole
58: catalyst coating layer 59: taper
60: Press apparatus 62: Support
63: base 65: pressure plate
80: kiln

Claims (6)

Kneading a molding material including a ceramic raw material and a processing aid to obtain clay;
A side plate that forms an outer surface of the ceramic formed body to form a certain shaped ceramic formed body; an upper plate that forms one end surface of the ceramic formed body; a lower plate that forms the other end surface; Preparing a molding frame including a plurality of combustible rods extending through the end face and having a catalyst coat layer formed on the outer circumferential surface thereof, the catalyst coat layer including a noble metal of Pt, Pd and Rh and at least one of common metals such as Fe and Cu; and;
Molding a ceramic formed body in which a plurality of flammable rods are embedded in a ceramic formed body by injecting clay made of the molding material into the forming mold and pressing the upper plate to penetrate the upper end of the combustible rod through the through holes of the upper plate; ;
Drying the ceramic formed body to transfer the catalyst coat layer of the combustible rod to the inside of the ceramic formed body to obtain a ceramic dried body;
A plurality of cells partitioned by a plurality of barrier ribs are formed by burning a combustible rod embedded in the ceramic dried body, and a catalyst layer is formed on the barrier ribs. [7] The ceramic honeycomb structure according to claim 1, ≪ / RTI >
delete The method according to claim 1,
Wherein the combustible rod is a rod having a rectangular, circular, or elliptical cross-sectional shape and arranged at regular intervals on the lower plate, and is coupled to the upper plate through a through hole formed in the upper plate. delete delete delete

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