JP3121497B2 - Ceramic structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic structure and, more particularly, to a ceramic honeycomb structure, a monolith structure, and a ceramic formed by piercing a plurality of through-holes in a longitudinal direction of other members. A new structure of the structure is proposed.

[0002]

2. Description of the Related Art In general, a ceramic honeycomb structure having a plurality of through-holes arranged in parallel along a longitudinal direction is used as a filter for purifying exhaust gas for vehicles and exhaust gas from factories. It is used. In this ceramic structure, the open-sealed state of the through-hole at the end face thereof has a checkered pattern (a state in which the open-sealed state is such that adjacent through-holes are different from each other). . That is, only one end face of these through-holes is plugged, and adjacent through-holes are opened or closed differently from each other to form a checkerboard-shaped plugging. Therefore, if one end face of one through hole is open, the other end face is closed. On the other hand, the adjacent through hole has one end face closed and the other end face open. When the gas to be treated flows from one end face of each of the through holes, the ceramic structure passes through the porous partition wall on the way to the other end, enters the adjacent through hole, and enters the other end face. The treated gas is allowed to flow out of the tank. It should be noted that the ceramic structure is a porous body, so that it is possible to ventilate each other through the partition wall separating each through-hole and easily enter another through-hole in the structure. Due to this, different gas flows through the through holes on the gas inlet side and the gas inlet side. When the exhaust gas is passed through such a ceramic structure, the exhaust gas flowing from one end face as described above passes through the partition wall toward the outlet, and the particulate matter (particulate matter) in the exhaust gas is discharged. ) Is trapped and purified by the partition. In addition, the particulates are collected and deposited particularly on the partition wall on the inflow port side with the purifying action of the exhaust gas, so that the particulates are gradually clogged and the ventilation is hindered. For this reason, the ceramic structure needs to be periodically subjected to a treatment (hereinafter, simply referred to as “regeneration”) for burning and removing particulates deposited on the partition walls that cause clogging by a heating means such as a burner or a heater.

However, in the above-mentioned ceramic structure, in such a regeneration, a non-uniform heating process, local heat generation due to abnormal burning of the particulates, and a thermal shock caused by a rapid temperature change of the exhaust gas cause the internal structure of the ceramic structure. A non-uniform temperature distribution occurs and thermal stress acts. As a result, the ceramic structure causes cracks and erosion,
As a result, there is a problem that the destruction is hindered and the collection of the particulates is hindered.

On the other hand, conventionally, as a means for solving the above problem, for example, a ceramic structure is divided into a plurality of ceramic members by a plane perpendicular to the axis or a plane parallel to the axis. A method for reducing the thermal stress acting on a ceramic structure has been proposed (Japanese Patent Application Laid-Open No. 60-1985).
-65219). Further, the sealing property of the exhaust gas is improved by inserting a non-adhesive sealing material into a gap generated between the ceramic members of the divided ceramic structure (hereinafter, referred to as a “divided ceramic structure”). A divided ceramic structure has been proposed (see Japanese Utility Model Laid-Open No. 1-63715).

According to the above proposals, the divided ceramic structure can release the thermal stress as seen in the integrated ceramic structure by employing the sealing material. However, since the sealing material is non-adhesive, the ceramic members cannot be firmly joined. For this reason, the split ceramic structure according to the above-described related art requires a binding force for binding the ceramic members and maintaining the form as one structure. Conventionally, as means for imparting this restraining force, a heat-expandable heat insulating material is provided on the outermost peripheral portion, or a heat-expandable heat insulating material is applied as an internal sealing material.

However, the above-mentioned non-adhesive sealing material and thermally expandable heat insulating material have low durability against heat at the time of regeneration and repetition of vibration generated from the internal combustion engine.
The sealing material has a problem that the sealing property is deteriorated due to the volume contraction and the deterioration of the strength, and the thermal expansion heat insulating material has a problem that the restoring force after the volume expansion is rapidly reduced. Therefore, the divided ceramic structure loses the force of supporting the plurality of ceramic members constituting the divided ceramic structure, and may be decomposed and scattered by the pressure of the exhaust gas. Moreover, even if a reinforcing member is provided on the end face on the gas outlet side, it is difficult to prevent the deterioration of the sealing material, and improvement of durability has been desired.

[0007] In particular, in order to form a large divided ceramic structure, a larger restraining force is required, and a combination of a conventional non-adhesive sealing material and a heat-expandable heat insulating material cannot be used from the initial stage. However, a product that can withstand practical use has not been obtained.

In view of such circumstances, the present inventors have first improved the sealing material constituting the divided ceramic structure by using ceramic fibers, silicon carbide, and the like as means for overcoming the above-mentioned problems of the prior art. An "exhaust gas purification apparatus and its components" using a sealing material composed of powder and an inorganic binder has been proposed (see Japanese Patent Application No. 5-204242). According to this proposal, the durability of the divided ceramic structure can be improved to some extent because the seal member connects the plurality of ceramic members to each other.

[0009]

However, when the sealing material is filled between the ceramic members and hardened, the sealing material is liable to cause migration (a phenomenon in which a binder moves as the solvent is dried and removed). there were. Therefore, the sealing layer formed by curing the sealing material becomes brittle. In other words, the inorganic binder constituting the sealing material tightly joins the ceramic member and the sealing layer, and the three-dimensionally interwoven ceramic fiber which is an important element for the expression of the stress buffering function of the sealing layer. It has the effect of joining intersections.
However, the inorganic binder migrates from the inside of the seal layer to the bonding surface with the ceramic member due to migration occurring during the process of drying and curing, and the bonding force at the intersection is reduced, which in turn causes a reduction in the strength of the ceramic structure itself. Therefore, the desired durability could not be satisfied. In addition, the silicon carbide powder constituting the sealing material similarly moves with the migration, causing a decrease in thermal conductivity and unevenness, and a reduction in the regeneration efficiency of the ceramic structure.

[0010] On the other hand, a method of improving the durability of the structure by suppressing the migration is also conceivable. However, this method is not preferable because it takes a long time to dry and harden the sealing material and deteriorates productivity.
As described above, the above-described conventional divided ceramic structure still has room for improvement in durability and the like as a ceramic structure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned various problems of the prior art, and a main object thereof is to improve the durability of a ceramic structure.

It is another object of the present invention to improve material properties such as adhesiveness of a sealing material at normal temperature and high temperature.

Still another object of the present invention is to improve the durability and durability of a divided ceramic structure by improving the adhesiveness and thermal conductivity of a sealing material at normal temperature and high temperature while maintaining elasticity and heat resistance. It is to improve both of the regeneration efficiency at the same time.

[0014]

In order to achieve the above object,
As a result of his intensive research, he found an invention having the following features. That is, the present invention has a plurality of through holes arranged in parallel along the longitudinal direction, and each end face of these through holes is plugged in a checkered pattern, and the gas enters and exits. The opening and closing are in the opposite relationship with the side, and the adjacent one of these through holes is a ceramic structure that is made by assembling a plurality of ceramic members that are mutually permeable through porous partition walls. In, between the ceramic members,
At least an inorganic fiber, an inorganic binder, filled with an organic binder and inorganic particles, dried and cured, the inorganic fibers, the inorganic particles, and ceramics generated by heating and firing the inorganic binder, three-dimensional An elastic sealing material having a structure that intersects with each other is formed, and the ceramic members are integrally bonded through the sealing material .
In particular, as the inorganic particles, silicon carbide, silicon nitride,
And at least one inorganic selected from boron nitride
A ceramic structure using a powder or a whisker .

[0015] Here, in the sealing material, the inorganic fibers, silica - using alumina, mullite, at least one or more ceramic fibers selected from alumina and silica, the inorganic binder, at least selected from silica sol and alumina sol using one or more colloidal sol, and as the organic binder, polyvinyl alcohol, methyl cellulose, that are use of at least one or more kinds of polysaccharides selected from cellulose and carbomethoxy cellulose desirable.

More specifically, it is more preferable that the sealing material has the following configuration. . Among the ceramic fibers, the content of the silica-alumina ceramic fibers is 10 to 70 wt.
%, Preferably 10-40 wt%, more preferably 20-30 wt%
It is desirable that The reason is that if the content is less than 10% by weight, the effect as an elastic body is reduced, while if it exceeds 70% by weight, the thermal conductivity is reduced and the effect as an elastic body is reduced.

[0017] In the colloidal sol, the content of the silica sol is 1 to 30% by weight, preferably 1 to 15% by weight in solid content.
%, More preferably 5 to 9% by weight.
The reason for this is that if the content is less than 1 wt%, the adhesive strength will decrease, while if it exceeds 30 wt%, the thermal conductivity will decrease.

[0018] Among the polysaccharides, the content of carboxymethylcellulose is 0.1 to 5.0 wt%, preferably 0.2 to 1.0 wt%, more preferably 0.4 to 0.6 wt% in solid content. The reason is that migration cannot be suppressed if the content is less than 0.1 wt%, while 5.0 wt%
This is because, when the temperature exceeds 300 ° C., the organic binder is burned off due to a high-temperature heat history, and the strength is reduced.

[0019] It is desirable that the content of the silicon carbide powder in the inorganic powder or the whisker is 3 to 80% by weight, preferably 10 to 60% by weight, more preferably 20 to 40% by weight in solid content. The reason for this is that if the content is less than 3 wt%, the thermal conductivity will decrease, while if it exceeds 80 wt%, the adhesive strength at high temperatures will decrease.

[0020] Among the ceramic fibers constituting the sealing material, the silica-alumina ceramic fiber has a shot content of 1 to 10% by weight, preferably 1 to 10% by weight.
~ 5wt%, more preferably 1-3wt%, fiber length is 1 ~
100 mm, preferably 1 to 50 mm, more preferably 1 to 20 mm
It is desirable that The reason for this is that it is difficult to reduce the shot content to less than 1 wt% in production, and if the shot content exceeds 50 wt%, the material to be sealed (ceramic member)
Because it will hurt the wall. On the other hand, if the fiber length is less than 1 mm, an elastic structure cannot be formed, and if it exceeds 100 mm, the dispersion of inorganic fine particles becomes poor as a pill and the thickness of the sealing material cannot be reduced. This is because the thermal conductivity between the materials to be sealed is reduced.

[0021] Among the inorganic powders or whiskers constituting the sealing material, silicon carbide powder has a particle diameter of 0.01.
100100 μm, preferably 0.1 1515 μm, more preferably
It is desirable that the thickness be 0.1 to 10 μm. The reason for this is that if the particle size exceeds 100 μm, the adhesive strength (strength) and thermal conductivity decrease, while if it is less than 0.01 μm, the cost increases.

[0022]

The features of the ceramic structure according to the present invention are as follows.
The present invention is directed to a structure of a sealing material which can integrally bind a plurality of ceramic members and bind them. Specifically, first, the inorganic fibers and the organic binder constituting the sealing material are entangled with each other, thereby improving the uniformity of the structure and the bonding property in a low-temperature region, and improving the durability of the ceramic structure. It is in the point which made it. In other words, by adopting an organic binder that dries and cures early, it suppresses the occurrence of migration as seen in conventional sealing materials, maintains three-dimensional bonding between inorganic fibers, and reduces inorganic particles to inorganic fibers. The feature is that it is possible to immobilize. As a result, the sealing material is
An elastic material that is systematically uniform and has excellent adhesiveness, elasticity and strength can be obtained. As a result, a ceramic structure in which a plurality of ceramic members are integrally bound by such a sealing material can be externally formed. Even if it does not give the restraining force, it has sufficient adhesive strength and can release thermal stress at the same time.

The second feature is that the adhesive strength in a high temperature region can be maintained by the effect of the entanglement between the inorganic fibers and the inorganic binder constituting the sealing material. The reason is that in the high temperature region, the organic binder is removed by firing, but the inorganic binder is ceramicized by heating, and this ceramic is present at the intersection of the inorganic fibers, and the inorganic fiber and the ceramic member are joined. It is thought to contribute to. On the other hand, this inorganic binder
By drying and heating, the adhesive strength can be maintained even in a low temperature region.

Accordingly, a ceramic structure having excellent adhesive strength in a low temperature range and a high temperature range due to a synergistic effect between the above-mentioned effect due to the entanglement of ceramic fibers such as silica-alumina and an inorganic binder such as silica sol and the organic binder. can do.

A third feature is that the inorganic particles are interposed on the surface of the inorganic fiber and the surface and inside of the inorganic binder to improve the thermal conductivity of the ceramic structure. In particular, the thermal conductivity of nitride or carbide inorganic particles can be significantly improved due to the high thermal conductivity of nitride or carbide.

Therefore, the sealing material containing the inorganic particles is
Excellent in thermal conductivity, for example, when used in a filter for an exhaust gas purifying device, fills a gap formed when a plurality of ceramic members are combined, and at the same time, does not cause a temperature peak phenomenon at the time of regeneration. It can be effectively prevented. Moreover, the occurrence of cracks due to the heat cycle is reduced, the edge of the outer periphery of the filter can be heated in a relatively short time, and the regeneration efficiency can be improved.

Hereinafter, the ceramic structure of the present invention will be described in detail. When a ceramic structure is used as a filter for an exhaust gas purifying device, it is necessary that a sealing material constituting the filter has elasticity, thermal conductivity, bonding property, strength, etc. in addition to heat resistance. is there. If the elasticity is excellent, even when thermal stress is applied to the filter by heating, the thermal stress can be reliably released. In addition, when the heat conductivity is excellent, the heat of the heating element is quickly and uniformly transmitted to the entire structure, and the temperature difference inside the exhaust gas purification device is reduced. Further, if the bonding property and the strength are excellent, the adhesiveness between adjacently tied ceramic members is excellent, and the durability of the ceramic structure itself is also excellent.

According to the present invention, as the structure of the sealing material having the above-mentioned physical properties, the inorganic fiber and the inorganic particles, which use inorganic fibers, an inorganic binder, an organic binder and inorganic particles, and which are three-dimensionally intersected with each other, are used. It is characterized in that it is bonded to each other via an inorganic binder and an organic binder to form an elastic structure.

Here, the inorganic fiber includes silica-alumina ceramic fiber, mullite fiber, alumina fiber and silica fiber. Particularly, silica-alumina ceramic fiber is desirable, which has excellent elasticity and has a function of absorbing thermal stress. .

The inorganic binder is preferably a colloidal sol, for example, an alumina sol or a silica sol, and particularly preferably a silica sol, which acts as an adhesive (inorganic binder). This silica sol is easily available and easily converted to SiO ₂ by firing, so that it is suitable as an adhesive in a high-temperature region and has excellent insulating properties.

As the organic binder, a hydrophilic organic polymer is desirable, and a polysaccharide is more preferred. Specific examples include polyvinyl alcohol, methylcellulose, ethylcellulose, carboxymethylcellulose, etc., but carboxymethylcellulose is particularly desirable, which secures fluidity during assembly (contributes to improved workability) and has excellent adhesiveness in a normal temperature region. Is shown.

As the inorganic particles, carbide and / or nitride inorganic particles are desirable, for example, silicon carbide, silicon nitride and boron nitride. These carbides and nitrides
It has a very high thermal conductivity and contributes to the improvement of thermal conductivity by interposing on the surface and inside of the ceramic fiber and the colloidal sol. For example, the thermal conductivity of silicon carbide is 0.19ca
l / cm · sec · ° C, thermal conductivity of boron nitride is 0.136 cal / c
m · sec · ° C, whereas the thermal conductivity of alumina is 0.08
It is about cal / cm · sec · ° C., and it is understood that carbides and nitrides are particularly effective in improving the thermal conductivity. Among these carbide and nitride inorganic particles, silicon carbide is particularly optimal in terms of heat conduction. This is because boron nitride is less compatible with ceramic fibers than silicon carbide. That is, the reason is that silicon carbide has all of adhesiveness, heat resistance, water resistance and thermal conductivity.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a ceramic structure of the present invention is embodied in a filter for an exhaust gas purifying apparatus mounted on a diesel engine will be described below in detail with reference to FIGS. FIG. 1 is a diagram showing a filter 1 for an exhaust gas purifying apparatus using a ceramic structure of the present invention.
FIG. 2 is an enlarged partial cross-sectional view of the filter. In these figures, an exhaust gas purifying filter 1 comprises eight prismatic ceramic members 2 and four isosceles triangular ceramic members 3 each having a right-angle cross section and a sealing material made of an elastic material between the members. (Thickness: 1.5 to 3.0 mm) It is integrally bonded with 4 interposed. 3 to 5 are views showing a ceramic member 2 constituting a part of the filter 1 for an exhaust gas purification device. In these figures, the prismatic shape (33
In the ceramic member 2 of mm × 33 mm × 150 mm), a through-hole 2 a having a substantially square cross section is formed regularly along the axial direction. These through holes 2a are separated from each other by a porous partition wall 2b having a thickness of 0.3 mm. One end of each of the through holes 2a on the exhaust gas inflow side or the outflow side is sealed in a checkered pattern by a sealing piece 2c made of a porous sintered body. As a result, cells C1 and C2 that are open only on one of the inflow side and the outflow side of the ceramic member 2 are formed. The partition walls 2b of the cells C1 and C2 include:
An oxidation catalyst comprising a platinum group element, another metal element, an oxide thereof, or the like may be supported. This is because the particulates lower the ignition temperature of the particulates. The ceramic member 3 has the same configuration as the ceramic member 2 except that the cross-sectional shape is a right-angled isosceles triangle. Then, the filter 1 for the exhaust gas purifying apparatus of the present embodiment
In the case of the ceramic members 2 and 3 constituting
The thickness is set to 10 μm, the porosity to 43%, the cell wall thickness to 0.3 mm, and the cell pitch to 1.8 mm. In this embodiment, a filter 1 for an exhaust gas purifying apparatus having the above-described configuration is manufactured, and the performance of the filter is evaluated.

Example 1 (1) 51.5% by weight of α-type silicon carbide powder and β-type silicon carbide powder 22
% By weight, and the resulting mixture was mixed with an organic binder (methyl cellulose) and water at 6.5% by weight and 2% by weight, respectively.
0% by weight was added and kneaded. Next, a small amount of a plasticizer and a lubricant were added, and the mixture was further kneaded, and the kneaded product was extruded to obtain a honeycomb-shaped formed body. (2) Next, this formed body is dried using a microwave drier, and then the through-hole 2a of the formed body is sealed with a paste for forming a sealing piece 2c made of a porous sintered body. Then, the paste for sealing piece 2c was dried again using a dryer. After the dried body was degreased at 400 ° C., it was further baked at 2200 ° C. in an argon atmosphere to obtain porous honeycomb-shaped ceramic members 2 and 3. (3) Ceramic fiber (alumina silicate ceramic fiber, shot content 3%, fiber length 0.1 ~
100 mm) 23.3% by weight, average particle size 0.3 μm silicon carbide powder
30.2% by weight, 7% by weight of silica sol as an inorganic binder (the converted amount of SiO _{2 in} the sol is 30%), 0.5% by weight of carboxymethyl cellulose as an organic binder and 39% of water
% By weight, and the mixture was kneaded to form a paste to form a sealing material. (4) The sealing material is filled between the ceramic members 2 and 3 and dried and hardened at 50-100 ° C. × 1 hour, and the ceramic members 2 and 3 and the sealing material 4 are joined and integrated. A filter 1 as shown in FIG. The sealing material could be dried and cured without causing migration.

(Embodiment 2) This embodiment is basically the same as Embodiment 1, except that the sealing material is replaced with the one in Embodiment 1. Ceramic fiber (mullite fiber, shot content 5%, fiber length 0.1 to 100
mm) 25% by weight, 30% by weight of silicon nitride powder having an average particle size of 1.0 μm, 7% by weight of alumina sol as an inorganic binder (converted amount of alumina sol is 20%), 0.5% by weight of polyvinyl alcohol as an organic binder and 37.5% by weight of alcohol % And kneaded. The sealing material could be dried and cured without causing migration.

(Embodiment 3) This embodiment is basically the same as Embodiment 1, except that the sealing material is replaced with that of Embodiment 1 and is as follows. Ceramic fiber (alumina fiber, shot content 4%, fiber length 0.1-100
mm) 23% by weight, 35% by weight of boron nitride powder having an average particle diameter of 1 μm, 8% by weight of alumina sol as an inorganic binder (converted amount of alumina sol is 20%), 0.5% by weight of ethyl cellulose as an organic binder and 35.5% by weight of acetone. What was mixed and kneaded was used. The sealing material could be dried and cured without causing migration.

(Comparative Example 1) This example is basically the same as Example 1, except that the sealing material in Example 1 is replaced with the following sealing material, which is a conventional sealing material. Finally, the outermost peripheral portion of the filter 1 was coated with a ceramic fiber heat insulating material (ceramic fiber 63% by weight, α-sepiolite 7% by weight, unexpanded vermiculite 20% by weight, and organic binder 10% by weight). Ceramic fiber (alumina-silica fiber, shot content 2.7
%, A fiber length of 30 to 100 mm), 44.2% by weight, 13.3% by weight of a silica sol as an inorganic binder and 42.5% by weight of water, and the mixture was kneaded and used in the form of a paste or a sheet. In addition, the said sealing material caused migration when drying and hardening.

The performance of the filters 1 produced in Examples 1 to 3 and Comparative Example 1 was evaluated by the following method. (Measurement of adhesive strength at initial stage and after heat cycle) FIG.
As shown in (1), three ceramic members were cut out from the filter 1 as test pieces, a load was applied to the center ceramic member, and the load when peeling occurred was measured. Further, in actual use, rapid heating and cooling from room temperature to 900 ° C. are expected. Therefore, those subjected to a heat cycle test from room temperature to 900 ° C. were also evaluated. Table 1 shows the measurement results of the adhesive strength between the ceramic members 2 and 3 constituting the filter 1 at the initial stage and after the heat cycle (after 100 times).

[0039]

[Table 1] The reason why the strength is improved after the heat cycle is that
It is presumed to be due to the sintering action of silica by heating at 900 ° C.

(Measurement of Thermal Conductivity) As shown in FIG. 7, four ceramic members are cut out as test pieces, the outer periphery is surrounded by a heat insulating material, and placed on a heater 6 for heating for 20 minutes. At this time, the temperature difference between T1 and T2 was measured. In Table 2,
The result of having measured the temperature difference of T1 and T2 shown in FIG. 7 about each of Examples 1-3 and the comparative example was shown.

[0041]

[Table 2]

As is evident from the above results, the filter using the ceramic structure of the present invention has extremely high adhesive strength even at a high temperature and a normal temperature, and has excellent heat cycle characteristics. It was confirmed that it had excellent properties. Moreover, since the ceramic structure also has excellent thermal conductivity, it is possible to reduce the occurrence of peak temperature in the ceramic member located inside the filter, and to shorten the time required for the ceramic structure located at the edge portion to rise. As a result, it is possible to simultaneously improve the reproduction efficiency.

The structure of the filter 1 to which the ceramic structure of the present invention is applied is not limited to the structure described in the above embodiment, but can be changed to the following structure. For example, (a) The number of combinations of ceramic members need not be twelve as in the above embodiment, but can be any number. In this case, it is of course possible to appropriately combine and use ceramic members having different sizes and shapes.
It should be noted that adopting a configuration in which a plurality of ceramic members are combined is particularly advantageous when manufacturing a large-sized filter for an exhaust gas purification device. (B) The filter 1 of the embodiment can be regarded as a state in which one large filter is divided into a plurality of pieces along the axial direction. Thus, for example, a modified example in which the filter is divided into a donut shape, a state in which the filter is divided perpendicularly to the axial direction, and the like can be considered. (C) The present invention is not limited to only the honeycomb-shaped ceramic members 2 and 3 as shown in the above-described embodiment, and it is of course possible to adopt a three-dimensional network structure, a foam shape, a noodle shape, a fiber shape, or the like. In addition, ceramic members 2 and 3
Of course, a material other than silicon carbide may be selected. (D) When constituting the filter 1, the ceramic member 2,
A configuration may be adopted in which a heater is provided between the three. In this case, the heater is not limited only to a metal wire.
That is, the heater may be manufactured by a method such as metal metallization, printing of a conductive paste, or sputtering.

In this embodiment, an example has been described in which the ceramic structure of the present invention is embodied as a filter for an exhaust gas purifying apparatus attached to a diesel engine. Besides, for example, it can be used as a member for a heat exchanger or a filter for filtering high-temperature fluid or high-temperature steam.

[0045]

As described above, the ceramic structure of the present invention has excellent adhesive strength and excellent thermal conductivity regardless of the temperature. , And improvement in reproduction efficiency and durability can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a filter for an exhaust gas purification device using a ceramic structure of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a filter for an exhaust gas purification device using the ceramic structure of the present invention.

FIG. 3 is a perspective view showing a ceramic member of the filter for an exhaust gas purifying apparatus according to the present invention.

FIG. 4 is a partially broken enlarged sectional view taken along line AA of FIG. 3;

FIG. 5 is an enlarged sectional view taken along line BB of FIG. 4;

FIG. 6 is an explanatory diagram of a measurement test of an adhesive strength.

FIG. 7 is an explanatory diagram of a measurement test of thermal conductivity.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter for exhaust gas purification apparatus 2, 3 Ceramic member 4 Sealing material 5 Heat insulating material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Shimato, 1-1 Ibigawa-cho, Ibi-gun, Ibi-gun, Gifu Prefecture Inside (ibid) Co., Ltd. (72) Hiroshi Okazoe 1-1-1, Oaza, Ageo, Saitama Prefecture In-company (72) Inventor Masaki Iwahiro 1-chome, 1-chome, Ageo-shi, Saitama Nissan Diesel Industry Co., Ltd. (56) References JP-A-3-121213 (JP, A) JP-A-6-9253 ( JP, A) JP-A-2-259190 (JP, A) JP-A-6-47620 (JP, U) JP-A-1-63715 (JP, U) JP-B-57-5429 (JP, B2) JP-B 51-43485 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01N 3/02 301 B01D 39/20 C04B 37/00

Claims (3)

(57) [Claims] 1. A plurality of through holes arranged in parallel along the longitudinal direction, and each end face of each of these through holes is plugged in a checkered pattern, and the gas inlet and outlet sides. The opening and closing are in the opposite relationship, and the adjacent ones of these through-holes are connected to each other through a porous partition in a ceramic structure formed by binding a plurality of ceramic members that can be permeable to each other. A space between at least each of the ceramic members is filled with at least an inorganic fiber, an inorganic binder, an organic binder and inorganic particles, dried and cured, and the inorganic fiber, the inorganic particles, and the inorganic binder are heated and fired. and the ceramics produced by us form building the elastic membrane sealing material three-dimensionally interlaced structures, said each ceramic member through the sealing member is bonded together , In particular the inorganic
Particles from silicon carbide, silicon nitride, and boron nitride
At least one or more inorganic powders or whiskers selected
A ceramic structure characterized by using a ceramic material. 2. In the sealing material , as an inorganic fiber,
The silica - alumina, mullite, using at least one or more ceramic fibers selected from alumina and silica, the inorganic binder, using at least one or more kinds of colloidal sol selected from silica sol and alumina sol, and the organic binder , polyvinyl alcohol, methyl cellulose, ceramic structure according to claim 1, characterized in that there use at least one kind of polysaccharide selected from ethyl cellulose and carbomethoxy cellulose. 3. The sealing material has a solid content of 10 to 70 wt%.
Silica-alumina ceramic fiber, 1-30wt%
The ceramic structure according to claim 2, comprising: silica sol of 0.1 to 5.0 wt% carbomethoxycellulose and 3 to 80 wt% silicon carbide powder.