JP2012045523A - Honeycomb structure and method for producing the same - Google Patents
Honeycomb structure and method for producing the same Download PDFInfo
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- 238000005192 partition Methods 0.000 claims abstract description 160
- 239000002245 particle Substances 0.000 claims abstract description 85
- 239000000454 talc Substances 0.000 claims abstract description 61
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- 239000002002 slurry Substances 0.000 claims abstract description 50
- 229910052878 cordierite Inorganic materials 0.000 claims abstract description 22
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000000034 method Methods 0.000 claims abstract description 14
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- 238000002844 melting Methods 0.000 claims description 19
- 230000008018 melting Effects 0.000 claims description 19
- FPAFDBFIGPHWGO-UHFFFAOYSA-N dioxosilane;oxomagnesium;hydrate Chemical compound O.[Mg]=O.[Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FPAFDBFIGPHWGO-UHFFFAOYSA-N 0.000 claims description 15
- 239000012779 reinforcing material Substances 0.000 claims description 14
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- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
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- 238000006243 chemical reaction Methods 0.000 description 2
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- 150000003624 transition metals Chemical class 0.000 description 2
- 241001343369 Aegle <moth> Species 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 1
- WYTGDNHDOZPMIW-RCBQFDQVSA-N alstonine Natural products C1=CC2=C3C=CC=CC3=NC2=C2N1C[C@H]1[C@H](C)OC=C(C(=O)OC)[C@H]1C2 WYTGDNHDOZPMIW-RCBQFDQVSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
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- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
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- 239000004014 plasticizer Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
- Catalysts (AREA)
Abstract
Description
本発明は、少なくとも隔壁の一部に隔壁強化剤を付着することで、隔壁の一部を強化して、耐エロージョン性を向上させたコーディエライトハニカム構造体とその製造方法に関する。 The present invention relates to a cordierite honeycomb structure in which a partition wall reinforcing agent is attached to at least a part of partition walls to enhance part of the partition walls to improve erosion resistance, and a method for manufacturing the cordierite honeycomb structure.
排ガス浄化用の触媒担体等に広く用いられているハニカム構造体にあっては、年々強化される排ガス規制に対応すべく、より高い浄化性能が求められており、その一方で、低燃費化、高出力化等の要請から、圧力損失の低減も求められている。
かかる状況下、ハニカム構造体の隔壁の厚さをいっそう薄くすることで、ハニカム構造体のセル開口端面における開口率を高めて圧力損失を低減し、かつ隔壁の熱容量を低減してエンジン始動後に早期に触媒を活性化させ、浄化性能を向上させる動きが強まっている。
In honeycomb structures widely used for exhaust gas purification catalyst carriers, etc., higher purification performance is required to meet exhaust gas regulations that are strengthened year by year. Due to the demand for higher output, reduction of pressure loss is also required.
Under such circumstances, by further reducing the thickness of the partition walls of the honeycomb structure, the aperture ratio at the cell opening end face of the honeycomb structure is increased to reduce the pressure loss, and the heat capacity of the partition walls is reduced, so that the early stage after engine start-up There is an increasing trend to activate the catalyst and improve the purification performance.
他方、ハニカム構造体の薄壁化の進展に伴い、排ガスがハニカム構造体のセル開口から進入するときに排ガス中に含まれる固体粒子の衝突、転がりや渦流の発生等によってセル開口端部におけるセル隔壁の摩耗を引き起こすエロージョン現象が、新たな問題となっている。
かかる問題に対しセル開口端部に存在するセル隔壁に、他のセル隔壁よりも強度を向上させたセル開口端隔壁セル隔壁強化部を設けたハニカム構造体について種々提案されている。
On the other hand, with the progress of thinning of the honeycomb structure, the cells at the cell opening end are caused by collision of solid particles contained in the exhaust gas, generation of rolling or vortex when the exhaust gas enters from the cell opening of the honeycomb structure. The erosion phenomenon that causes the partition wall to wear becomes a new problem.
In order to solve this problem, various honeycomb structures have been proposed in which cell partition walls present at the cell opening end portions are provided with cell opening end partition wall cell partition reinforcing portions that have higher strength than other cell partition walls.
例えば、特許文献１では、コーディエライト化原料を主成分とするハニカム状の成形体を作製した後、この成形体のセル開口端部を、コーディエライトの融点低下成分であるタルクを溶媒に分散・混合させたセル開口端壁強化用スラリーに浸漬し、その後、乾燥、焼成してセル開口端部壁を強化する方法が提案されている。
この方法は、コーディエライトの融点低下による局所的な溶融を利用して、セル開口端部に存在するセル隔壁の気孔を減少させることにより、セル隔壁セル隔壁強化部を形成するものであり、セル隔壁の厚肉化を伴わないため、ハニカム構造体の圧力損失を増大させることなく、耐エロージョン性を向上させることができる。
For example, in Patent Document 1, after forming a honeycomb-shaped formed body mainly composed of a cordierite-forming raw material, a cell opening end portion of the formed body is used as a solvent with talc, which is a component for decreasing the melting point of cordierite. There has been proposed a method in which the cell opening end wall is reinforced by dipping in a dispersed / mixed slurry for reinforcing the cell opening end wall, and then drying and firing.
This method uses the local melting due to the lowering of the melting point of cordierite, and reduces the pores of the cell partition wall present at the cell opening end, thereby forming the cell partition cell partition reinforced portion, Since the cell partition wall is not thickened, the erosion resistance can be improved without increasing the pressure loss of the honeycomb structure.
ところが、本発明者らの鋭意試験により、セル開口端部に含浸させるセル開口端壁強化用スラリー中に含まれるタルク粒子の内、特定の粒径以上の大きな粒子が存在すると、その周囲に過剰なコーディエライトの融点降下を招き、局所的な溶損が発生し、セル開口壁セル隔壁強化部にφ１００μｍ以上の大きな粗大空孔が発生する虞があることが判明した。
このような粗大空孔は、セル開口壁セル隔壁強化部の局所的な耐エロージョン性の低下を招いたり、触媒を担持する際に触媒の偏在による過剰昇温等を招いたり、薄肉のセル隔壁を貫通する欠陥となる虞がある。
However, when talc particles contained in the slurry for reinforcing the cell opening end wall impregnated in the cell opening end are present in a large particle having a specific particle size or more by an intensive study by the present inventors, an excessive amount is present around the talc particle. As a result, the melting point of cordierite was lowered, local melting loss was generated, and large coarse pores of φ100 μm or more might be generated in the cell opening wall cell partition wall reinforced portion.
Such coarse pores may cause local erosion resistance deterioration of the cell opening wall cell partition reinforcement part, excessive temperature rise due to uneven distribution of the catalyst when the catalyst is supported, etc. There is a risk of a defect penetrating through.
また、セル隔壁強化用スラリーを作製するに当たり、セル隔壁強化用スラリーの主原料となるタルクは、嵩密度が低く、分散媒に浮き易いので、完全な分散状態とするのに時間が掛かる。 Further, in producing the slurry for reinforcing the cell partition walls, talc, which is the main raw material of the slurry for cell partition reinforcements, has a low bulk density and tends to float on the dispersion medium, so it takes time to achieve a completely dispersed state.
そこで、本発明は、かかる実情に鑑み、セル開口端壁強化用スラリー中に含まれるタルクの粒径を特定することにより、欠陥の少ないセル開口端壁セル隔壁強化部を設けたハニカム構造体を提供すると共に、作業効率の良いハニカム構造体の製造方法を提供すること目的とするものである。 Therefore, in view of such circumstances, the present invention specifies a honeycomb structure provided with a cell opening end wall cell partition wall reinforcing portion with few defects by specifying the particle size of talc contained in the cell opening end wall reinforcing slurry. An object of the present invention is to provide a method for manufacturing a honeycomb structure with good working efficiency.
第１の発明では、多孔質セラミック材料からなるセル隔壁に区画されたセルを複数配設してハニカム状としたハニカム構造体の一方、又は、両方の開口端面から所定の範囲にセル隔壁一般部よりも気孔率の低いセル隔壁強化部を設けたハニカム構造体において、上記セル隔壁強化部にガス流れに垂直な方向から観察したとき１００μｍ以上の粗大空孔が実質存在しないことを特徴とする（請求項１）。 In the first aspect of the invention, the cell partition general portion is disposed within a predetermined range from one or both of the opening end faces of the honeycomb structure in which a plurality of cells partitioned into the cell partition made of a porous ceramic material are arranged in a honeycomb shape. In the honeycomb structure provided with the cell partition wall reinforced portion having a lower porosity, the cell partition wall reinforced portion is substantially free of coarse pores of 100 μm or more when observed from a direction perpendicular to the gas flow ( Claim 1).
本発明者等の鋭意試験により、第１の発明のように、上記セル隔壁強化部に１００μｍ以上の粗大空孔が実質存在しなければ、上記セル隔壁強化部の耐エロージョン性が高くなることが判明した。 As a result of the diligent tests of the present inventors, the erosion resistance of the cell partition wall reinforced portion may be enhanced if there is substantially no coarse pore of 100 μm or more in the cell partition wall reinforced portion as in the first invention. found.
第２の発明では、上記セル隔壁強化部の表面粗さが上記セル隔壁一般部の表面粗さより粗いことを特徴とする（請求項２）。 According to a second aspect of the present invention, the surface roughness of the cell partition wall reinforcing portion is rougher than the surface roughness of the cell partition wall general portion (claim 2).
第２の発明によれば、上記ハニカム構造体を、触媒担体として用いた場合に、上記セル隔壁一般部に比べ気孔率の低い上記セル隔壁強化部に担持できる触媒量を表面積が大きくなることによって補うことができ、上記セル隔壁一般部と上記セル隔壁強化部とで触媒担持量の均一化が図られる。
このため、触媒担持量の不均一さに伴うハニカム構造体の局所的な破壊を招く虞がない。
According to the second invention, when the honeycomb structure is used as a catalyst carrier, the amount of catalyst that can be supported on the cell partition reinforced portion having a porosity lower than that of the general portion of the cell partition is increased. The amount of catalyst supported can be made uniform between the cell partition wall general part and the cell partition wall reinforcing part.
For this reason, there is no possibility of causing local destruction of the honeycomb structure due to non-uniform catalyst loading.
具体的には、第３の発明のように、上記セル隔壁強化部の表面粗さが１２〜２１μｍＲｚｊｉｓであり、上記セル隔壁一般部の表面粗さが１０〜１５μｍＲｚｊｉｓある（請求項３）。 Specifically, as in the third invention, the cell barrier reinforced portion has a surface roughness of 12 to 21 μm Rz cis , and the cell barrier general portion has a surface roughness of 10 to 15 μm Rz jis (Claim 3). .
第３の発明によれば、上記セル隔壁一般部と上記セル隔壁強化部とに担持できる触媒量を均一化し、ハニカム構造体を信頼性の高い排ガス浄化触媒として用いることができる。 According to the third aspect of the present invention, the amount of catalyst that can be supported on the cell partition wall general part and the cell partition wall reinforcing part is made uniform, and the honeycomb structure can be used as a highly reliable exhaust gas purification catalyst.
第４の発明では、コーディライト材料からなるセル隔壁に区画されたセルを複数配設してハニカム状としたハニカム構造体の一方又は両方の開口端部にセル隔壁強化材料を含むセル隔壁強化用スラリーを含浸せしめて、乾燥し、焼成して、セル隔壁一般部よりも気孔率の低いセル隔壁強化部を形成するハニカム構造体の製造方法において、上記セル隔壁強化材料の主原料粒子から、所定の粒径以上の粗大粒子を除去して上記セル隔壁強化用スラリーを作製することを特徴とする（請求項４）。 In the fourth invention, a cell partition reinforcing material including a cell partition reinforcing material at one or both opening end portions of a honeycomb structure in which a plurality of cells partitioned into a cell partition made of cordierite material are disposed to form a honeycomb shape. In a method for manufacturing a honeycomb structure in which slurry is impregnated, dried and fired to form a cell partition wall reinforcing portion having a lower porosity than the cell partition wall general portion, the main raw material particles of the cell partition wall reinforcing material are Coarse particles having a particle size equal to or larger than the above are removed to prepare the cell partition wall reinforcing slurry (claim 4).
第４の発明によれば、上記セル隔壁の局所的な溶損が起こり難くなり、セル隔壁強化部にガス流れに垂直な方向から観察したとき１００μｍ以上の粗大空孔が実質存在しないハニカム構造体を製造することができる。 According to the fourth invention, a honeycomb structure in which local melting damage of the cell partition wall hardly occurs and a coarse pore of 100 μm or more does not substantially exist in the cell partition wall reinforced portion when observed from a direction perpendicular to the gas flow. Can be manufactured.
第５の発明では、上記セル隔壁強化材料の主原料粒子から、所定の粒径以下の微細粒子を除去して上記セル隔壁強化用スラリーを作製する（請求項５）。 In the fifth aspect of the invention, the cell partition wall reinforcing slurry is prepared by removing fine particles having a predetermined particle diameter or less from the main raw material particles of the cell partition wall reinforcing material.
第５の発明によれば、上記セル隔壁強化材料を速やかに分散させることができ上記セル隔壁強化用スラリーを作製する際の作業性が向上すると共に、上記微細粒子が凝集した状態で上記セル隔壁強化部表面に付着し難くなるので、上記セル隔壁強化材料の過剰な反応を抑制し、耐エロージョン性に優れたハニカム構造体に局所的な溶損を発生させることなく製造することができる。 According to the fifth aspect of the present invention, the cell partition wall reinforcing material can be quickly dispersed to improve the workability when producing the cell partition wall reinforcing slurry, and the cell partition wall is in a state where the fine particles are aggregated. Since it becomes difficult to adhere to the surface of the reinforced portion, an excessive reaction of the cell partition wall reinforcing material can be suppressed, and the honeycomb structure having excellent erosion resistance can be manufactured without causing local erosion.
具体的には、第６の発明では、上記セル隔壁強化材料がコーディエライトの融点を低下させるタルク粉末であり、上記粗大粒子として５０μｍ以上の粗大タルク粒子を除去する。 Specifically, in the sixth invention, the cell partition wall reinforcing material is talc powder that lowers the melting point of cordierite, and coarse talc particles of 50 μm or more are removed as the coarse particles.
本発明者等の鋭意試験により、第６の発明によれば、コーディエライトの過剰な融点降下を招く虞がなく、セル隔壁強化部に１００μｍ以上の粗大空孔が実質存在せず、耐エロージョン性に優れたコーディエライトハニカム構造体を製造することができることが判明した。 According to the sixth aspect of the present invention, the inventors have conducted an intensive test, and there is no fear of causing an excessive melting point of cordierite, and there is substantially no coarse pore of 100 μm or more in the cell partition wall reinforced portion, and erosion resistance It has been found that a cordierite honeycomb structure having excellent properties can be produced.
第７の発明では、上記微細粒子として５μｍ以下の微細タルク粒子を除去する。 In the seventh invention, fine talc particles of 5 μm or less are removed as the fine particles.
第７の発明によれば、上記セル隔壁強化材料として用いられたタルク粉末を速やかに分散させることができ上記セル隔壁強化用スラリーを作製する際の作業性が向上すると共に、上記微細粒子が凝集した状態で上記セル隔壁強化部表面に付着し難くなるので、上記セル隔壁強化材料の過剰な反応を抑制し、耐エロージョン性に優れたコーディエライトハニカム構造体に局所的な溶損を発生させることなく製造することができる。 According to the seventh invention, the talc powder used as the cell partition wall reinforcing material can be quickly dispersed, and the workability in producing the cell partition wall reinforcing slurry is improved, and the fine particles are aggregated. In such a state, it becomes difficult to adhere to the surface of the cell partition reinforced portion, so that excessive reaction of the cell partition reinforced material is suppressed, and local erosion is generated in the cordierite honeycomb structure having excellent erosion resistance. It can be manufactured without.
本発明の第１の実施形態におけるハニカム構造体１０は、エンジン等の燃焼機関から排出される排ガスを被処理ガスとして、被処理ガス中に含まれる、ＨＣ、ＣＯ、ＮＯｘ等の有害物質の浄化装置に排ガス浄化用触媒１の触媒担体として好適なものである。
図１を参照して、本発明の第１の実施形態におけるハニカム構造体１０について説明する。
ハニカム構造体１０は、コーディエライト材料を主成分とする多孔質セラミック材料からなり、略筒状に形成された基体外皮部１２０の内側に、セル隔壁１００によって区画され、長手方向に伸びるセル１０１が複数配設されたハニカム構造となっている。
さらに、本発明のハニカム構造体１０は、少なくとも、被処理ガスが流入する入口側となる一方のセル開口端面１１におけるセル隔壁１００に、セル隔壁強化部１１０を設けて、耐エロージョン性を向上させてある。
また、セル隔壁一般部１００、及び、セル隔壁強化部１１０の表面には、Ｐｔ等の遷移金属からなる触媒３０が担持され、排ガス浄化用触媒１を構成している。
セル隔壁一般部１００の表面粗さ（１０点平均（ＪＩＳ−Ｂ０６０１（２００１）））は、隔壁の角部を除く直線部において、１０〜１５μｍＲｚｊｉｓであるのに対し、セル隔壁強化部１１０の表面粗さは、１２〜２１μｍＲｚｊｉｓとなっている。
セル隔壁強化部１１０は、セル隔壁一般部１００に比べ、緻密化され、気孔率が低くなっているため、表面粗さをセル隔壁一般部１００よりも粗くすることにより、セル隔壁一般部１００とセル隔壁強化部１１０とで触媒３０の担持量に差が生じ難くなっている。
また、本発明のハニカム構造体１０では、セル隔壁強化材料として、コーディエライトの融点を降下させるタルク粉末を分散させたセル隔壁強化用スラリー２０をセル開口端面１１から所定の範囲Ｌだけ含浸させ、セル隔壁強化部１１０を形成している。
このとき、セル隔壁強化用スラリー２０の主原料粒子であるタルク粉末から５０μｍ以上の粗大タルク粒子を取り除くことにより、過剰な融点降下が抑制されているのでセル隔壁強化部１１０の表面に、φ１００μｍ以上の粗大空孔の発生を回避することができることが判明した。
本実施形態におけるハニカム構造体１０の開口端面より３ｍｍ以内にて、ガス流れに垂直な方向から３０セルについてセル隔壁強化部１１０の観察を行ったが、粗大空孔が実質存在しないことが確認された。
なお、本実施形態においては、ハニカム構造体１０は、セル隔壁１００の板厚が６５μｍ、セル密度が９００ｃｐｓｉ、気孔率が３５％に形成されている。
ハニカム構造体１０の一方のセル開口端面１１からセル１０１内に流入した被処理ガスは、セル１０１を通過する間に、セル隔壁１００の表面に担持された触媒３０によって浄化され、他方のセル開口端部１２から排出される。
また、本実施形態では、セル隔壁強化部１１０を被処理ガスの入口となる一方のセル開口端面１１に設けた場合を示したが、処理済みガスの出口となる他方のセル開口端面１２との両方にセル壁強化部を設けても良い。
The honeycomb structure 10 according to the first embodiment of the present invention is a purification of harmful substances such as HC, CO, NOx, etc. contained in the gas to be treated, using the exhaust gas discharged from a combustion engine such as an engine as the gas to be treated. The apparatus is suitable as a catalyst carrier for the exhaust gas-purifying catalyst 1.
A honeycomb structure 10 according to a first embodiment of the present invention will be described with reference to FIG.
The honeycomb structure 10 is made of a porous ceramic material mainly composed of cordierite material. The honeycomb structure 10 is partitioned by a cell partition wall 100 inside a substrate skin portion 120 formed in a substantially cylindrical shape, and extends in a longitudinal direction. Has a honeycomb structure.
Furthermore, the honeycomb structure 10 of the present invention is provided with a cell partition wall reinforcing portion 110 at least on the cell partition wall 100 on one cell opening end surface 11 on the inlet side into which the gas to be processed flows, thereby improving the erosion resistance. It is.
Further, a catalyst 30 made of a transition metal such as Pt is supported on the surfaces of the cell partition wall general part 100 and the cell partition wall reinforcing part 110, thereby constituting the exhaust gas purification catalyst 1.
The surface roughness (10-point average (JIS-B0601 (2001))) of the cell partition wall general portion 100 is 10 to 15 μm Rz jis in the straight line portion excluding the corners of the partition wall, whereas The surface roughness is 12 to 21 μm Rz cis .
The cell partition wall reinforced portion 110 is densified and has a lower porosity than the cell partition wall general portion 100. Therefore, by making the surface roughness rougher than the cell partition wall general portion 100, It is difficult for a difference in the amount of the catalyst 30 supported between the cell partition wall reinforcing portion 110 and the cell partition reinforcing portion 110.
Further, in the honeycomb structure 10 of the present invention, a cell partition reinforcing slurry 20 in which talc powder for lowering the melting point of cordierite is dispersed is impregnated as a cell partition reinforcing material from the cell opening end face 11 by a predetermined range L. The cell partition reinforcing part 110 is formed.
At this time, by removing coarse talc particles of 50 μm or more from the talc powder that is the main raw material particles of the cell partition wall reinforcing slurry 20, an excessive melting point drop is suppressed, so that the surface of the cell partition wall reinforcing portion 110 has a diameter of 100 μm or more. It has been found that the generation of coarse pores can be avoided.
The cell partition wall reinforced portion 110 was observed for 30 cells from the direction perpendicular to the gas flow within 3 mm from the opening end face of the honeycomb structure 10 in the present embodiment, and it was confirmed that coarse pores were not substantially present. It was.
In the present embodiment, the honeycomb structure 10 is formed such that the cell partition wall 100 has a thickness of 65 μm, a cell density of 900 cpsi, and a porosity of 35%.
The gas to be treated that flows into the cell 101 from one cell opening end face 11 of the honeycomb structure 10 is purified by the catalyst 30 supported on the surface of the cell partition wall 100 while passing through the cell 101, and the other cell opening. It is discharged from the end 12.
Further, in the present embodiment, the case where the cell partition wall reinforcing portion 110 is provided on one cell opening end surface 11 serving as an inlet of the gas to be processed has been described. You may provide a cell wall reinforcement | strengthening part in both.
図２を参照して、本発明のハニカム構造体１０の製造方法について説明する。
ハニカム構造体１０を製造するに当たっては、まず、コーディエライトを生成し得るコーディエライト化原料を主成分とし、これに、分散材、結合材、可塑剤、水等を適宜添加し、分散、混合、混練等の公知の方法により、坏土を形成し、坏土を金型から押し出して複数のセルが区画されたハニカム状の押出成形体を形成し、乾燥して乾燥体１０Ａを形成する。
次いで、乾燥体１０Ａの少なくとも一方のセル開口端面１１のセル隔壁１００にセル隔壁強化部１１０を形成すべく、以下のようにディップ処理を行う。
まず、本発明の要部であるセル隔壁強化用スラリー２０を以下の手順によって作製する。
隔壁強化用スラリー２０は、主原料として、平均粒径１５μｍの粒径を有するタルク粉末が用いられるが、本発明においては、原料となるタルク粉末から所定の粒径以上の粗大粒子として粒径５０μｍ以上の粗大タルク粒子と所定の粒径以下の微細粒子として粒径５μｍ以下の微細タルク粒子とが、分級等により除去されていることを特徴としている。
このように、特定の範囲の粒径のタルク粒子が取り除かれたタルク粉末を、例えば、ＡＦソルベント（日本石油（株）製）等の非芳香族石油系溶剤からなる分散媒に加え、所定の濃度（例えば、３０ｗｔ％）に調整し、撹拌、超音波照射、又は、ミリング等の公知の方法により分散させ、セル隔壁強化用スラリー２０を得る。このとき、必要に応じて、分散剤、結合材等を加えても良い。
With reference to FIG. 2, the manufacturing method of the honeycomb structure 10 of this invention is demonstrated.
In manufacturing the honeycomb structure 10, first, a cordierite-forming raw material capable of generating cordierite is a main component, and a dispersion material, a binder, a plasticizer, water and the like are appropriately added thereto, and dispersed. A kneaded material is formed by a known method such as mixing and kneading, and the kneaded material is extruded from a mold to form a honeycomb-shaped extruded body in which a plurality of cells are partitioned, and dried to form a dried body 10A. .
Next, in order to form the cell partition wall reinforcing portion 110 on the cell partition wall 100 on at least one cell opening end surface 11 of the dry body 10A, the dipping process is performed as follows.
First, the cell partition wall reinforcing slurry 20 which is the main part of the present invention is prepared by the following procedure.
In the partition wall reinforcing slurry 20, a talc powder having an average particle size of 15 μm is used as a main raw material. In the present invention, a coarse particle having a particle size of 50 μm or more as a coarse particle having a predetermined particle size or more is used as a raw material. The above-mentioned coarse talc particles and fine talc particles having a particle size of 5 μm or less as fine particles having a predetermined particle size or less are removed by classification or the like.
In this way, the talc powder from which talc particles having a specific range of particle sizes have been removed is added to a dispersion medium composed of a non-aromatic petroleum solvent such as AF solvent (manufactured by Nippon Oil Co., Ltd.) The slurry is adjusted to a concentration (for example, 30 wt%) and dispersed by a known method such as stirring, ultrasonic irradiation, or milling to obtain a cell partition wall reinforcing slurry 20. At this time, a dispersant, a binder, or the like may be added as necessary.
一般に、タルク粉末は、板状粒子であり、嵩密度も低いため、分散媒表面に浮遊し易く、分散媒に濡れ難い。
特に、微細タルク粒子は表面積が大きく、表面に気体が多く吸着しており、分散媒表面に浮遊し易く、従来にセル隔壁強化用スラリーでは、浮遊した微細タルク粒子が凝集状態でハニカム構造体に付着し、局所的な溶損を起こしたり、微細タルク粒子を分散媒に完全に分散させるための作業に時間を要したりしていた。
しかし、本発明では、５μｍ以下の微細タルク粒子が除去されているので、タルク粉末を比較的短時間に分散させることができ、タルク粉末の凝集状態での付着を防止して、局所的な溶損を防止できると共に、セル隔壁強化用スラリーの作製が容易で、作業効率が向上している。
In general, talc powder is a plate-like particle and has a low bulk density, so that it easily floats on the surface of the dispersion medium and is difficult to get wet with the dispersion medium.
In particular, the fine talc particles have a large surface area and a large amount of gas is adsorbed on the surface, and are easy to float on the surface of the dispersion medium. Conventionally, in the slurry for reinforcing the cell partition walls, the suspended fine talc particles are aggregated in the honeycomb structure. It adheres and causes local melting damage, and it takes time to completely disperse fine talc particles in a dispersion medium.
However, in the present invention, since fine talc particles of 5 μm or less are removed, the talc powder can be dispersed in a relatively short time, and adhesion of the talc powder in an agglomerated state can be prevented to prevent local dissolution. In addition to preventing damage, it is easy to produce a slurry for reinforcing the cell partition walls, and the working efficiency is improved.
さらに、図２（ａ）に示すように、セル隔壁強化用スラリー２０を、所定の深さ（例えば、２ｍｍ）まで容器に入れ、エアブロー等で表面に付着した粉体を除去した乾燥体１０Ａの端面を浸漬させ、乾燥体１０Ａの端面から所定の範囲Ｌ（例えば、３ｍｍ）だけセル隔壁強化用スラリー２０を含浸させる。 Further, as shown in FIG. 2A, the cell partition wall reinforcing slurry 20 is put in a container to a predetermined depth (for example, 2 mm), and the dry body 10A from which the powder adhered to the surface is removed by air blow or the like is removed. The end face is immersed, and the cell partition wall reinforcing slurry 20 is impregnated from the end face of the dry body 10A by a predetermined range L (for example, 3 mm).
次いで、セル隔壁強化用スラリー２０を含浸させた図２（ｂ）に示すように、セル隔壁強化用スラリー２０を含浸したセル開口端面１１に対向するセル開口端部１２から、所定の圧力の圧縮空気（例えば、０．２ｋｇｆ／ｃｍ＾２）））を噴射して、余分なスラリーを除去する。
次いで、セル隔壁強化用スラリー２０をセル開口端面１１に含浸させたスラリー含浸体１０Ｂを、乾燥した後、コーディエライト相を生成、焼結できる所定条件にて焼成を行う。
セル開口端面１１から所定範囲Ｌ内のセル隔壁内に存在する空孔には、所定の粒径範囲に調整されたタルク粒子が含浸されている。
このため、焼成工程において、コーディエライト化原料のタルクリッチとなった部分の融点が降下し、緻密化が進むため、セル隔壁一般部１００に比べて５％程度、気孔率の低いセル隔壁強化部１１０が形成される。
このとき、本発明においては、粒径５０μｍ以上の粗大タルク粒子が除去されているので、過剰な融点降下を起こすことがなく、セル隔壁強化部１１０の表面に粗大空孔を生じ難くなっている。
以上により、図２（ｃ）に示すように、セル開口端面１１から所定の範囲Ｌにセル隔壁一般部１００より、気孔率が低く、表面粗さが粗い、セル隔壁強化部１１０が形成された本発明のハニカム構造体１０が形成される。
Next, as shown in FIG. 2 (b) impregnated with the cell partition wall reinforcing slurry 20, a predetermined pressure is compressed from the cell opening end portion 12 facing the cell opening end surface 11 impregnated with the cell partition wall reinforcing slurry 20. Air (for example, 0.2 kgf / cm ^ 2)) is injected to remove excess slurry.
Next, after the slurry impregnated body 10B in which the cell opening end face 11 is impregnated with the cell partition wall reinforcing slurry 20 is dried, the slurry is fired under predetermined conditions capable of generating and sintering a cordierite phase.
The pores existing in the cell partition walls within the predetermined range L from the cell opening end face 11 are impregnated with talc particles adjusted to a predetermined particle size range.
For this reason, in the firing step, the melting point of the talc rich portion of the cordierite-forming raw material is lowered and the densification proceeds, so that the cell partition wall reinforcement with a porosity of about 5% lower than the cell partition wall general part 100 is achieved. Part 110 is formed.
At this time, in the present invention, since coarse talc particles having a particle diameter of 50 μm or more are removed, excessive melting point drop does not occur, and coarse pores are hardly generated on the surface of the cell partition wall reinforced portion 110. .
As described above, as shown in FIG. 2C, the cell partition wall reinforced portion 110 having a lower porosity and a rougher surface roughness than the cell partition wall general portion 100 is formed in the predetermined range L from the cell opening end face 11. A honeycomb structure 10 of the present invention is formed.
なお、コーディエライト化原料としては、一般的に、Ｍｇ源、Ａｌ源、Ｓｉ源として知られる酸化物または水酸化物等の化合物を用いることができる。
具体的には、シリカ（ＳｉＯ２）、タルク（３ＭｇＯ・２ＳｉＯ２・Ｈ２Ｏ）、アルミナ（Ａｌ２Ｏ３）、水酸化アルミニウム（Ａｌ（ＯＨ）３）、カオリン（Ａｌ２Ｏ３・２ＳｉＯ２・２Ｈ２Ｏ）、蛇紋石（（Ｍｇ,Ｆｅ）３Ｓｉ２Ｏ５（ＯＨ）４）、パイロフェライト（Ａｌ２Ｓｉ４Ｏ１０（ＯＨ）２）、ブルーサイト（Ｍｇ（ＯＨ）２）等を出発原料として、焼成工程を経てコーディエライト相が生成される。
In addition, as a cordierite-forming raw material, compounds such as oxides or hydroxides generally known as Mg source, Al source, and Si source can be used.
Specifically, silica (SiO 2 ), talc (3MgO · 2SiO 2 · H 2 O), alumina (Al 2 O 3 ), aluminum hydroxide (Al (OH) 3 ), kaolin (Al 2 O 3 · 2SiO) 2 · 2H 2 O), serpentine ((Mg, Fe) 3 Si 2 O 5 (OH) 4), pyrophyllite (Al 2 Si 4 O 10 ( OH) 2), brucite (Mg (OH) 2) As a starting material, a cordierite phase is generated through a firing step.
ハニカム構造体１０を、触媒担体として用いる場合、ハニカム構造体１０に、Ｐｔ等の遷移金属触媒を分散させた触媒スラリーを含浸させ、触媒３０をセル隔壁１１０に担持させる。セル隔壁強化部１１０は、緻密化しており、触媒スラリーが含浸し難くなっているが本発明のハニカム構造体１０では、図２（ｃ）に示すように、一般部１００の表面粗さ（１０〜１５μｍＲｚｊｉｓ）に比べ、セル隔壁強化部１１０の表面粗さが粗くなっており（１２〜２１μｍＲｚｊｉｓ）、表面積が拡大されているので、セル隔壁一般部１００の触媒担持量とセル隔壁強化部１１０の触媒担持量とを、均一化することができる。
なお、ハニカム構造体の表面粗さは強化材料の平均粒子径、又は粒度分布を変更することで種々変えることができる。
When the honeycomb structure 10 is used as a catalyst carrier, the honeycomb structure 10 is impregnated with a catalyst slurry in which a transition metal catalyst such as Pt is dispersed, and the catalyst 30 is supported on the cell partition 110. The cell partition wall reinforcing portion 110 is densified and is difficult to impregnate with the catalyst slurry. However, in the honeycomb structure 10 of the present invention, as shown in FIG. 2 (c), the surface roughness (10 compared to ~15μmRz jis), the surface roughness of the cell partition wall reinforcing portions 110 is roughened (12~21μmRz jis), the surface area is enlarged, catalyst loading of the cell partition wall general portion 100 and the cell partition walls reinforced portion 110 catalyst loading can be made uniform.
The surface roughness of the honeycomb structure can be variously changed by changing the average particle size or particle size distribution of the reinforcing material.
ここで、図３に表面粗さと触媒担持量との関係についての具体的な実施例を示す。
図中○印は、気孔率３５％のセル隔壁一般部１００における表面粗さと触媒担持量との関係を示し、●印は、対応する実施例のセル隔壁強化部１１０における表面粗さと触媒担持量との関係を示す、△印は、セル隔壁一般部１００の気効率５０％である実施例における表面粗さと触媒担持量との関係を示し、▲印は、対応する実施例のセル隔壁強化部１１０における表面粗さと触媒担持量との関係を示す。
セル隔壁強化部１１０の気孔率は、セル隔壁一般部１００に比べて５％程度低くなっているが、表面粗さを荒くすることによって、セル隔壁一般部と同等の触媒担持量を確保することができる。
Here, FIG. 3 shows a specific example of the relationship between the surface roughness and the catalyst loading.
In the figure, ◯ indicates the relationship between the surface roughness and the catalyst loading in the cell partition wall general portion 100 having a porosity of 35%, and the ● indicates the surface roughness and the catalyst loading in the cell partition reinforcement 110 of the corresponding embodiment. The symbol Δ indicates the relationship between the surface roughness and the amount of catalyst supported in the example in which the cell partition general portion 100 has a gas efficiency of 50%, and the symbol ▲ indicates the cell partition reinforcing portion of the corresponding example. The relationship between the surface roughness at 110 and the catalyst loading is shown.
The porosity of the cell partition wall reinforced portion 110 is about 5% lower than that of the cell partition wall general portion 100, but by securing the surface roughness to ensure a catalyst loading equivalent to that of the cell partition wall general portion. Can do.
ここで、図４〜図６、表１〜３を参照して、本発明の効果を確認するために行った試験について説明する。
表１に示すように、水準１〜５について耐エロージョン性について調査を行った。
水準１では、セル隔壁強化用スラリーとして、５０μｍ以上の粗大タルク粒子を１２％含み、５μｍ以下の微細タルク粒子を３％含むタルク粉末をＡＦソルベントに濃度３０％で分散させたスラリーを用いてセル隔壁強化部を形成したハニカム構造体を作製し、サンプル数ｎ＝４について、耐エロージョン性を評価すべく、端面に対して、噴射圧：１．５ｋｇｆ／ｃｍ２、噴射時間：１分間、噴射物：球状シリカ（平均粒子径１００μｍ）、噴射距離：横１５０ｍｍ、高さ１５０ｍｍ、噴射角度：４５°（セル角方向から）の条件にてショットブラストを行い、その前後での重量変化量を測定し、エグレ量を比較し、評価した。
Here, with reference to FIGS. 4 to 6 and Tables 1 to 3, a test performed to confirm the effect of the present invention will be described.
As shown in Table 1, the erosion resistance was investigated for levels 1 to 5.
In Level 1, as a cell partition wall reinforcing slurry, a slurry in which talc powder containing 12% coarse talc particles of 50 μm or more and 3% fine talc particles of 5 μm or less is dispersed in an AF solvent at a concentration of 30% is used. A honeycomb structure in which partition wall reinforcing portions are formed is manufactured, and in order to evaluate the erosion resistance with respect to the number of samples n = 4, spray pressure: 1.5 kgf / cm 2 , spray time: 1 minute, spray on the end face Material: Spherical silica (average particle size 100 μm), spray distance: 150 mm wide, 150 mm high, shot angle: 45 ° (from cell angle direction), shot blasting, and measuring weight change before and after Then, the amount of aegle was compared and evaluated.
水準１は、従来の、セル隔壁強化部を有するハニカム構造体と同様の条件であり、これを比較例２とした。
水準２では、セル隔壁強化用スラリーとして、５０μｍ以上の粗大タルク粒子を１２％含み、５μｍ以下の微細タルク粒子を０．５％まで除去したタルク粉末をＡＦソルベントに濃度３０％で分散させたスラリーを用いてセル隔壁強化部を形成したハニカム構造体を作製し、水準１と同様にエグレ量を測定した。
水準２は、従来の同様の条件から微細タルク粒子を除去した場合の影響を確認するためのもので、これを比較例２とした。
水準３では、セル隔壁強化用スラリーとして、５０μｍ以上の粗大タルク粒子を０．２％まで除去し、５μｍ以下の微細タルク粒子を３．５５％含むタルク粉末をＡＦソルベントに濃度３０％で分散させたスラリーを用いてセル隔壁強化部を形成したハニカム構造体を作製し、水準１と同様にエグレ量を測定した。水準３は、本発明の効果を確認するためのもので、これを実施例１とした。
水準４では、セル隔壁強化用スラリーとして、５０μｍ以上の粗大タルク粒子を０．２％まで除去し、５μｍ以下の微細タルク粒子を０．５５％まで除去したタルク粉末をＡＦソルベントに濃度３０％で分散させたスラリーを用いてセル隔壁強化部を形成したハニカム構造体を作製し、水準１と同様にエグレ量を測定した。水準４は、本発明の効果及び、微細タルク粒子を除去した場合の影響を確認するためのもので、これを実施例２とした。
水準５では、従来のセル隔壁強化部を形成していないハニカム構造体のエグレ量を調査したもので、これを比較例１とした。
以上の条件で行った試験結果を表１及び、図４（ａ）、（ｂ）に示す。
評価結果として○印を付した比較例２は、比較例１に比べて、エグレ量が少なくなっており、セル隔壁強化部を設けた効果が見られるが、本発明の実施例１、２に比べれば効果は低い。
評価結果として○印を付した比較例３は、比較例１に比べて、エグレ量が少なくなっており、セル隔壁強化部を設けた効果が見られるが、比較例２と比べて、僅かであるが効果が低くなっている。これは、５μｍ以下の微細タルク粒子を除去した分、相対的に粒径が粗くなったためと推察される。
評価結果として◎印を付した実施例１は、最もエグレ量が少なくなっており、５０μｍ以上の粗大タルク粒子を除去することによってセル隔壁強化部の過剰な融点降下が抑制されたためと推察される。
評価結果として◎を付した実施例２は、実施例１とほぼ同様の効果が得られた。
以上の試験結果から、５０μｍ以上の粗大タルク粒子を除去することにより、セル隔壁強化部の耐エロージョン性が向上し、５μｍ以下の微細タルク粒子を除去することにより、耐エロージョン性はほとんど影響されないか、僅かに低下することが判明した。
Level 1 is the same condition as that of a conventional honeycomb structure having a cell partition wall reinforced portion, and this was designated as Comparative Example 2.
In Level 2, slurry for reinforcing the cell partition walls is a slurry obtained by dispersing talc powder containing 12% coarse talc particles of 50 μm or more and removing fine talc particles of 5 μm or less to 0.5% in an AF solvent at a concentration of 30%. A honeycomb structure in which the cell partition wall reinforced part was formed was prepared using the above, and the amount of aggression was measured in the same manner as in Level 1.
Level 2 is for confirming the influence when fine talc particles are removed under the same conditions as in the prior art.
Level 3 removes coarse talc particles of 50 μm or more to 0.2% as slurry for reinforcing the cell partition walls, and disperses talc powder containing 3.55% of fine talc particles of 5 μm or less in AF solvent at a concentration of 30%. A honeycomb structure in which the cell partition wall reinforced portion was formed using the slurry was prepared, and the amount of aggression was measured in the same manner as in Level 1. Level 3 is for confirming the effect of the present invention.
In Level 4, as the slurry for reinforcing the cell partition walls, coarse talc particles of 50 μm or more are removed to 0.2%, and talc powder from which fine talc particles of 5 μm or less are removed to 0.55% is added to the AF solvent at a concentration of 30%. A honeycomb structure in which the cell partition wall reinforced portion was formed was prepared using the dispersed slurry, and the amount of aggression was measured in the same manner as in Level 1. Level 4 is for confirming the effect of the present invention and the influence when fine talc particles are removed.
Level 5 was an investigation of the amount of glazing of the honeycomb structure in which the conventional cell partition wall reinforced portion was not formed. This was designated as Comparative Example 1.
The test results conducted under the above conditions are shown in Table 1 and FIGS. 4 (a) and 4 (b).
Comparative Example 2 marked with ○ as an evaluation result has a smaller amount of aggression than Comparative Example 1 and the effect of providing a cell partition wall reinforcing portion is seen. The effect is low compared.
Comparative Example 3 marked with ○ as an evaluation result has a small amount of aggression compared to Comparative Example 1, and an effect of providing a cell partition wall reinforcing portion is seen, but is slightly smaller than Comparative Example 2. Yes, but less effective. This is presumably because the particle diameter was relatively coarsened by removing fine talc particles of 5 μm or less.
In Example 1 marked with ◎ as the evaluation result, the amount of aggression was the smallest, and it is presumed that the excessive melting point drop of the cell partition wall reinforced portion was suppressed by removing coarse talc particles of 50 μm or more. .
Example 2 marked with “◎” as the evaluation result showed almost the same effect as Example 1.
From the above test results, by removing coarse talc particles of 50 μm or more, the erosion resistance of the cell partition reinforced portion is improved, and by removing fine talc particles of 5 μm or less, the erosion resistance is hardly affected. It was found to decrease slightly.
表２及び図５を参照して、セル隔壁強化用スラリー作製の作業性向上を図るために行った試験結果について説明する。
水準６〜水準９の条件でタルク粉末の粒度を調整し、分散媒に投入し、自然沈降させ、完全分散するまでに要した時間を計測した結果を表２及び図４に示す。
水準６では、２μｍ以下の微細タルク粒子を除去し、これを実施例４とした。
水準７では、３μｍ以下の微細タルク粒子を除去し、これを実施例５とした。水準８では、５μｍ以下の微細タルク粒子を除去し、これを実施例６とした。水準９では、８μｍ以下の微細タルク粒子を除去し、これを実施例７とした。
なお、各水準において、これらの微細タルク粒子は気流分級機を用いて除去したため、厳密にいえば完全に除去されていない微細タルク粒子を含むが、スラリー中の含有率が０．５％以下であれば作業性に影響なきレベルであり「除去した」といえる。
表２及び図５に示すように、微細タルク粒子を除去することにより、沈降時間が短くなり、完全分散に要する時間の短縮を図ることができると推察されるが、５μｍ以下の微細タルク粒子を除去するのが最も効果的で、８μｍ以下の微細タルク粒子を除去しても作業時間の短縮効果は頭打ちとなる。
一方、微細タルク粒子を除去し過ぎると、上述の如く耐エロージョン性が悪化する虞がある。
そこで、作業時間の短縮を図りつつ、耐エロージョン性を向上させるためには、５０μｍ以上の粗大タルク粒子を除去し、５μｍ以下の微細タルク粒子を除去するのが望ましいことが判明した。
Table 2 and FIG. 4 show the results of measuring the time required to adjust the particle size of talc powder under the conditions of level 6 to level 9, put into a dispersion medium, naturally settle, and completely disperse.
In level 6, fine talc particles of 2 μm or less were removed, and this was designated as Example 4.
In level 7, fine talc particles of 3 μm or less were removed, and this was designated as Example 5. At level 8, fine talc particles of 5 μm or less were removed, and this was designated as Example 6. At level 9, fine talc particles of 8 μm or less were removed, and this was designated as Example 7.
In each level, since these fine talc particles were removed using an air classifier, strictly speaking, they contain fine talc particles that have not been completely removed, but the content in the slurry is 0.5% or less. If it exists, it is a level that does not affect workability and can be said to be “removed”.
As shown in Table 2 and FIG. 5, it is surmised that by removing fine talc particles, the sedimentation time is shortened and the time required for complete dispersion can be shortened. It is most effective to remove, and even if fine talc particles of 8 μm or less are removed, the effect of shortening the working time reaches its peak.
On the other hand, if the fine talc particles are removed excessively, the erosion resistance may deteriorate as described above.
Thus, it has been found that it is desirable to remove coarse talc particles of 50 μm or more and fine talc particles of 5 μm or less in order to improve erosion resistance while shortening the working time.
表３及び図４を参照して、粗大タルク粒子の影響について調査した結果について説明する。
水準１０は、３８μｍ以上粗大タルク粒子を除いた３８μｍより小さいタルク粒子のみからなるセル隔壁強化用スラリーを含浸させたハニカム構造体を作製し、粗大空孔の有無を確認した結果であり、これを比較例４とした。
水準１１は、４５μｍ以上の粗大タルク粒子を除いた４５μｍより小さい粗大タルク粒子のみからなるセル隔壁強化用スラリーを含浸させたハニカム構造体を作製し、粗大空孔の有無を確認した結果であり、これを比較例５とした。
水準１２は、５３μｍ以上の粗大タルク粒子を除いた５３μｍより小さいタルク粒子のみからなるセル隔壁強化用スラリーを含浸させたハニカム構造体を作製し、粗大空孔の有無を確認した結果であり、これを実施例8とした。
水準１２は、６３μｍ以上の粗大タルク粒子を除いたセル隔壁強化用スラリーを含浸させたハニカム構造体を作製し、粗大空孔の有無を確認した結果であり、これを比較例6とした。実施例8は上述の実施例１に相当する。
図６（ｂ）、（ｃ）は、それぞれ、比較例６のハニカム構造体１ｚ及び実施例８のハニカム構造体１のセル隔壁強化部（１１０ｚ、１１０）及びセル隔壁一般部（１００ｚ、１００）を、図６（ａ）に示す方向から観察した電子顕微鏡写真である。
比較例４〜５、実施例8には図６（ｂ）に示すような１００μｍ以上の大きさの粗大空孔は全く観察されなかったが、比較例６には、図６（ｃ）に示すように、１００μｍ以上の大きな粗大空孔が１セル当たりに１ないし複数個観察された。
なお、セル隔壁強化用スラリーを含浸させる前の乾燥体１０Ａのセル開口端面１１近傍のセル隔壁１００には、図６（ｂ）に示すような粗大空孔は全く存在せず、これらの粗大空孔は、明らかに、従来の５０μｍ以上の粗大タルク粒子を除去していないセル隔壁強化用スラリーを含浸させて焼成したことにより発生したものである。
Level 10 is the result of producing a honeycomb structure impregnated with a slurry for reinforcing cell partition walls composed only of talc particles smaller than 38 μm excluding coarse talc particles of 38 μm or more, and confirming the presence or absence of coarse pores. It was set as Comparative Example 4.
Level 11 is a result of producing a honeycomb structure impregnated with a slurry for reinforcing cell partition walls composed only of coarse talc particles smaller than 45 μm excluding coarse talc particles of 45 μm or more, and confirming the presence or absence of coarse pores, This was designated as Comparative Example 5.
Level 12 is a result of producing a honeycomb structure impregnated with a slurry for reinforcing a cell partition made of only talc particles smaller than 53 μm excluding coarse talc particles of 53 μm or more, and confirming the presence or absence of coarse pores. This was taken as Example 8.
Level 12 is a result of producing a honeycomb structure impregnated with slurry for reinforcing cell partition walls excluding coarse talc particles of 63 μm or more and confirming the presence or absence of coarse pores. Example 8 corresponds to Example 1 described above.
6 (b) and 6 (c) respectively show the honeycomb structure 1z of the comparative example 6 and the cell partition reinforcing portion (110z, 110) and the cell partition general portion (100z, 100) of the honeycomb structure 1 of Example 8. It is the electron micrograph which observed this from the direction shown to Fig.6 (a).
In Comparative Examples 4 to 5 and Example 8, coarse pores having a size of 100 μm or more as shown in FIG. 6B were not observed at all. In Comparative Example 6, FIG. Thus, one or more large pores of 100 μm or more were observed per cell.
Note that the cell partition wall 100 in the vicinity of the cell opening end face 11 of the dried body 10A before impregnating the cell partition wall reinforcing slurry does not have any coarse pores as shown in FIG. The pores are apparently generated by impregnating and firing the slurry for reinforcing the cell partition walls from which the conventional coarse talc particles of 50 μm or more have not been removed.
本発明は、上記実施形態に限定するものではなく、セル隔壁強化用スラリーを作製するに際して５μｍ以下の微細タルク粒子を除去して、分散時間を短縮して作業性を向上すると共に、５０μｍ以上の粗大タルク粒子を除去して、コーディエライトの過剰な融点降下を抑制しつつ、セル隔壁強化部を形成して耐久性に優れたハニカム構造体を提供する本発明の趣旨を逸脱しない限りにおいて適宜変更し得るものである。
例えば、上記実施形態においては、ハニカム構造体の一方のセル開口端壁にセル隔壁強化部を設けた例について説明したが、両端にセル隔壁強化部を設けても良い。
また、上記実施形態においては、ハニカム構造体の両端が開口するいわゆる、ウオールフロータイプのハニカム構造体を例として説明したが、セル開口が交互に目封止された、いわゆるウオールスルータイプのハニカム構造体においても適宜採用し得るものである。また、上記実施形態においては、ハニカム構造体に触媒を担持させて排ガス浄化フィルタに用いた例について説明したが、本発明のハニカム構造体は、触媒担体のみならず、ＤＰＦその他のハニカム構造体全般に適用し得るものである。
本発明は、コーディエライト質のハニカム構造体に特に効果を発揮するものであるが、低融点化材料を含浸させてハニカム構造体のセル開口端面付近のセル隔壁を緻密化させて、耐エロージョン性の向上を図ることができるものであれば、低融点化材料の粒径を特定の範囲に調整することにより局所的な溶損を防止しして更なる耐エロージョン性の向上を図ろうとする本発明の思想は、コーディエライト質以外のハニカム構造体の製造にも適用し得るものである。
The present invention is not limited to the above embodiment, and when producing a slurry for reinforcing a cell partition wall, fine talc particles of 5 μm or less are removed, the dispersion time is shortened, workability is improved, and 50 μm or more is improved. As long as it does not depart from the gist of the present invention to remove the coarse talc particles and suppress the excessive melting point fall of cordierite and to form the cell partition reinforced portion to provide a honeycomb structure excellent in durability. It can be changed.
For example, in the above-described embodiment, the example in which the cell partition wall reinforcing portion is provided on one cell opening end wall of the honeycomb structure has been described, but the cell partition wall reinforcing portion may be provided at both ends.
Further, in the above embodiment, a so-called wall flow type honeycomb structure in which both ends of the honeycomb structure are opened has been described as an example, but a so-called wall through type honeycomb structure in which cell openings are alternately plugged is described. It can also be appropriately employed in the body. Further, in the above-described embodiment, the example in which the catalyst is supported on the honeycomb structure and used for the exhaust gas purification filter has been described. However, the honeycomb structure of the present invention is not only a catalyst carrier but also DPF and other honeycomb structures in general. It can be applied to.
The present invention is particularly effective for cordierite honeycomb structures, but is impregnated with a material having a low melting point so as to densify the cell partition walls in the vicinity of the cell opening end faces of the honeycomb structure, thereby preventing erosion. If it is possible to improve the property, the particle size of the low melting point material is adjusted to a specific range to prevent local melting damage and further improve the erosion resistance. The idea of the present invention can also be applied to the manufacture of honeycomb structures other than cordierite.
１ 排ガス浄化用触媒
１０ ハニカム構造体
１１、１２ セル開口端面
１０１ セル
１００ セル隔壁一般部（非強化部）
１１０ セル隔壁強化部
１２０ 基体外皮部
２０ セル開口端部壁強化用スラリー
３０ 触媒
DESCRIPTION OF SYMBOLS 1 Exhaust gas purification catalyst 10 Honeycomb structure 11, 12 Cell opening end surface 101 Cell 100 Cell partition wall general part (non-reinforced part)
110 Cell partition wall reinforcing portion 120 Base shell portion 20 Cell opening end wall reinforcing slurry 30 Catalyst
Claims (6)
上記セル隔壁強化部にガス流れに垂直な方向から観察したとき１００μｍ以上の粗大空孔が実質存在しないことを特徴とするハニカム構造体。 A honeycomb structure in which a plurality of cells partitioned into cell partition walls made of cordierite material are arranged to form a honeycomb shape, or a porosity within a predetermined range from the opening end surfaces of both, is lower than the general portion of the cell partition walls In the honeycomb structure provided with the cell partition reinforcement part,
A honeycomb structure characterized by substantially not having coarse pores of 100 μm or more when observed from a direction perpendicular to the gas flow in the cell partition wall reinforced portion.
上記セル隔壁強化材料の主原料粒子から、所定の粒径以上の粗大粒子を除去して上記セル隔壁強化用スラリーを作製することを特徴とするハニカム構造体の製造方法。 A plurality of cells partitioned into cell partition walls made of cordierite material are arranged to impregnate one or both open ends of the honeycomb structure with a cell partition reinforcement slurry containing cell partition wall reinforcing material. In the method for manufacturing a honeycomb structure for forming a cell partition reinforcing portion having a lower porosity than the cell partition general portion,
A method for manufacturing a honeycomb structured body, wherein coarse particles having a predetermined particle diameter or more are removed from main raw material particles of the cell partition wall reinforcing material to produce the cell partition wall reinforcing slurry.
The method for manufacturing a honeycomb structure according to claim 4 or 5, wherein the cell partition wall reinforcing material is talc powder that lowers the melting point of cordierite, and coarse talc particles of 50 µm or more are removed as the coarse particles.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013129630A1 (en) | 2012-03-01 | 2013-09-06 | 株式会社ブリヂストン | Tire |
| WO2021020101A1 (en) * | 2019-07-31 | 2021-02-04 | 株式会社デンソー | Exhaust gas purification filter |
| WO2021020100A1 (en) * | 2019-07-31 | 2021-02-04 | 株式会社デンソー | Exhaust gas purification filter |
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2010
- 2010-08-30 JP JP2010192438A patent/JP2012045523A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013129630A1 (en) | 2012-03-01 | 2013-09-06 | 株式会社ブリヂストン | Tire |
| WO2021020101A1 (en) * | 2019-07-31 | 2021-02-04 | 株式会社デンソー | Exhaust gas purification filter |
| WO2021020100A1 (en) * | 2019-07-31 | 2021-02-04 | 株式会社デンソー | Exhaust gas purification filter |
| JP2021023848A (en) * | 2019-07-31 | 2021-02-22 | 株式会社デンソー | Exhaust gas purification filter |
| JP2021023847A (en) * | 2019-07-31 | 2021-02-22 | 株式会社デンソー | Exhaust gas purification filter |
| CN113490786A (en) * | 2019-07-31 | 2021-10-08 | 株式会社电装 | Exhaust gas purifying filter |
| CN113646511A (en) * | 2019-07-31 | 2021-11-12 | 株式会社电装 | Exhaust gas purifying filter |
| CN113490786B (en) * | 2019-07-31 | 2022-05-17 | 株式会社电装 | Exhaust gas purifying filter |
| CN113646511B (en) * | 2019-07-31 | 2022-06-24 | 株式会社电装 | Exhaust gas purifying filter |
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