JP2003321280A - Honeycomb structure, method for producing the same, and diesel particulate filter - Google Patents
Honeycomb structure, method for producing the same, and diesel particulate filterInfo
- Publication number
- JP2003321280A JP2003321280A JP2002126099A JP2002126099A JP2003321280A JP 2003321280 A JP2003321280 A JP 2003321280A JP 2002126099 A JP2002126099 A JP 2002126099A JP 2002126099 A JP2002126099 A JP 2002126099A JP 2003321280 A JP2003321280 A JP 2003321280A
- Authority
- JP
- Japan
- Prior art keywords
- honeycomb structure
- pores
- dpf
- cells
- oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000011148 porous material Substances 0.000 claims abstract description 51
- 238000005192 partition Methods 0.000 claims abstract description 37
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 28
- 229910052878 cordierite Inorganic materials 0.000 claims abstract description 18
- 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 18
- 229910052581 Si3N4 Inorganic materials 0.000 claims abstract description 9
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000000758 substrate Substances 0.000 claims description 23
- 125000005372 silanol group Chemical group 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 15
- 229910000510 noble metal Inorganic materials 0.000 claims description 15
- 239000003054 catalyst Substances 0.000 claims description 13
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 3
- 238000005121 nitriding Methods 0.000 claims description 3
- 230000008646 thermal stress Effects 0.000 abstract description 6
- 230000004927 fusion Effects 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 21
- 239000000843 powder Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 239000002585 base Substances 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- 239000011232 storage material Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000008929 regeneration Effects 0.000 description 4
- 238000011069 regeneration method Methods 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 150000004820 halides Chemical class 0.000 description 3
- 150000004678 hydrides Chemical class 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000010970 precious metal Substances 0.000 description 3
- 125000005373 siloxane group Chemical group [SiH2](O*)* 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 2
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 2
- 238000010574 gas phase reaction Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 101100325793 Arabidopsis thaliana BCA2 gene Proteins 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 102100029777 Eukaryotic translation initiation factor 3 subunit M Human genes 0.000 description 1
- 101001012700 Homo sapiens Eukaryotic translation initiation factor 3 subunit M Proteins 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 229910052792 caesium Inorganic materials 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000003961 organosilicon compounds Chemical class 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052706 scandium Inorganic materials 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Landscapes
- Filtering Materials (AREA)
- Exhaust Gas After Treatment (AREA)
- Processes For Solid Components From Exhaust (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Porous Artificial Stone Or Porous Ceramic Products (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、自動車の排ガス浄
化用触媒あるいはディーゼルパティキュレートフィルタ
（以下ＤＰＦという）として用いられるハニカム構造体
とその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honeycomb structure used as an exhaust gas purifying catalyst for automobiles or a diesel particulate filter (hereinafter referred to as DPF), and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】ガソリンエンジンについては、排ガスの
厳しい規制とそれに対処できる技術の進歩とにより、排
ガス中の有害成分は確実に減少している。しかし、ディ
ーゼルエンジンについては、有害成分がＰＭとして排出
されるという特異な事情から、規制も技術の進歩もガソ
リンエンジンに比べて遅れている。2. Description of the Related Art With regard to gasoline engines, harmful regulations in exhaust gas have been steadily reduced due to strict regulations on exhaust gas and progress in technology capable of coping with the regulations. However, with respect to diesel engines, regulations and technological progress are delayed compared to gasoline engines due to the unique circumstances in which harmful components are emitted as PM.
【０００３】現在までに開発されているディーゼルエン
ジン用排ガス浄化装置としては、大きく分けてトラップ
型の排ガス浄化装置と、オープン型の排ガス浄化装置と
が知られている。このうちトラップ型の排ガス浄化装置
としては、コーディエライトなどのセラミック製の目封
じタイプのＤＰＦが知られている。このＤＰＦは、セラ
ミックハニカム構造体の複数のセルが、排ガス下流端が
目詰めされた流入側セルと、流入側セルに隣接し排ガス
上流端が目詰めされた流出側セルと、からなる複数のセ
ルをもつものであり、セル隔壁の細孔で排ガスを濾過し
てセル隔壁にＰＭを捕集することで排出を抑制するいわ
ゆるウォールフロー型のものである。As exhaust gas purifying apparatuses for diesel engines that have been developed to date, there are roughly classified a trap type exhaust gas purifying apparatus and an open type exhaust gas purifying apparatus. Among these, as a trap type exhaust gas purifying device, a plugging type DPF made of ceramic such as cordierite is known. In this DPF, a plurality of cells of a ceramic honeycomb structure are composed of an inflow side cell in which the exhaust gas downstream end is clogged, and an outflow side cell adjacent to the inflow side cell and in which the exhaust gas upstream end is clogged. It has a cell and is a so-called wall flow type in which exhaust gas is filtered through the pores of the cell partition wall and PM is collected in the cell partition wall to suppress discharge.
【０００４】しかしＤＰＦでは、ＰＭの堆積によって圧
損が上昇するため、何らかの手段で堆積したＰＭを定期
的に除去して再生する必要がある。そこで従来は、圧損
が上昇した場合にバーナや電気ヒータ等で加熱して、あ
るいは高温の排ガスを供給して、堆積したＰＭを燃焼さ
せることでＤＰＦを再生することが行われている。しか
しながらこの場合には、ＰＭの堆積量が多いほど燃焼時
の温度が上昇し、それによってＤＰＦが溶損する場合も
ある。However, in the DPF, since the pressure loss increases due to the accumulation of PM, it is necessary to periodically remove and regenerate the PM accumulated by some means. Therefore, conventionally, when the pressure loss increases, the DPF is regenerated by heating with a burner, an electric heater, or the like, or by supplying high-temperature exhaust gas to burn the accumulated PM. However, in this case, the temperature at the time of combustion rises as the amount of PM deposited increases, which may cause the DPF to melt.
【０００５】そこで近年では、ＤＰＦのセル隔壁にアル
ミナなどからコート層を形成し、そのコート層に白金族
貴金属などを担持した連続再生式ＤＰＦが開発されてい
る。この連続再生式ＤＰＦによれば、セル隔壁の細孔中
に捕集されたＰＭが貴金属の触媒活性によって酸化燃焼
するため、捕集と同時にあるいは捕集に連続して燃焼さ
せることでＤＰＦを再生することができる。そして触媒
活性は比較的低温で生じること、及び捕集量が少ないう
ちに燃焼できることから、ＤＰＦに作用する熱応力が小
さく破損が防止されるという利点がある。Therefore, in recent years, a continuous regeneration type DPF has been developed in which a coat layer is formed from alumina or the like on the cell partition wall of the DPF and a platinum group precious metal or the like is carried on the coat layer. According to this continuous regeneration type DPF, the PM trapped in the pores of the cell partition wall is oxidized and burned by the catalytic activity of the noble metal, so that the DPF is regenerated by burning it at the same time as the trapping or continuously in the trapping. can do. Since the catalytic activity is generated at a relatively low temperature and the catalyst can be burned while the trapped amount is small, there is an advantage that the thermal stress acting on the DPF is small and damage is prevented.
【０００６】ところが連続再生式ＤＰＦにおいても、低
温時には貴金属の活性が発現されないために、低温域で
ＰＭがセル隔壁に堆積し、高温となった時点で一気に燃
焼するという現象がある。このような場合には、コーデ
ィエライトなどから形成されたＤＰＦでは、熱応力によ
ってクラックが生じる場合があった。この原因は以下の
ように考えられている。However, even in the continuous regeneration type DPF, since the activity of the noble metal is not expressed at a low temperature, there is a phenomenon that PM is deposited on the cell partition wall in a low temperature region and burns at a high temperature at a stretch. In such a case, the DPF formed of cordierite or the like may have cracks due to thermal stress. The cause of this is considered as follows.
【０００７】堆積したＰＭの燃焼は、ＤＰＦ全体で一様
に起こるわけではなく、先ず温度が最も高くなった部分
から燃焼しその燃焼が伝播する。また微視的にも燃焼部
と非燃焼部で温度差が生じる。しかしコーディエライト
は熱伝導性が低いために温度差が大きい部分が生じ、熱
応力によってクラックが生じるのである。The combustion of the deposited PM does not occur uniformly in the entire DPF, but the combustion is propagated from the part where the temperature is highest first. Microscopically, there is a temperature difference between the burning part and the non-burning part. However, cordierite has a low thermal conductivity, so that a portion with a large temperature difference is generated, and cracks are generated by thermal stress.
【０００８】一方、炭化ケイ素はコーディエライトより
熱伝導性に優れているので、炭化ケイ素製のＤＰＦを用
いれば熱応力によるクラックの発生を防止することがで
きる。しかし炭化ケイ素は嵩密度が高いために、重いＤ
ＰＦとなり近年の自動車の軽量化の動きに逆行してしま
う。また炭化ケイ素はコストが高いのでＤＰＦも高価と
なり、そしてＤＰＦとしての実績もなく、連続再生式Ｄ
ＰＦとするための細孔径の制御も難しいと考えられる。On the other hand, since silicon carbide has a higher thermal conductivity than cordierite, the use of a silicon carbide DPF can prevent the occurrence of cracks due to thermal stress. However, since silicon carbide has a high bulk density, heavy D
It becomes a PF and goes against the recent trend toward weight reduction of automobiles. Moreover, since the cost of silicon carbide is high, the DPF becomes expensive, and there is no record as a DPF.
It is considered that it is difficult to control the pore size to obtain PF.
【０００９】[0009]
【発明が解決しようとする課題】本発明はこのような事
情に鑑みてなされたものであり、軽量で熱伝導性に優れ
たハニカム構造体とすることで、ＤＰＦとしたときに溶
損やクラックの発生を抑制することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and by forming a honeycomb structure which is lightweight and has excellent thermal conductivity, it is possible to prevent melting damage and cracks in a DPF. The purpose is to suppress the occurrence of.
【００１０】[0010]
【課題を解決するための手段】上記課題を解決する本発
明のハニカム構造体の特徴は、酸化物よりなり複数のセ
ルを有して該セルの隔壁に気体が流通可能な細孔をもつ
ハニカム構造体であって、少なくとも一部の細孔の表面
には炭化ケイ素又は窒化ケイ素から選ばれる少なくとも
一種からなる熱伝導層をもつことにある。The honeycomb structure of the present invention for solving the above-mentioned problems is characterized in that it is made of an oxide and has a plurality of cells, and the partition walls of the cells have pores through which a gas can flow. The structure is to have a heat conductive layer made of at least one selected from silicon carbide and silicon nitride on the surface of at least some of the pores.
【００１１】また本発明のハニカム構造体を製造できる
製造方法の特徴は、酸化物よりなり複数のセルを有して
セルの隔壁に気体が流通可能な細孔をもつハニカム基材
の少なくとも一部の細孔の表面にシラノール基を形成す
るシラノール処理を行い、次いで少なくとも炭素を含む
還元雰囲気中で熱処理することにある。Further, the manufacturing method capable of manufacturing the honeycomb structure of the present invention is characterized in that at least a part of a honeycomb substrate made of an oxide and having a plurality of cells and having pores through which gas can flow in the partition walls of the cells. Silanol treatment for forming silanol groups is performed on the surface of the pores, and then heat treatment is performed in a reducing atmosphere containing at least carbon.
【００１２】本発明のハニカム構造体を製造できるもう
一つの製造方法の特徴は、酸化物よりなり複数のセルを
有してセルの隔壁に気体が流通可能な細孔をもつハニカ
ム基材の少なくとも一部の細孔の表面にシラノール基を
形成するシラノール処理を行い、次いで窒化処理するこ
とにある。Another feature of the method for producing the honeycomb structure of the present invention is that it has at least a honeycomb substrate made of an oxide and having a plurality of cells and having pores through which gas can flow in the partition walls of the cells. This is to perform silanol treatment for forming silanol groups on the surface of some pores, and then perform nitriding treatment.
【００１３】そして本発明のＤＰＦの特徴は、本発明の
ハニカム構造体からなり、複数のセルは、排ガス下流端
が目詰めされた流入側セルと、流入側セルに隣接し排ガ
ス上流端が目詰めされた流出側セルと、からなることに
ある。流入側セルと流出側セルを区画する隔壁の細孔の
最表面には、多孔質酸化物と貴金属を含む触媒層をもつ
ことが望ましい。A feature of the DPF of the present invention is that the honeycomb structure of the present invention is used, and a plurality of cells are provided with an inlet side cell having a closed exhaust gas downstream end and an exhaust gas upstream end adjacent to the inlet side cell. And the packed outflow side cell. It is desirable to have a catalyst layer containing a porous oxide and a noble metal on the outermost surface of the pores of the partition walls that partition the inflow side cell and the outflow side cell.
【００１４】[0014]
【発明の実施の形態】本発明のハニカム構造体では、少
なくとも一部の細孔の表面に炭化ケイ素又は窒化ケイ素
から選ばれる少なくとも一種からなる熱伝導層が形成さ
れている。炭化ケイ素又は窒化ケイ素は熱伝導性が高い
ので、ＰＭの燃焼による熱は熱伝導層を通じて速やかに
拡散され、温度差が小さくなるため熱応力によるクラッ
クの発生が抑制される。そして熱伝導層は細孔の表面に
のみ形成され、大部分はコーディエライトなどの酸化物
から形成されているので、全体としての嵩密度を低くす
ることができ軽量とすることができる。またコーディエ
ライトなどの酸化物は安価であるとともにセル隔壁の細
孔径の制御も容易であり、ＤＰＦとしての特性を容易に
満足させることができる。BEST MODE FOR CARRYING OUT THE INVENTION In the honeycomb structure of the present invention, a heat conducting layer made of at least one selected from silicon carbide and silicon nitride is formed on the surface of at least some of the pores. Since silicon carbide or silicon nitride has high thermal conductivity, the heat generated by burning PM is quickly diffused through the thermal conductive layer, and the temperature difference is reduced, so that the generation of cracks due to thermal stress is suppressed. Further, since the heat conduction layer is formed only on the surface of the pores and most of it is formed of an oxide such as cordierite, the bulk density as a whole can be lowered and the weight can be reduced. Further, oxides such as cordierite are inexpensive, and the pore size of the cell partition walls can be easily controlled, so that the characteristics as a DPF can be easily satisfied.
【００１５】本発明のハニカム構造体は、酸化物よりな
るハニカム基材と、その隔壁の細孔表面に形成された熱
伝導層と、から構成される。ハニカム基材は従来のＤＰ
Ｆに用いられているハニカム基材と同様のものであり、
アルミナ、ジルコニア、セリア、チタニア、シリカ、シ
リカ−アルミナ、コーディエライトなど公知の酸化物か
ら製造されたものを用いることができる。中でも実績の
あるコーディエライトが特に好ましい。ハニカム構造体
の大きさ、セル密度などは用途に応じて選択することが
できる。またセル隔壁の気孔率が60〜80％であることが
望ましく、セル隔壁の平均細孔径が20〜40μｍであるこ
とが望ましい。気孔率が60％より低かったり平均細孔径
が20μｍより小さいと圧損が増大し、気孔率が80％を超
えたり平均細孔径が40μｍより大きくなるとＰＭ捕集率
が低下する。The honeycomb structure of the present invention comprises a honeycomb base material made of an oxide and a heat conduction layer formed on the pore surface of the partition walls. The conventional honeycomb substrate is DP
It is similar to the honeycomb substrate used for F,
It is possible to use those manufactured from known oxides such as alumina, zirconia, ceria, titania, silica, silica-alumina, and cordierite. Of these, proven cordierite is particularly preferable. The size and cell density of the honeycomb structure can be selected according to the application. Further, the porosity of the cell partition wall is preferably 60 to 80%, and the average pore diameter of the cell partition wall is preferably 20 to 40 μm. If the porosity is lower than 60% or the average pore diameter is less than 20 μm, the pressure loss increases, and if the porosity exceeds 80% or the average pore diameter exceeds 40 μm, the PM trapping rate decreases.
【００１６】ハニカム基材を製造するには、コーディエ
ライトなどの酸化物粉末に所定粒径のカーボン粉末，木
粉，澱粉，樹脂粉末などの可燃性粉末を混合し、バイン
ダーと共に粘土状のスラリーとする。そして押出成形な
どによってハニカム形状に成形し、それを焼成すること
で隔壁に細孔をもつハニカム基材を製造することができ
る。To manufacture a honeycomb substrate, an oxide powder such as cordierite is mixed with a combustible powder such as carbon powder, wood powder, starch, or resin powder having a predetermined particle diameter, and a clay-like slurry with a binder. And Then, a honeycomb base material having pores in partition walls can be manufactured by forming it into a honeycomb shape by extrusion molding or the like and firing it.
【００１７】熱伝導層は、炭化ケイ素又は窒化ケイ素か
ら選ばれる少なくとも一種から形成されている。炭化ケ
イ素又は窒化ケイ素のいずれか一方のみから形成しても
よいし、場合によっては両者の併用も可能である。また
熱伝導層にアルミナなどの酸化物が含まれていても特に
不具合は生じないが、このような不純物の含有量は25重
量％以内に制限されるべきである。この熱伝導層は、セ
ル隔壁の少なくとも一部の細孔の表面に形成されていれ
ばそれなりの効果が発現されるが、セル隔壁の全ての細
孔の表面に形成されていることが望ましい。The heat conducting layer is formed of at least one selected from silicon carbide and silicon nitride. It may be formed from only one of silicon carbide and silicon nitride, or may be used in combination depending on the case. Even if the heat conducting layer contains an oxide such as alumina, no particular problems occur, but the content of such impurities should be limited to within 25% by weight. The heat conducting layer has some effect if it is formed on the surface of at least a part of the pores of the cell partition wall, but it is preferable that it is formed on the surface of all the pores of the cell partition wall.
【００１８】また熱伝導層は、厚くなるほど熱伝導性が
向上するが、あまり厚くしすぎると通気抵抗が増大して
圧損が増大するという不具合が生じる。したがって、細
孔径あるいは細孔分布などにもよるが、熱伝導層の厚さ
は0.01〜１μｍ（又はハニカム基材１リットルあたり１
〜50ｇ）とするのが好ましい。Further, the heat conductivity of the heat conductive layer is improved as the thickness thereof is increased. However, if the heat conductive layer is excessively thick, the ventilation resistance increases and the pressure loss increases. Therefore, the thickness of the heat conduction layer is 0.01 to 1 μm (or 1 per 1 liter of the honeycomb substrate), though it depends on the pore diameter or the pore distribution.
~ 50g) is preferred.
【００１９】ハニカム基材の細孔表面に熱伝導層を形成
するには、物理的薄膜形成法（ PVD法），化学的薄膜形
成法（ CVD法），超臨界流体を利用する方法などを利用
して、細孔表面にシラノール基を生成させ、それを炭化
処理又は窒化処理することで行うことができる。また細
孔表面にSiO2層を形成し、それを炭化又は窒化すること
で形成することもできる。To form the heat conduction layer on the pore surface of the honeycomb substrate, a physical thin film forming method (PVD method), a chemical thin film forming method (CVD method), a method using a supercritical fluid, etc. are used. Then, silanol groups are generated on the surface of the pores, and the silanol groups are carbonized or nitrided. It can also be formed by forming a SiO 2 layer on the surface of the pores and carbonizing or nitriding it.
【００２０】例えば炭化ケイ素からなる熱伝導層を形成
するには、 CVD法などによって細孔表面にシラノール基
あるいはシロキサン基を生成させ、それをカーボンによ
って還元することで形成する方法がある。またSiのハロ
ゲン化物あるいは水素化物と炭化水素との気相反応によ
って形成する方法、あるいは有機ケイ素化合物の熱分解
反応によって形成する方法などを利用することも可能で
ある。For example, in order to form a heat conductive layer made of silicon carbide, there is a method of forming a silanol group or a siloxane group on the surface of pores by a CVD method or the like and reducing the silanol group or siloxane group with carbon. It is also possible to use a method of forming by a gas phase reaction of a halide or hydride of Si and a hydrocarbon, a method of forming by a thermal decomposition reaction of an organosilicon compound, or the like.
【００２１】また窒化ケイ素からなる熱伝導層を形成す
るには、 CVD法などによって細孔表面にシラノール基あ
るいはシロキサン基を生成させ、それをカーボンと共に
窒素ガス中で加熱する還元・窒化法がある。またSiのハ
ロゲン化物あるいは水素化物とアンモニアとの気相反応
によって形成する方法、あるいはSiのハロゲン化物又は
水素化物とアンモニアとを室温以下で合成した中間生成
物を高温に加熱して分解する熱分解法などを利用するこ
とも可能である。In order to form the heat conduction layer made of silicon nitride, there is a reduction / nitridation method in which a silanol group or a siloxane group is generated on the surface of the pores by the CVD method or the like and heated in nitrogen gas together with carbon. . Further, a method of forming by a gas phase reaction between a halide or hydride of Si and ammonia, or a thermal decomposition in which an intermediate product obtained by synthesizing a halide or hydride of Si and ammonia at room temperature or lower is heated to a high temperature and decomposed. It is also possible to use the law.
【００２２】なお、コーディエライトなどの酸化物粉末
の表面を炭化ケイ素又は窒化ケイ素で覆い、この二層構
造の粉末を用いてハニカム構造体を形成することも可能
である。この場合は、上記と同様にしてハニカム基材を
形成すれば、形成された細孔の表面には熱伝導層が形成
される。It is also possible to cover the surface of an oxide powder such as cordierite with silicon carbide or silicon nitride and use this double-layered powder to form a honeycomb structure. In this case, if the honeycomb substrate is formed in the same manner as described above, the heat conduction layer is formed on the surface of the formed pores.
【００２３】また本発明のＤＰＦを製造するには、本発
明のハニカム構造体を用い、排ガス下流端を目詰めして
流入側セルを形成するとともに、流入側セルに隣接する
セルの排ガス上流端を目詰めして流出側セルを形成す
る。目詰め材としては、ハニカム基材と同じ材質のコー
ディエライトなどの粉末を用いることが望ましい。Further, in order to manufacture the DPF of the present invention, the honeycomb structure of the present invention is used, and the exhaust gas downstream end is clogged to form the inflow side cell, and the exhaust gas upstream end of the cell adjacent to the inflow side cell is formed. To form an outflow side cell. As the filling material, it is desirable to use powder such as cordierite, which is the same material as the honeycomb substrate.
【００２４】本発明のＤＰＦは、流入側セルと流出側セ
ルを区画する隔壁の細孔の最表面に、多孔質酸化物と貴
金属を含む触媒層を有することも好ましい。これにより
連続再生式ＤＰＦとすることができる。触媒層に用いら
れる多孔質酸化物としては、アルミナ，ジルコニア，セ
リア，チタニアなどの酸化物あるいはこれらの複数種か
らなる複合酸化物などを用いることができる。It is also preferable that the DPF of the present invention has a catalyst layer containing a porous oxide and a noble metal on the outermost surface of the pores of the partition wall which divides the inflow side cell and the outflow side cell. As a result, a continuous regeneration type DPF can be obtained. As the porous oxide used in the catalyst layer, oxides of alumina, zirconia, ceria, titania, etc., or composite oxides composed of a plurality of these can be used.
【００２５】触媒層の形成量は、ハニカム構造体の細孔
径にもよるが、厚さが１〜20μｍの範囲、あるいはハニ
カム構造体の体積１リットルあたり60〜 200ｇの範囲と
することが好ましい。触媒層の形成量がこの範囲より少
なくなると、貴金属が高密度に担持されるため高温に晒
されると貴金属の粒成長が生じて活性が低下する場合が
ある。また触媒層の形成量がこの範囲より多くなると、
細孔の径及び開口面積が低下し圧損が増大してしまう。The formation amount of the catalyst layer depends on the pore diameter of the honeycomb structure, but the thickness is preferably in the range of 1 to 20 μm or in the range of 60 to 200 g per liter of the volume of the honeycomb structure. When the amount of the catalyst layer formed is less than this range, the noble metal is supported at a high density, so that the grain growth of the noble metal may occur and the activity may be reduced when exposed to high temperature. When the amount of the catalyst layer formed exceeds this range,
The diameter of the pores and the opening area decrease, and the pressure loss increases.
【００２６】触媒層を形成するには、多孔質酸化物粉末
をアルミナゾルなどのバインダ成分及び水とともにスラ
リーとし、そのスラリーをセル隔壁に含浸させた後に焼
成し、その後少なくとも貴金属を担持すればよい。スラ
リーをセル隔壁に含浸させるには通常の浸漬法を用いる
ことができるが、エアブローあるいは吸引によって細孔
内に入ったスラリーの余分なものを除去することが望ま
しい。In order to form the catalyst layer, a porous oxide powder may be made into a slurry together with a binder component such as alumina sol and water, and the slurry may be impregnated into the cell partition walls and fired, and then at least a noble metal may be supported. A normal dipping method can be used to impregnate the cell partition wall with the slurry, but it is desirable to remove an excess of the slurry that has entered the pores by air blow or suction.
【００２７】触媒層には少なくとも貴金属が担持されて
いる。この貴金属としては、触媒反応によってＰＭの酸
化を促進するものであれば用いることができるが、Pt、
Rh、Pdなどの白金族の貴金属から選ばれた一種又は複数
種を担持することが特に好ましい。貴金属の担持量は、
ハニカム構造体１リットルあたり 0.5〜10ｇの範囲とす
ることが好ましい。担持量がこれより少ないと活性が低
すぎて実用的でなく、この範囲より多く担持しても活性
が飽和するとともにコストアップとなってしまう。At least a noble metal is supported on the catalyst layer. As the noble metal, any one that promotes the oxidation of PM by a catalytic reaction can be used, but Pt,
It is particularly preferable to carry one or more selected from platinum group precious metals such as Rh and Pd. The amount of precious metal loaded is
It is preferable to set it in the range of 0.5 to 10 g per liter of the honeycomb structure. If the supported amount is less than this, the activity is too low to be practical, and if the supported amount is more than this range, the activity is saturated and the cost increases.
【００２８】また貴金属に加えて、Ba，Ca，Srなどのア
ルカリ土類金属、Na，Ｋ，Li，Csなどのアルカリ金属、
あるいはLa，Nd，Sc，Ｙなどの希土類元素から選ばれる
NOx吸蔵材をさらに担持することが好ましい。NOx 吸蔵
材を担持することでNOx 吸蔵放出能が発現され、NOx 浄
化能が向上する。このNOx 吸蔵材の担持量は、ハニカム
構造体１リットルあたり0.01〜２モルの範囲とすること
が好ましい。担持量がこれより少ないとNOx 吸蔵放出能
が発現されず、これより多く担持するとPtなどの貴金属
を覆って酸化能が低下するようになる。In addition to noble metals, alkaline earth metals such as Ba, Ca and Sr, alkali metals such as Na, K, Li and Cs,
Or selected from rare earth elements such as La, Nd, Sc, Y
It is preferable to further support the NO x storage material. By supporting the NO x storage material, the NO x storage and release ability is expressed, and the NO x purification ability is improved. The amount of the NO x storage material supported is preferably in the range of 0.01 to 2 mol per liter of the honeycomb structure. If the supported amount is less than this, NO x storage and release ability will not be expressed, and if the supported amount is more than this, the noble metal such as Pt will be covered and the oxidizing ability will decrease.
【００２９】貴金属及びNOx 吸蔵材を担持するには、貴
金属又はNOx 吸蔵元素の硝酸塩などを溶解した溶液を用
い、吸着担持法、吸水担持法などによって多孔質酸化物
層に担持すればよい。また多孔質酸化物粉末に予め貴金
属を担持しておき、その触媒粉末を用いて触媒層を形成
した後にNOx 吸蔵材を担持することもできる。In order to support the noble metal and the NO x storage material, a solution in which the noble metal or the nitrate of the NO x storage element is dissolved may be used to support the porous oxide layer by an adsorption supporting method, a water absorption supporting method or the like. . Alternatively, the porous oxide powder may be loaded with a noble metal in advance, and the catalyst powder may be used to form a catalyst layer, and then the NO x storage material may be loaded.
【００３０】[0030]
【実施例】以下、実施例及び比較例により本発明を具体
的に説明する。EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples.
【００３１】（実施例１）図１に本実施例のＤＰＦの拡
大断面図を示す。このＤＰＦは、コーディエライトから
なるＤＰＦ基材１と、ＤＰＦ基材１のセル隔壁10に存在
する細孔11の表面に形成された SiC層２とから構成され
ている。(Embodiment 1) FIG. 1 shows an enlarged sectional view of a DPF of this embodiment. This DPF is composed of a DPF base material 1 made of cordierite, and a SiC layer 2 formed on the surface of pores 11 existing in the cell partition walls 10 of the DPF base material 1.
【００３２】このＤＰＦにおける複数のセルは、排ガス
下流端がコーディエライトからなる目詰め部12をもつ流
入側セル13と、流入側セル13に隣接し排ガス上流端がコ
ーディエライトで目詰めされた流出側セル14と、から構
成されている。またセル隔壁10には、平均細孔径30μｍ
の細孔11が形成され、流入側セル13と流出側セル14とは
細孔11によって互いに連通している。In the plurality of cells in this DPF, an exhaust gas downstream end has an inflow side cell 13 having a plugging portion 12 made of cordierite, and an exhaust gas upstream end adjacent to the inflow side cell 13 is plugged with cordierite. And the outflow-side cell 14, The cell partition wall 10 has an average pore diameter of 30 μm.
The pores 11 are formed, and the inflow side cells 13 and the outflow side cells 14 are communicated with each other through the pores 11.
【００３３】２リットルのコーディエライト製ＤＰＦ基
材１（断面積130cm2・セル密度 300／in2 ）を用意し
た。このＤＰＦ基材１は、図２に示すように SiC層２を
もたないこと以外は図１のＤＰＦ基材１と同様の構造を
有している。A 2 liter cordierite DPF substrate 1 (cross-sectional area 130 cm 2 , cell density 300 / in 2 ) was prepared. This DPF substrate 1 has the same structure as the DPF substrate 1 of FIG. 1 except that it does not have the SiC layer 2 as shown in FIG.
【００３４】このハニカム基材１をテトラエトキシシラ
ンのエタノール溶液と共に、互いに接触しないように圧
力容器内に設置し、真空下 200℃で 0.5時間保持して、
セル隔壁10の細孔11の表面にシラノール基を生成させ
た。次いで一酸化炭素雰囲気下にて 800℃で10時間処理
し、シラノール基を還元するとともに炭化してセル隔壁
10の細孔11の表面に SiC層２を形成した。 SiC層２は
0.5ｇ／Ｌ（平均厚さ0.01μｍ）形成された。This honeycomb substrate 1 was placed together with an ethanol solution of tetraethoxysilane in a pressure vessel so as not to come into contact with each other, and kept under vacuum at 200 ° C. for 0.5 hours,
A silanol group was generated on the surface of the pores 11 of the cell partition wall 10. Then, it is treated in a carbon monoxide atmosphere at 800 ° C for 10 hours to reduce the silanol groups and carbonize the cell partition walls.
The SiC layer 2 was formed on the surface of the 10 pores 11. SiC layer 2
0.5 g / L (average thickness 0.01 μm) was formed.
【００３５】（実施例２）実施例１と同様のＤＰＦ基材
１を用い、真空下 200℃での保持時間を１時間としたこ
と以外は実施例１と同様にしてシラノール基を生成させ
た。そして実施例１と同様にして、セル隔壁10の細孔11
の表面に SiC層２を形成した。 SiC層２は10ｇ／Ｌ（平
均厚さ 0.1μｍ）形成された。Example 2 A silanol group was produced in the same manner as in Example 1 except that the same DPF substrate 1 as in Example 1 was used and the holding time at 200 ° C. under vacuum was 1 hour. . Then, in the same manner as in Example 1, the pores 11 of the cell partition wall 10
A SiC layer 2 was formed on the surface of the. The SiC layer 2 was formed at 10 g / L (average thickness 0.1 μm).
【００３６】（実施例３）実施例１と同様のＤＰＦ基材
１を用い、真空下 200℃での保持時間を２時間としたこ
と以外は実施例１と同様にしてシラノール基を生成させ
た。そして実施例１と同様にして、セル隔壁10の細孔11
の表面に SiC層２を形成した。 SiC層２は50ｇ／Ｌ（平
均厚さ１μｍ）形成された。Example 3 A silanol group was produced in the same manner as in Example 1 except that the same DPF substrate 1 as in Example 1 was used and the holding time at 200 ° C. under vacuum was 2 hours. . Then, in the same manner as in Example 1, the pores 11 of the cell partition wall 10
A SiC layer 2 was formed on the surface of the. The SiC layer 2 was formed at 50 g / L (average thickness 1 μm).
【００３７】（実施例４）実施例１と同様のＤＰＦ基材
１を用い、テトラエトキシシランと共に互いに接触しな
いように圧力容器内に設置した。そこへ CO2ガスを導入
し、 150℃， 30MPaで保持して、 CO2にテトラエトキシ
シランが溶解した超臨界雰囲気を形成した。この状態で
５時間保持し、セル隔壁10の細孔11の表面にシラノール
基を生成させた。冷却後 CO2を抜き、一酸化炭素雰囲気
下にて 800℃で５時間処理し、シラノール基を還元する
とともに炭化してセル隔壁10の細孔11の表面に SiC層２
を形成した。 SiC層２は45ｇ／Ｌ（平均厚さ１μｍ）形
成された。(Example 4) The same DPF substrate 1 as in Example 1 was used and placed in a pressure vessel so as not to come into contact with each other together with tetraethoxysilane. CO 2 gas was introduced there, and it was maintained at 150 ° C and 30 MPa to form a supercritical atmosphere in which tetraethoxysilane was dissolved in CO 2 . This state was maintained for 5 hours to generate silanol groups on the surfaces of the pores 11 of the cell partition wall 10. After cooling, remove CO 2 and treat it in a carbon monoxide atmosphere at 800 ° C for 5 hours to reduce the silanol groups and carbonize them to form the SiC layer 2 on the surface of the pores 11 of the cell partition wall 10.
Was formed. The SiC layer 2 was formed at 45 g / L (average thickness 1 μm).
【００３８】（実施例５）実施例１と同様のＤＰＦ基材
１を用い、テトラエトキシシランのエタノール溶液と共
に真空下 200℃で２時間保持して、セル隔壁10の細孔11
の表面にシラノール基を生成させた。これを乾燥後、10
μｍのカーボン粉末を１ｇ／hrで２時間流通させ、次い
でN2流通下 800℃にて５時間処理してシラノール基を還
元するとともに窒化し、その後大気流通下 700℃で２時
間処理してカーボン粉末を焼却除去した。セル隔壁10の
細孔11の表面に形成された Si3N4層は30ｇ／Ｌ（平均厚
さ 0.8μｍ）である。(Example 5) The same DPF substrate 1 as in Example 1 was used, and the DPF substrate 1 was kept at 200 ° C for 2 hours under vacuum together with an ethanol solution of tetraethoxysilane to obtain pores 11 in the cell partition wall 10.
Silanol groups were generated on the surface of. After drying this, 10
The carbon powder of μm was circulated at 1 g / hr for 2 hours, then treated at 800 ° C for 5 hours under N 2 to reduce silanol groups and nitrided, and then treated at 700 ° C for 2 hours under air to treat carbon. The powder was burned off. The Si 3 N 4 layer formed on the surface of the pores 11 of the cell partition 10 is 30 g / L (average thickness 0.8 μm).
【００３９】（比較例）図２に示した実施例１と同様の
ＤＰＦ基材１を比較例とした。Comparative Example A DPF substrate 1 similar to that of Example 1 shown in FIG. 2 was used as a comparative example.
【００４０】＜試験・評価＞実施例１と比較例のＤＰＦ
を触媒コンバータにそれぞれ配置し、エンジンベンチに
て２Ｌ直噴ディーゼルエンジンの排気系にそれぞれ取り
付けた。そしてそれぞれ 1500rpm×30Nmで運転し、ＤＰ
Ｆの中心部と外周部の温度を連続的に測定した。結果を
図３に示す。<Test / Evaluation> DPFs of Example 1 and Comparative Example
Were placed in the catalytic converters and attached to the exhaust system of the 2L direct injection diesel engine by the engine bench. And each is operated at 1500rpm × 30Nm, DP
The temperature of the central portion and the outer peripheral portion of F was continuously measured. The results are shown in Fig. 3.
【００４１】図３より、中心部の昇温状況に関しては、
実施例１と比較例とに差は認められない。しかし外周部
では、実施例１のＤＰＦは中心部とほとんど同様に速や
かに昇温しているのに対し、比較例のＤＰＦの昇温速度
は小さく最高温度も低いことがわかる。すなわち実施例
１のＤＰＦでは SiC層２を形成したことで熱伝導性が大
きく向上し、中心部の熱が拡散して外周部も速やかに加
熱されたことが明らかである。From FIG. 3, regarding the temperature rising condition of the central portion,
No difference is observed between Example 1 and Comparative Example. However, in the outer peripheral portion, the DPF of Example 1 rapidly increases its temperature almost as in the central portion, whereas it is understood that the temperature increase rate of the DPF of the comparative example is small and the maximum temperature is low. That is, in the DPF of Example 1, it is apparent that the formation of the SiC layer 2 greatly improved the thermal conductivity, the heat in the central portion was diffused, and the outer peripheral portion was rapidly heated.
【００４２】一方、実施例及び比較例のＤＰＦを触媒コ
ンバータにそれぞれ配置し、エンジンベンチにて２Ｌ直
噴ディーゼルエンジンの排気系にそれぞれ取り付けた。
そしてそれぞれ 1500rpm×30Nmで運転し、ＰＭ堆積量が
３，６，９，12，15ｇとなった時点で 3800rpm× 200Nm
で10分間運転して堆積したＰＭを燃焼させた。なおＰＭ
堆積量はコンバータを取り外し、運転前との重量差によ
り測定した。その後触媒コンバータを取り外し、ＤＰＦ
の溶損の有無を目視にて判定した。結果を表１に示す。On the other hand, the DPFs of the examples and the comparative examples were arranged in the catalytic converters and mounted on the exhaust system of the 2L direct injection diesel engine by the engine bench.
Then, each was operated at 1500 rpm × 30 Nm, and when the PM accumulation amount reached 3, 6, 9, 12, 15 g, 3800 rpm × 200 Nm.
It was operated for 10 minutes to burn the deposited PM. PM
The deposition amount was measured by removing the converter and measuring the difference in weight from that before operation. After that, remove the catalytic converter and
The presence or absence of melting loss was visually determined. The results are shown in Table 1.
【００４３】[0043]
【表１】 [Table 1]
【００４４】表１より、各実施例のＤＰＦは比較例のＤ
ＰＦに比べて溶損が抑制されていることがわかり、これ
は SiC層又は Si3N4層を形成した効果であることが明ら
かである。すなわち各実施例のＤＰＦでは、ＰＭ燃焼時
の燃焼熱は SiC層又は Si3N4層を介してＤＰＦ全体に拡
散し、ＤＰＦ全体が均一な温度となって局部的な過熱が
抑制されたと考えられる。このことは、 SiC層の量（厚
さ）が多くなるほど溶損を抑制する効果が大きいことか
らも明らかである。From Table 1, the DPF of each example is D of the comparative example.
It was found that melting loss was suppressed as compared with PF, and it is clear that this is an effect of forming the SiC layer or the Si 3 N 4 layer. That is, in the DPFs of the respective examples, it is considered that the combustion heat at the time of PM combustion diffused through the SiC layer or the Si 3 N 4 layer to the entire DPF, and the temperature of the entire DPF became uniform to suppress local overheating. To be This is clear from the fact that the larger the amount (thickness) of the SiC layer, the greater the effect of suppressing the melt loss.
【００４５】[0045]
【発明の効果】すなわち本発明のハニカム構造体及びＤ
ＰＦによれば、軽量で熱伝導性に優れ、溶損やクラック
の発生を効果的に抑制することができる。That is, the honeycomb structure of the present invention and D
According to PF, it is lightweight and has excellent thermal conductivity, and it is possible to effectively suppress the occurrence of melting loss and cracks.
【図１】本発明の一実施例のＤＰＦの要部拡大断面図で
ある。FIG. 1 is an enlarged cross-sectional view of a main part of a DPF according to an embodiment of the present invention.
【図２】本発明の一実施例のＤＰＦに用いたＤＰＦ基材
の要部拡大断面図である。FIG. 2 is an enlarged cross-sectional view of a main part of a DPF base material used for the DPF according to the embodiment of the present invention.
【図３】実施例１と比較例のＤＰＦの昇温状況を示すグ
ラフである。FIG. 3 is a graph showing a temperature rise state of DPFs of Example 1 and a comparative example.
１：ＤＰＦ基材 ２： SiC層（熱伝導層） 1
0：セル隔壁
11：細孔 12：目詰め部 1
3：流入側セル
14：流出側セル1: DPF substrate 2: SiC layer (heat conduction layer) 1
0: Cell partition wall 11: Pore 12: Clogging part 1
3: Inflow side cell 14: Outflow side cell
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｂ０１Ｊ 27/24 Ｂ０１Ｊ 35/04 ３０１Ｅ ４Ｇ０６９ 35/04 ３０１ Ｃ０４Ｂ 41/85 Ｂ Ｃ０４Ｂ 41/85 ＺＡＢＤ ＺＡＢ 41/87 Ｄ 41/87 Ｆ０１Ｎ 3/02 ３２１Ａ Ｆ０１Ｎ 3/02 ３２１ 3/10 Ａ 3/10 3/24 Ｅ 3/24 3/28 ３０１Ｐ 3/28 ３０１ Ｂ０１Ｄ 53/36 １０４Ｂ Ｆターム(参考） 3G090 AA02 AA03 CA04 3G091 AA02 AA18 AB02 AB06 AB13 BA08 BA39 GA06 GA07 GA17 GB03W GB04W GB05W GB10X GB17W GB17X GB19X 4D019 AA01 BA05 BB06 BC07 BC12 CA01 4D048 AA14 AB01 BA03X BA06X BA10X BA30X BA31X BA33X BA41X BA45X BA46X BB02 BB14 4G019 FA12 GA02 4G069 AA03 AA08 BA01A BA01B BA04A BA05A BA13A BA13B BB02A BB02B BB04A BB11A BB11B BB15A BB15B BC43A BC71A BC71B BC72A BC72B BC75A BC75B BD05A BD05B BE32C CA02 CA03 CA07 CA18 EA19 EB15Y FA01 FA03 FB33 FB34 FB44 FB80 FC02 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) B01J 27/24 B01J 35/04 301E 4G069 35/04 301 C04B 41/85 B C04B 41/85 ZABD ZAB 41 / 87 D 41/87 F01N 3/02 321A F01N 3/02 321 3/10 A 3/10 3/24 E 3/24 3/28 301P 3/28 301 B01D 53/36 104B F term (reference) 3G090 AA02 AA03 CA04 3G091 AA02 AA18 AB02 AB06 AB13 BA08 BA39 GA06 GA07 GA17 GB03W GB04W GB05W GB10X GB17W GB17X GB19X 4D019 AA01 BA05 BB06 BC07 BC12 CA01 4D048 AA14 AB01 BA05A01 BA03XBA31X4531B45XBA31X BA31X BA33X BA41X BA33X BA31X BA31X BA31X BA33X BA13A BA13B BB02A BB02B BB04A BB11A BB11B BB15A BB15B BC43A BC71A BC71B BC72A BC72B BC75A BC75B BD05A BD05B BE32C CA02 CA03 CA07 CA18 EA19 EB15Y FA01 FA03 FB33 FB34 FB44 FB80 FC02
Claims (7)
ルの隔壁に気体が流通可能な細孔をもつハニカム構造体
であって、少なくとも一部の該細孔の表面には炭化ケイ
素又は窒化ケイ素から選ばれる少なくとも一種からなる
熱伝導層をもつことを特徴とするハニカム構造体。1. A honeycomb structure having a plurality of cells made of an oxide and having pores through which gas can flow in partition walls of the cells, wherein at least a part of the pores has a surface of silicon carbide. Alternatively, a honeycomb structure having a heat conductive layer made of at least one selected from silicon nitride.
求項１に記載のハニカム構造体。2. The honeycomb structure according to claim 1, wherein the oxide is cordierite.
構造体からなり、複数のセルは、排ガス下流端が目詰め
された流入側セルと、該流入側セルに隣接し排ガス上流
端が目詰めされた流出側セルと、からなることを特徴と
するディーゼルパティキュレートフィルタ。3. The honeycomb structure according to claim 1 or 2, wherein the plurality of cells have an inflow side cell in which an exhaust gas downstream end is clogged, and an exhaust gas upstream end adjacent to the inflow side cell. A diesel particulate filter, which is composed of a clogged outlet cell.
する隔壁の細孔の最表面には、多孔質酸化物と貴金属を
含む触媒層をもつ請求項３に記載のディーゼルパティキ
ュレートフィルタ。4. The diesel particulate filter according to claim 3, wherein a catalyst layer containing a porous oxide and a noble metal is provided on the outermost surface of the pores of the partition walls that partition the inflow side cell and the outflow side cell.
ルの隔壁に気体が流通可能な細孔をもつハニカム基材の
少なくとも一部の該細孔の表面にシラノール基を形成す
るシラノール処理を行い、次いで少なくとも炭素を含む
還元雰囲気中で熱処理することを特徴とするハニカム構
造体の製造方法。5. A silanol forming a silanol group on the surface of at least a part of a honeycomb substrate having a plurality of cells made of an oxide and having pores through which gas can flow in partition walls of the cells. A method for manufacturing a honeycomb structure, comprising performing a treatment and then performing a heat treatment in a reducing atmosphere containing at least carbon.
ルの隔壁に気体が流通可能な細孔をもつハニカム基材の
少なくとも一部の該細孔の表面にシラノール基を形成す
るシラノール処理を行い、次いで窒化処理することを特
徴とするハニカム構造体の製造方法。6. A silanol forming a silanol group on the surface of at least a part of a honeycomb substrate having a plurality of cells made of an oxide and having pores through which gas can flow in partition walls of the cells. A method for manufacturing a honeycomb structure, comprising performing a treatment and then a nitriding treatment.
らなる請求項５又は請求項６に記載のハニカム構造体の
製造方法。7. The method for manufacturing a honeycomb structure according to claim 5, wherein the honeycomb substrate is made of cordierite.
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|---|---|---|---|
| JP2002126099A JP3899998B2 (en) | 2002-04-26 | 2002-04-26 | Honeycomb structure, manufacturing method thereof, and diesel particulate filter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002126099A JP3899998B2 (en) | 2002-04-26 | 2002-04-26 | Honeycomb structure, manufacturing method thereof, and diesel particulate filter |
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| Publication Number | Publication Date |
|---|---|
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| JP3899998B2 JP3899998B2 (en) | 2007-03-28 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7605110B2 (en) | 2006-04-05 | 2009-10-20 | Denso Corporation | Ceramic body, ceramic catalyst body and related manufacturing methods |
| US7838462B2 (en) | 2005-01-28 | 2010-11-23 | Denso Corporation | Ceramic support capable of supporting catalyst, catalyst-ceramic body and processes for producing same |
| JP2011189241A (en) * | 2010-03-12 | 2011-09-29 | Ngk Insulators Ltd | Honeycomb filter |
| CN109529828A (en) * | 2018-12-17 | 2019-03-29 | 南通斐腾新材料科技有限公司 | A kind of high thermal conductivity VOCs catalyst |
| CN114931962A (en) * | 2022-06-20 | 2022-08-23 | 无锡威孚环保催化剂有限公司 | Quick ignition catalyst coating and preparation method thereof |
-
2002
- 2002-04-26 JP JP2002126099A patent/JP3899998B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7838462B2 (en) | 2005-01-28 | 2010-11-23 | Denso Corporation | Ceramic support capable of supporting catalyst, catalyst-ceramic body and processes for producing same |
| US7605110B2 (en) | 2006-04-05 | 2009-10-20 | Denso Corporation | Ceramic body, ceramic catalyst body and related manufacturing methods |
| JP2011189241A (en) * | 2010-03-12 | 2011-09-29 | Ngk Insulators Ltd | Honeycomb filter |
| CN109529828A (en) * | 2018-12-17 | 2019-03-29 | 南通斐腾新材料科技有限公司 | A kind of high thermal conductivity VOCs catalyst |
| CN114931962A (en) * | 2022-06-20 | 2022-08-23 | 无锡威孚环保催化剂有限公司 | Quick ignition catalyst coating and preparation method thereof |
| CN114931962B (en) * | 2022-06-20 | 2023-07-18 | 无锡威孚环保催化剂有限公司 | Quick ignition catalyst coating and preparation method thereof |
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| Publication number | Publication date |
|---|---|
| JP3899998B2 (en) | 2007-03-28 |
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