JP2014064997A - Honeycomb structure, and exhaust gas purifying catalyst - Google Patents

Honeycomb structure, and exhaust gas purifying catalyst Download PDF

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JP2014064997A
JP2014064997A JP2012212292A JP2012212292A JP2014064997A JP 2014064997 A JP2014064997 A JP 2014064997A JP 2012212292 A JP2012212292 A JP 2012212292A JP 2012212292 A JP2012212292 A JP 2012212292A JP 2014064997 A JP2014064997 A JP 2014064997A
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honeycomb structure
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exhaust gas
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JP5932589B2 (en
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Takaya Yamaguchi
喬也 山口
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NGK Insulators Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a honeycomb structure that can be fully satisfactorily compatible with a high level as a catalyst carrier of an exhaust gas purifying catalyst concerning a temperature rising property, a heat retaining property and strength, and to provide an exhaust gas purifying catalyst using the same.SOLUTION: A honeycomb structure 10 is used as a catalyst carrier of an exhaust gas purifying catalyst, in which a shape of a cell 13 in a cross section perpendicular to an extending direction of the cell 13 is an enneagon. The enneagon is shaped to have three vertices existing in every other one in a circumferential direction of a regular hexagon among six vertices of the regular hexagon, and six new vertices formed by cutting corners including three remaining vertices with a line segment presenting on the side in parallel to each diagonal for connecting three vertices and forming three remaining vertices by both ends, respectively. Multiple cells 13 are disposed such that the sides for connecting the new vertices and the vertex other than the new vertices with each other are opposed in a parallel state between adjacent cells 13, 13.

Description

本発明は、排ガス浄化用触媒の触媒担体として使用されるハニカム構造体と、それを用いた排ガス浄化用触媒とに関する。   The present invention relates to a honeycomb structure used as a catalyst carrier of an exhaust gas purification catalyst and an exhaust gas purification catalyst using the honeycomb structure.

自動車等の排ガスを浄化するために使用される排ガス浄化用触媒として、セラミック材料等からなるハニカム構造体に、触媒成分を担持させたものが使用されている。触媒成分を担持させるための触媒担体となるハニカム構造体は、流体(排ガス)の入口側となる入口端面から流体の出口側となる出口端面まで延びる複数のセルを区画形成する多孔質の隔壁を有するものであり、この隔壁上に触媒成分を含む触媒層が担持される。   As an exhaust gas purifying catalyst used for purifying exhaust gas from automobiles or the like, a honeycomb structure made of a ceramic material or the like and carrying a catalyst component is used. A honeycomb structure serving as a catalyst carrier for supporting a catalyst component has a porous partition wall that partitions and forms a plurality of cells extending from an inlet end surface serving as a fluid (exhaust gas) inlet side to an outlet end surface serving as a fluid outlet side. The catalyst layer containing the catalyst component is supported on the partition wall.

従来、排ガス浄化用触媒の触媒担体として用いられるハニカム構造体には、セルの長さ方向に垂直な断面におけるセルの形状(以下、単に「セル形状」と称する場合がある。)が六角形のものが広く用いられている(例えば、特許文献1参照)。また、最近では、セル形状が十二角形のハニカム構造体が使用される場合もある(例えば、特許文献2参照)。   Conventionally, a honeycomb structure used as a catalyst carrier for an exhaust gas purifying catalyst has a hexagonal cell shape (hereinafter sometimes simply referred to as “cell shape”) in a cross section perpendicular to the cell length direction. The thing is widely used (for example, refer patent document 1). Recently, a honeycomb structure having a dodecagonal cell shape is sometimes used (see, for example, Patent Document 2).

特開2011−167632号公報JP 2011-167632 A 特開2009−95827号公報JP 2009-95827 A

排ガス浄化用触媒の触媒担体として用いられるハニカム構造体に重要な特性として、昇温性、保温性及び強度が挙げられる。昇温性は、ハニカム構造体に担持された触媒成分を、迅速にその活性温度まで昇温させる、即ち、排ガス浄化用触媒のライトオフ性を高めるという観点から重要な特性である。また、保温性は、ハニカム構造体に担持された触媒成分が活性温度まで昇温した後、その活性温度を維持するという観点から重要な特性である。また、通常、排ガス浄化用触媒は、筒状の缶体内に収納(キャニング)した状態で、自動車等の排気系に搭載されるが、この収納の際にハニカム構造体の外周面にかかる圧力により、ハニカム構造体が損傷することを防ぐため、強度も重要な特性である。   Important characteristics of the honeycomb structure used as the catalyst carrier of the exhaust gas purifying catalyst include temperature rise property, heat retention property and strength. The temperature rise property is an important characteristic from the viewpoint of rapidly raising the catalyst component supported on the honeycomb structure to its activation temperature, that is, improving the light-off property of the exhaust gas purification catalyst. Further, the heat retention is an important characteristic from the viewpoint of maintaining the activation temperature after the catalyst component supported on the honeycomb structure has been heated to the activation temperature. Further, the exhaust gas purifying catalyst is usually mounted in an exhaust system of an automobile or the like in a state where it is stored (canned) in a cylindrical can body, but due to the pressure applied to the outer peripheral surface of the honeycomb structure during the storage Strength is also an important characteristic to prevent the honeycomb structure from being damaged.

そこで、セル形状が六角形のハニカム構造体と、セル形状が十二角形のハニカム構造体とについて、昇温性、保温性及び強度を比較検討する。図7は、セル形状が六角形のハニカム構造体の、セルの延びる方向に垂直な断面の一部を示す部分断面図であり、図8は、セル形状が十二角形のハニカム構造体の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。これらの図を比較してわかるように、セル形状が十二角形のハニカム構造体40の隔壁44の交点部46は、セル形状が六角形のハニカム構造体30の隔壁34の交点部36よりも大きい。このため、材質、体積(セル部分も含む全体積)、セル密度、隔壁の厚さ等が同等である場合、セル形状が六角形のハニカム構造体は、セル形状が十二角形のハニカム構造体よりも、質量及び熱容量が小さくなる。   In view of this, the honeycomb structure having a hexagonal cell shape and the honeycomb structure having a dodecagonal cell shape are compared and examined for temperature rise, heat retention and strength. FIG. 7 is a partial cross-sectional view showing a part of a cross section perpendicular to the cell extending direction of a honeycomb structure having a hexagonal cell shape, and FIG. 8 is a diagram of a honeycomb structure having a dodecagonal cell shape. It is a fragmentary sectional view which shows a part of cross section perpendicular | vertical to the cell extending direction. As can be seen by comparing these figures, the intersection 46 of the partition 44 of the honeycomb structure 40 having a dodecagonal cell shape is more than the intersection 36 of the partition 34 of the honeycomb structure 30 having a hexagonal cell shape. large. Therefore, when the material, volume (total volume including the cell portion), cell density, partition wall thickness, etc. are the same, the honeycomb structure having a hexagonal cell shape is a honeycomb structure having a dodecagonal cell shape. Rather, the mass and heat capacity are smaller.

そして、ハニカム構造体の昇温性は、熱容量が小さいほど高くなるため、セル形状が六角形のハニカム構造体は、セル形状が十二角形のハニカム構造体よりも高い昇温性を有する。一方、ハニカム構造体の保温性は、熱容量が大きいほど高くなるため、セル形状が十二角形のハニカム構造体は、セル形状が六角形のハニカム構造体よりも高い保温性を有する。また、ハニカム構造体の強度は、隔壁の交点部が大きい(厚肉である)ほど高くなるため、セル形状が十二角形のハニカム構造体は、セル形状が六角形のハニカム構造体よりも高い強度を有する。   And since the temperature rise property of a honeycomb structure becomes so high that a heat capacity is small, the honeycomb structure whose cell shape is a hexagon has higher temperature rise property than the honeycomb structure whose cell shape is a dodecagon. On the other hand, since the heat retention of the honeycomb structure increases as the heat capacity increases, the honeycomb structure having a dodecagonal cell shape has higher heat retention than the honeycomb structure having a hexagonal cell shape. In addition, since the strength of the honeycomb structure increases as the intersection of the partition walls increases (thickness), the honeycomb structure having a dodecagonal cell shape is higher than the honeycomb structure having a hexagonal cell shape. Has strength.

このように、セル形状が六角形のハニカム構造体と、セル形状が十二角形のハニカム構造体とには、それぞれ一長一短があり、昇温性と保温性及び強度とは、トレードオフの関係にある。よって、従来のセル形状が六角形のハニカム構造体やセル形状が十二角形のハニカム構造体では、昇温性と保温性及び強度との両方を、排ガス浄化用触媒の触媒担体として十分満足できるレベルまで高めることは困難であった。   Thus, the honeycomb structure having a hexagonal cell shape and the honeycomb structure having a dodecagonal cell shape each have advantages and disadvantages, and there is a trade-off relationship between temperature rise, heat retention, and strength. is there. Therefore, the conventional honeycomb structure having a hexagonal cell shape and the honeycomb structure having a dodecagonal cell shape can sufficiently satisfy both the temperature rise performance, the heat retention property, and the strength as the catalyst carrier of the exhaust gas purification catalyst. It was difficult to increase to the level.

本発明は、このような問題に鑑みてなされたものであり、昇温性と保温性及び強度とを、排ガス浄化用触媒の触媒担体として十分満足できるような高いレベルで両立可能なハニカム構造体と、それを用いた排ガス浄化用触媒とを提供することを目的とする。   The present invention has been made in view of such problems, and has a honeycomb structure capable of satisfying both a high temperature level, a high temperature retention characteristic, and a high strength as a catalyst carrier for an exhaust gas purification catalyst. And an exhaust gas purifying catalyst using the same.

上記目的を達成するため、本発明によれば、以下のハニカム構造体及び排ガス浄化用触媒が提供される。   In order to achieve the above object, according to the present invention, the following honeycomb structure and exhaust gas purifying catalyst are provided.

[1] 流体の入口側となる入口端面から流体の出口側となる出口端面まで延びる複数のセルを区画形成する多孔質の隔壁を有し、前記セルの延びる方向に垂直な断面における前記セルの形状が九角形であり、前記九角形が、正六角形の6つの頂点の内、当該正六角形の周方向において1つ置きに存在する3つの頂点と、「当該3つの頂点を結ぶそれぞれの対角線と平行で、両端が残りの3つの頂点をそれぞれ形成する辺上に在る線分」によって、前記残りの3つの頂点を含む角部が切断されることにより形成された6つの新たな頂点とを有する形状であり、隣接するセル間において、前記新たな頂点と前記新たな頂点以外の頂点とを結ぶ辺同士が平行な状態で対向するように、前記複数のセルが配置されており、排ガス浄化用触媒の触媒担体として用いられるハニカム構造体。 [1] A porous partition wall defining a plurality of cells extending from an inlet end surface serving as a fluid inlet side to an outlet end surface serving as a fluid outlet side, and having a cross section perpendicular to the cell extending direction. The shape is a hexagon, and among the six vertices of the regular hexagon, the octagon has three vertices that exist every other in the circumferential direction of the regular hexagon, and “the respective diagonal lines connecting the three vertices; 6 new vertices formed by cutting off the corners including the remaining three vertices by "parallel line segments on both sides that respectively form the remaining three vertices" The plurality of cells are arranged so that the sides connecting the new vertex and the vertex other than the new vertex face each other in parallel between adjacent cells, and the exhaust gas purification Catalyst carrier Honeycomb structure used as.

[2] 前記線分が、前記残りの3つの頂点から前記線分までの距離をaとし、前記残りの3つの頂点から前記対角線までの距離をpとしたときに、下式(1)の関係を満たすものである[1]に記載のハニカム構造体。
0.2p≦a≦0.7p ・・・(1)
[2] When the distance from the remaining three vertices to the line segment is a and the distance from the remaining three vertices to the diagonal line is p, the line segment has the following formula (1) The honeycomb structure according to [1], which satisfies the relationship.
0.2p ≦ a ≦ 0.7p (1)

[3] 前記隔壁の厚さが、38〜305μmである[1]又は[2]に記載のハニカム構造体。 [3] The honeycomb structure according to [1] or [2], wherein the partition wall has a thickness of 38 to 305 μm.

[4] [1]〜[3]の何れかに記載のハニカム構造体の前記隔壁上に、排ガス中の有害物質の浄化を促進する触媒成分を含有する触媒層が担持されてなる排ガス浄化用触媒。 [4] For exhaust gas purification, wherein a catalyst layer containing a catalyst component that promotes purification of harmful substances in exhaust gas is supported on the partition walls of the honeycomb structure according to any one of [1] to [3]. catalyst.

本発明のハニカム構造体は、高い昇温性と高い保温性及び強度とを両立することができる。また、本発明の排ガス浄化用触媒は、このようなハニカム構造体を触媒担体として用いているため、高いライトオフ性を発揮するとともに、触媒活性温度の維持が容易であり、また、キャニング時の損傷も生じ難い。   The honeycomb structure of the present invention can achieve both a high temperature rising property and a high heat retaining property and strength. Further, since the exhaust gas purifying catalyst of the present invention uses such a honeycomb structure as a catalyst carrier, it exhibits a high light-off property and can easily maintain the catalyst activation temperature. Damage is unlikely to occur.

本発明のハニカム構造体の一の実施形態の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。1 is a partial cross-sectional view showing a part of a cross section perpendicular to a cell extending direction of an embodiment of a honeycomb structure of the present invention. 本発明のハニカム構造体の一の実施形態の、セルの延びる方向に平行な断面を示す断面図である。Fig. 3 is a cross-sectional view showing a cross section parallel to the cell extending direction of one embodiment of the honeycomb structure of the present invention. 本発明のハニカム構造体のセル形状を説明するための模式図である。It is a schematic diagram for demonstrating the cell shape of the honeycomb structure of this invention. 本発明の排ガス浄化用触媒の一の実施形態の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。It is a fragmentary sectional view which shows a part of cross section perpendicular | vertical to the cell extending direction of one Embodiment of the catalyst for exhaust gas purification of this invention. 本発明の排ガス浄化用触媒の一の実施形態の、セルの延びる方向に平行な断面を示す断面図である。It is sectional drawing which shows the cross section parallel to the cell extending direction of one Embodiment of the exhaust gas purification catalyst of this invention. 実施例における昇温性及び保温性の評価方法を説明するためのグラフである。It is a graph for demonstrating the evaluation method of the temperature rising property and heat retention in an Example. 従来のセル形状が六角形のハニカム構造体の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。FIG. 6 is a partial cross-sectional view showing a part of a cross section perpendicular to a cell extending direction of a conventional honeycomb structure having a hexagonal cell shape. 従来のセル形状が十二角形のハニカム構造体の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。FIG. 6 is a partial cross-sectional view showing a part of a cross section perpendicular to a cell extending direction of a conventional honeycomb structure having a dodecagonal cell shape.

以下、本発明の実施の形態について具体的に説明するが、本発明は以下の実施の形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、当業者の通常の知識に基づいて、以下の実施の形態に対し適宜変更、改良等が加えられたものも本発明の範囲に入ることが理解されるべきである。   Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and is based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. In addition, it should be understood that modifications, improvements, and the like appropriately added to the following embodiments also fall within the scope of the present invention.

(1)ハニカム構造体:
図1は、本発明のハニカム構造体の一の実施形態の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。図2は、本発明のハニカム構造体の一の実施形態の、セルの延びる方向に平行な断面を示す断面図である。図3は、本発明のハニカム構造体のセル形状を説明するための模式図である。
(1) Honeycomb structure:
FIG. 1 is a partial cross-sectional view showing a part of a cross section perpendicular to the cell extending direction of one embodiment of the honeycomb structure of the present invention. FIG. 2 is a cross-sectional view showing a cross section parallel to the cell extending direction of one embodiment of the honeycomb structure of the present invention. FIG. 3 is a schematic diagram for explaining the cell shape of the honeycomb structure of the present invention.

本発明のハニカム構造体10は、排ガス浄化用触媒の触媒担体として用いられるものであり、図2に示すように、流体(排ガス)の入口側となる入口端面11から流体の出口側となる出口端面12まで延びる複数のセル13を区画形成する多孔質の隔壁14を有する。   The honeycomb structure 10 of the present invention is used as a catalyst carrier of an exhaust gas purifying catalyst. As shown in FIG. 2, the honeycomb structure 10 is an outlet that is an inlet end surface 11 that is an inlet side of a fluid (exhaust gas) and an outlet that is an outlet side of the fluid. It has a porous partition wall 14 that defines a plurality of cells 13 extending to the end face 12.

本発明のハニカム構造体10は、セル形状が特定の九角形であることを、その主要な特徴とする。この九角形の具体的な形状は、次のようにして特定される。まず、図3に示すように、正六角形の6つの頂点の内、その正六角形の周方向において1つ置きに存在する3つの頂点1(1A,1B,1C)を結ぶ対角線4(4A,4B,4C)を引く。そして、それぞれの対角線4と平行で、その両端が残りの3つの頂点2(2A,2B,2C)をそれぞれ形成する辺上に在る線分5(5A,5B,5C)によって、残りの3つの頂点2をそれぞれ含む角部6(6A,6B,6C)を切断する。ここで、「角部」とは、残りの3つの頂点2及び残りの3つの頂点2をそれぞれ形成する辺の一部(図3の点線部分)である。   The main feature of the honeycomb structure 10 of the present invention is that the cell shape is a specific hexagon. The specific shape of this hexagon is specified as follows. First, as shown in FIG. 3, among the six vertices of a regular hexagon, a diagonal line 4 (4A, 4B) connecting three vertices 1 (1A, 1B, 1C) that exist every other in the circumferential direction of the regular hexagon. , 4C). Then, the remaining 3 by the line segment 5 (5A, 5B, 5C) which is parallel to each diagonal line 4 and whose both ends are on the sides forming the remaining three vertices 2 (2A, 2B, 2C), respectively. The corners 6 (6A, 6B, 6C) each including the two apexes 2 are cut. Here, the “corner part” is a part of the side forming the remaining three vertices 2 and the remaining three vertices 2 (dotted line part in FIG. 3).

こうして角部6を切断することにより、6つの新たな頂点3(3A,3B,3C,3D,3E,3F)が形成される。その結果、前記3つの頂点1(1A,1B,1C)と、前記6つの新たな頂点3(3A,3B,3C,3D,3E,3F)とを有する形状の九角形である、本発明のハニカム構造体10のセル形状が得られる。尚、新たな頂点3は、角部6の切断後における、残りの3つの頂点2をそれぞれ形成していた辺の一部(角部6の切断後に残った部分)と、線分5によって形成される。即ち、前記のようにして得られる九角形の9本の辺の内、3本の辺は、線分5である。   By cutting the corner portion 6 in this way, six new vertices 3 (3A, 3B, 3C, 3D, 3E, 3F) are formed. As a result, the present invention is a hexagonal shape having the three vertices 1 (1A, 1B, 1C) and the six new vertices 3 (3A, 3B, 3C, 3D, 3E, 3F). The cell shape of the honeycomb structure 10 is obtained. The new vertex 3 is formed by a part of the side that formed the remaining three vertices 2 after cutting the corner portion 6 (the portion remaining after cutting the corner portion 6) and the line segment 5. Is done. That is, three of the nine sides of the nine-sided polygon obtained as described above are the line segment 5.

本発明のハニカム構造体10においては、図1に示すように、隣接するセル13,13間において、前記のような九角形の新たな頂点3と新たな頂点以外の頂点1とを結ぶ辺同士が平行な状態で対向するように、複数のセル13が配置されている。尚、この対向する辺と辺との間の部分が、ハニカム構造体10の隔壁14となる。前記のような九角形のセル形状を有する複数のセル13が、このように配置されることより、図1の矢印方向において、2種類の大きさの異なる隔壁の交点部16,17が交互に形成された状態となる。即ち、本発明のハニカム構造体は、従来のセル形状が六角形のハニカム構造体の隔壁の交点部と同等の小さな隔壁の交点部16と、従来のセル形状が十二角形のハニカム構造体の隔壁の交点部と同等の大きな隔壁の交点部17とを併せ持つ。   In the honeycomb structure 10 of the present invention, as shown in FIG. 1, between the adjacent cells 13, 13, sides connecting the new vertex 3 of the nine-sided shape as described above and the vertex 1 other than the new vertex. A plurality of cells 13 are arranged so as to face each other in parallel. Note that the portion between the opposing sides becomes the partition wall 14 of the honeycomb structure 10. By arranging the plurality of cells 13 having the above-mentioned hexagonal cell shape in this way, in the direction of the arrow in FIG. It will be in the formed state. That is, the honeycomb structure of the present invention has a small partition wall intersection 16 equivalent to the partition wall intersection of the conventional hexagonal honeycomb structure, and the conventional cell structure of the dodecagonal honeycomb structure. It also has a large partition intersection 17 that is equivalent to the partition intersection.

このため、材質、体積(セル部分も含む全体積)、セル密度、隔壁の厚さ等が同等である場合、本発明のハニカム構造体10は、小さな隔壁の交点部しか持たない、セル形状が六角形のハニカム構造体よりも、高い保温性及び強度を発現する。また、本発明のハニカム構造体は、大きな隔壁の交点部しか持たない、セル形状が十二角形のハニカム構造体よりも、高い昇温性を発現する。尚、本発明のハニカム構造体10の保温性及び強度は、セル形状が十二角形のハニカム構造体の保温性及び強度と比べても、殆ど遜色がなく、ほぼ同等の保温性及び強度を有する。また、本発明のハニカム構造体の昇温性は、セル形状が六角形のハニカム構造体の昇温性と比べても、殆ど遜色がなく、ほぼ同等の昇温性を有する。   Therefore, when the material, volume (total volume including the cell portion), cell density, partition wall thickness, and the like are the same, the honeycomb structure 10 of the present invention has only intersections of small partition walls and has a cell shape. It exhibits higher heat retention and strength than a hexagonal honeycomb structure. In addition, the honeycomb structure of the present invention exhibits a higher temperature rise than a honeycomb structure having only a large partition wall intersection and having a dodecagonal cell shape. Note that the heat retention and strength of the honeycomb structure 10 of the present invention are almost the same as those of the honeycomb structure having a dodecagonal cell shape, and have substantially the same heat retention and strength. . Further, the temperature rise performance of the honeycomb structure of the present invention is almost the same as that of the honeycomb structure having a hexagonal cell shape, and has almost the same temperature rise performance.

本発明のハニカム構造体10においては、前述のセル形状の特定の際の線分5が、所定の条件を満たすものであることが好ましい。この所定の条件とは、図3に示すように、残りの3つの頂点2から線分5までの距離をaとし、残りの3つの頂点2から対角線4までの距離をpとしたときに、下式(1)の関係を満たすような条件である。
0.2p≦a≦0.7p ・・・(1)
In the honeycomb structure 10 of the present invention, it is preferable that the line segment 5 when the above-described cell shape is specified satisfies a predetermined condition. As shown in FIG. 3, when the distance from the remaining three vertices 2 to the line segment 5 is a and the distance from the remaining three vertices 2 to the diagonal line 4 is p, as shown in FIG. The conditions satisfy the relationship of the following formula (1).
0.2p ≦ a ≦ 0.7p (1)

このような条件を満たす線分5で、角部6が切断されることにより得られる九角形を、本発明のハニカム構造体10のセル形状とすると、ハニカム構造体10の昇温性と保温性及び強度とを、バランス良く、高いレベルで両立することができる。尚、aが0.2pより小さいと、セル形状が六角形のハニカム構造体に対する、保温性及び強度の優位性が十分に発揮されない場合がある。また、aが0.7pより大きいと、セル形状が十二角形のハニカム構造体に対する、昇温性の優位性が十分に発揮されない場合がある。   When the nine-sided shape obtained by cutting the corner portion 6 at the line segment 5 satisfying such a condition is the cell shape of the honeycomb structure 10 of the present invention, the temperature rise and heat retention of the honeycomb structure 10 are as follows. And strength can be balanced at a high level in a balanced manner. If a is smaller than 0.2p, the superiority of heat retention and strength over the honeycomb structure having a hexagonal cell shape may not be sufficiently exhibited. On the other hand, if a is greater than 0.7p, the temperature rise advantage over the honeycomb structure having a dodecagonal cell shape may not be sufficiently exhibited.

本発明において、ハニカム構造体10の隔壁14の厚さは、38〜305μmであることが好ましく、51〜254μmであることが更に好ましい。隔壁14の厚さをこのような範囲にすることにより、昇温性と保温性及び強度とを、バランス良く両立することが容易となる。また、隔壁14に触媒層を担持した際の圧力損失の過剰な上昇を抑制できる。隔壁14の厚さが38μmより薄いと、ハニカム構造体10の保温性及び強度が不十分となることがある。また、隔壁14の厚さが305μmより厚いと、ハニカム構造体10の昇温性が不十分となったり、隔壁14に触媒層を担持した際に、圧力損失が大きくなり過ぎたりすることがある。   In the present invention, the thickness of the partition wall 14 of the honeycomb structure 10 is preferably 38 to 305 μm, and more preferably 51 to 254 μm. By making the thickness of the partition wall 14 in such a range, it becomes easy to achieve a balance between the temperature increase property, the heat retention property and the strength. Further, an excessive increase in pressure loss when the catalyst layer is supported on the partition wall 14 can be suppressed. If the partition wall 14 is thinner than 38 μm, the heat retention and strength of the honeycomb structure 10 may be insufficient. Moreover, if the partition wall 14 is thicker than 305 μm, the temperature rise of the honeycomb structure 10 may be insufficient, or the pressure loss may be excessive when the catalyst layer is supported on the partition wall 14. .

ハニカム構造体10のセル密度は、15〜186セル/cmであることが好ましく、31〜155セル/cmであることが更に好ましい。セル密度をこのような範囲にすることにより、隔壁14に触媒層を担持した際の圧力損失の過剰な上昇を抑えつつ、高い触媒浄化性能を発揮させることができる。セル密度が15セル/cmより低いと、触媒層の担持面積が小さくなり過ぎることがある。また、セル密度が186セル/cmより高いと、ハニカム構造体10の隔壁14に触媒層を担持した際に、圧力損失が大きくなり過ぎることがある。 Cell density of the honeycomb structure 10 is preferably from 15 to 186 cells / cm 2, more preferably from 31 to 155 cells / cm 2. By setting the cell density in such a range, high catalyst purification performance can be exhibited while suppressing an excessive increase in pressure loss when the catalyst layer is supported on the partition wall 14. When the cell density is lower than 15 cells / cm 2 , the supported area of the catalyst layer may become too small. On the other hand, if the cell density is higher than 186 cells / cm 2 , the pressure loss may become too large when the catalyst layer is supported on the partition walls 14 of the honeycomb structure 10.

ハニカム構造体10の開口率は、70〜95%であることが好ましく、78〜92%であることが更に好ましい。開口率が70%より低いと、ハニカム構造体10の圧力損失が大きくなり過ぎることがある。また、開口率が95%より高いと、ハニカム構造体10の保温性及び強度が不十分となることがある。尚、ここで言う「開口率」とは、ハニカム構造体の長さ方向に垂直な断面の全面積(セルの断面積も含めた面積)に対するセルの断面積の割合を意味する。   The aperture ratio of the honeycomb structure 10 is preferably 70 to 95%, and more preferably 78 to 92%. If the aperture ratio is lower than 70%, the pressure loss of the honeycomb structure 10 may become too large. Further, if the aperture ratio is higher than 95%, the heat retention and strength of the honeycomb structure 10 may be insufficient. The “aperture ratio” here refers to the ratio of the cell cross-sectional area to the total area of the cross section perpendicular to the longitudinal direction of the honeycomb structure (the area including the cell cross-sectional area).

ハニカム構造体10の形状は特に限定されず、例えば、底面が円形の筒状(円筒形状)、底面がオーバル形状の筒状、底面が多角形(四角形、五角形、六角形、七角形、八角形等)の筒状等の形状とすることができる。また、ハニカム構造体10の大きさも特に限定されず、排ガス浄化用触媒の触媒担体として用いた場合において、必要とされる浄化性能を満たし得る大きさを適宜選択することができる。   The shape of the honeycomb structure 10 is not particularly limited. For example, the cylindrical shape of the bottom surface (cylindrical shape), the cylindrical shape of the oval shape of the bottom surface, and the polygonal shape of the bottom surface (square, pentagon, hexagon, heptagon, octagon) Etc.). Further, the size of the honeycomb structure 10 is not particularly limited, and when used as a catalyst carrier of an exhaust gas purification catalyst, a size capable of satisfying the required purification performance can be appropriately selected.

ハニカム構造体10を構成する材料としては、セラミックスを主成分とする材料、又は焼結金属等を好適例として挙げることができる。また、ハニカム構造体が、セラミックスを主成分とする材料からなるものである場合、そのセラミックスとしては、炭化珪素、コージェライト、アルミナタイタネート、サイアロン、ムライト、窒化珪素、リン酸ジルコニウム、ジルコニア、チタニア、アルミナ、シリカ、ゼオライト若しくはバナジウム等又はこれらを組み合わせたものを好適例として挙げることができる。   As a material which comprises the honeycomb structure 10, the material which has ceramics as a main component, or a sintered metal can be mentioned as a suitable example. When the honeycomb structure is made of a material mainly composed of ceramics, the ceramics include silicon carbide, cordierite, alumina titanate, sialon, mullite, silicon nitride, zirconium phosphate, zirconia, titania. Preferred examples include alumina, silica, zeolite, vanadium, or a combination thereof.

(2)排ガス浄化用触媒:
図4は、本発明の排ガス浄化用触媒の一の実施形態の、セルの延びる方向に垂直な断面の一部を示す部分断面図である。図5は、本発明の排ガス浄化用触媒の一の実施形態の、セルの延びる方向に平行な断面を示す断面図である。
(2) Exhaust gas purification catalyst:
FIG. 4 is a partial cross-sectional view showing a part of a cross section perpendicular to the cell extending direction of one embodiment of the exhaust gas purifying catalyst of the present invention. FIG. 5 is a cross-sectional view showing a cross section parallel to the cell extending direction of one embodiment of the exhaust gas purifying catalyst of the present invention.

本発明の排ガス浄化用触媒20は、本発明のハニカム構造体10を触媒担体とし、そのハニカム構造体10の隔壁14上に、排ガス中の有害物質の浄化を促進する触媒成分を含有する触媒層21が担持されてなるものである。   The exhaust gas purifying catalyst 20 of the present invention uses the honeycomb structure 10 of the present invention as a catalyst carrier, and on the partition walls 14 of the honeycomb structure 10, a catalyst layer containing a catalyst component that promotes purification of harmful substances in the exhaust gas. 21 is carried.

これまで説明したように、本発明のハニカム構造体10は、高い昇温性と高い保温性及び強度とを両立することができるものである。したがって、本発明の排ガス浄化用触媒20は、触媒担体であるハニカム構造体10の高い昇温性により、触媒層21中の触媒成分を、迅速に活性温度まで上昇させることができ、高いライトオフ性を発揮する。また、触媒担体であるハニカム構造体10の高い保温性により、触媒層21中の触媒成分を活性温度まで上昇させた後、その活性温度を維持することが容易である。更に、触媒担体であるハニカム構造体10の高い強度により、キャニング時の損傷が生じ難い。   As described so far, the honeycomb structure 10 of the present invention can achieve both high temperature rising property and high heat retention and strength. Therefore, the exhaust gas-purifying catalyst 20 of the present invention can rapidly raise the catalyst component in the catalyst layer 21 to the activation temperature due to the high temperature rise property of the honeycomb structure 10 which is a catalyst carrier, and has a high light-off. Demonstrate sex. Further, due to the high heat retention of the honeycomb structure 10 as the catalyst carrier, it is easy to maintain the activation temperature after raising the catalyst component in the catalyst layer 21 to the activation temperature. Furthermore, due to the high strength of the honeycomb structure 10 as a catalyst carrier, damage during canning hardly occurs.

触媒層21に含有される触媒成分の種類は特に限定されないが、例えば、自動車排ガス浄化用途に用いる場合、貴金属を用いることが好ましい。この貴金属としては、Pt、Rh若しくはPd、又はこれらを組み合わせたものを好適例として挙げることができる。   Although the kind of catalyst component contained in the catalyst layer 21 is not particularly limited, for example, when used for automobile exhaust gas purification, it is preferable to use a noble metal. Preferred examples of the noble metal include Pt, Rh, Pd, or a combination thereof.

貴金属等の触媒成分は、隔壁14上に高分散状態で担持させるため、予めAlのような比表面積の大きな耐熱性無機酸化物に一旦担持させた後、ハニカム構造体の隔壁に担持することが好ましい。尚、触媒成分を担持させる耐熱性無機酸化物としては、Al以外に、用途によってはゼオライト等を用いることもできる。また、貴金属等の触媒成分は、CeO、ZrO、あるいはこれらの複合酸化物等からなる助触媒に固定化した上で、ハニカム構造体10の隔壁14上に担持してもよい。 Catalyst components such as noble metals are supported on the partition walls 14 in a highly dispersed state, so that they are first supported on a heat-resistant inorganic oxide having a large specific surface area such as Al 2 O 3 and then supported on the partition walls of the honeycomb structure. It is preferable to do. In addition to Al 2 O 3 , zeolite or the like can be used as the heat-resistant inorganic oxide for supporting the catalyst component, depending on the application. Further, a catalyst component such as a noble metal may be supported on the partition wall 14 of the honeycomb structure 10 after being fixed to a promoter composed of CeO 2 , ZrO 2 , or a composite oxide thereof.

(3)ハニカム構造体の製造方法:
本発明のハニカム構造体は、基本的に、従来公知のハニカム構造体の製造方法と同様の製造方法により製造することができる。即ち、前記のような九角形のセル形状に対応した形状の成形用口金を使用する以外は、従来公知のハニカム構造体の製造方法と同様に、押出成形法等により、ハニカム状の成形体(ハニカム成形体)を得、これを乾燥、焼成することにより製造することができる。
(3) Manufacturing method of honeycomb structure:
The honeycomb structure of the present invention can basically be manufactured by a manufacturing method similar to a conventionally known method for manufacturing a honeycomb structure. That is, except for using a molding die having a shape corresponding to the nine-sided cell shape as described above, a honeycomb-shaped molded body ( Honeycomb molded body) is obtained, and this can be produced by drying and firing.

ハニカム成形体の成形原料は、主成分となるセラミックス等の粉末に、バインダ、界面活性剤、造孔材、水等を添加して作製する。   A forming raw material of the honeycomb formed body is prepared by adding a binder, a surfactant, a pore former, water, or the like to a powder such as ceramics as a main component.

バインダとしては、メチルセルロース、ヒドロキシプロピルメチルセルロース、ヒドロキシプロポキシルセルロース、ヒドロキシエチルセルロース、カルボキシメチルセルロース、ポリビニルアルコール等を挙げることができる。バインダの含有量は、主成分となるセラミックス等の粉末の質量を100質量部としたときに、2.0〜10.0質量部であることが好ましい。   Examples of the binder include methyl cellulose, hydroxypropyl methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. The content of the binder is preferably 2.0 to 10.0 parts by mass when the mass of powder such as ceramics as a main component is 100 parts by mass.

水の含有量は、主成分となるセラミックス等の粉末の質量を100質量部としたときに、20〜60質量部であることが好ましい。   The water content is preferably 20 to 60 parts by mass when the mass of the powder such as ceramics as the main component is 100 parts by mass.

界面活性剤としては、エチレングリコール、デキストリン、脂肪酸石鹸、ポリアルコール等を用いることができる。界面活性剤の含有量は、主成分となるセラミックス等の粉末の質量を100質量部としたときに、0.1〜2.0質量部であることが好ましい。   As the surfactant, ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like can be used. The content of the surfactant is preferably 0.1 to 2.0 parts by mass when the mass of the powder such as ceramic as the main component is 100 parts by mass.

造孔材としては、グラファイト、澱粉、発泡樹脂、吸水性樹脂、シリカゲル等を用いることができる。造孔材の含有量は、主成分となるセラミックス等の質量を100質量部としたときに、0.5〜10.0質量部であることが好ましい。   As the pore former, graphite, starch, foamed resin, water absorbent resin, silica gel or the like can be used. The content of the pore former is preferably 0.5 to 10.0 parts by mass when the mass of the ceramics as a main component is 100 parts by mass.

成形原料は、ニーダー、真空土練機等で混練することにより坏土となり、この坏土を用いて、押出成形法等により、ハニカム成形体を成形する。   The forming raw material is kneaded by a kneader, a vacuum kneader, or the like, and a honeycomb formed body is formed by extrusion molding or the like using this kneaded material.

ハニカム成形体の乾燥方法は特に限定されず、例えば、マイクロ波加熱乾燥、高周波誘電加熱乾燥等の電磁波加熱方式の乾燥方法や、熱風乾燥、過熱水蒸気乾燥等の外部加熱方式の乾燥方法を用いることができる。電磁波加熱方式の乾燥方法で一定量の水分を乾燥させた後、残りの水分を外部加熱方式の乾燥方法により乾燥させるようにしてもよい。   The drying method of the honeycomb formed body is not particularly limited. For example, an electromagnetic heating method drying method such as microwave heating drying or high frequency dielectric heating drying, or an external heating method drying method such as hot air drying or superheated steam drying is used. Can do. After a certain amount of moisture is dried by the electromagnetic heating method drying method, the remaining moisture may be dried by the external heating method drying method.

乾燥後のハニカム成形体(ハニカム乾燥体)の焼成は、電気炉、ガス炉等を用いて行う。焼成雰囲気、焼成温度、焼成時間等の焼成条件は、ハニカム乾燥体の構成材料等に応じて適宜決定することができる。   Firing of the dried honeycomb formed body (honeycomb dry body) is performed using an electric furnace, a gas furnace, or the like. Firing conditions such as a firing atmosphere, a firing temperature, and a firing time can be appropriately determined according to the constituent material of the honeycomb dried body.

(4)排ガス浄化用触媒の製造方法:
本発明の排ガス浄化用触媒は、前記のようにして製造されたハニカム構造体の隔壁上に、触媒層を担持させることにより製造することができる。具体的には、まず、触媒成分を含有する触媒スラリーを調製する。この触媒スラリーを、ディッピング法、吸引法等の方法を用いて、ハニカム構造体の隔壁上にコートした後、乾燥、焼成することにより、触媒スラリーに含有される成分を、触媒層として隔壁上に固定する。触媒スラリーの調製は、例えば、触媒成分としてPdを担持させる場合、まず、比表面積200m/g程度のγ−Al粉末に、Pd(NO)水溶液等を用いてPd含浸し、乾燥後、500℃程度の温度で焼成してPd担持Al粉末とする。次いで、このPd担持Al粉末に水と酢酸とを適量加え、湿式解砕することにより触媒スラリーを調製する。
(4) Manufacturing method of exhaust gas purification catalyst:
The exhaust gas purifying catalyst of the present invention can be produced by supporting a catalyst layer on the partition walls of the honeycomb structure produced as described above. Specifically, first, a catalyst slurry containing a catalyst component is prepared. The catalyst slurry is coated on the partition walls of the honeycomb structure using a dipping method, a suction method, or the like, and then dried and fired, whereby components contained in the catalyst slurry are formed on the partition walls as a catalyst layer. Fix it. For example, when Pd is supported as a catalyst component, the catalyst slurry is first impregnated with γ-Al 2 O 3 powder having a specific surface area of about 200 m 2 / g using a Pd (NO 3 ) 2 aqueous solution or the like. After drying, it is fired at a temperature of about 500 ° C. to obtain Pd-supported Al 2 O 3 powder. Next, an appropriate amount of water and acetic acid is added to the Pd-supported Al 2 O 3 powder, and wet pulverization is performed to prepare a catalyst slurry.

以下、本発明を実施例により更に具体的に説明するが、本発明は、これらの実施例によって何ら限定されるものではない。   EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(実施例1〜9)
コージェライト化原料100質量部に対し、造孔剤として発泡樹脂を5.0質量部、バインダとしてメチルセルロースを5.0質量部、界面活性剤としてエチレングリコールを1.0質量部、分散媒として水を40質量部加えて混練することにより杯土を調製した。ここで、「コージェライト化原料」とは、焼成によりコージェライトとなる原料を意味する。本実施例では、コージェライト化原料として、タルク41質量%、カオリン19質量%、アルミニウム酸化物25質量%、及びシリカ15質量%を混合したものを使用した。こうして調製した坏土を、真空脱気した後、図1に示すような九角形のセル形状が得られる成形用口金を用いて押出成形することによりハニカム成形体を得た。次に、得られたハニカム成形体をマイクロ波乾燥機で乾燥し、更に熱風乾燥機で完全に乾燥させて、ハニカム乾燥体とした。次いで、このハニカム乾燥体を、最高温度1400〜1430℃の温度範囲で焼成することにより、セル形状が九角形で、図3に示す距離aの値がそれぞれ表1に示す値となるような、実施例1〜9のハニカム構造体を得た。尚、表1に示すように、体積(セル部分も含む全体積)、隔壁の厚さ及びセル密度は、実施例1〜9のハニカム構造体の何れにおいても同一である。
(Examples 1-9)
For 100 parts by mass of the cordierite forming material, 5.0 parts by mass of foamed resin as a pore-forming agent, 5.0 parts by mass of methylcellulose as a binder, 1.0 part by mass of ethylene glycol as a surfactant, and water as a dispersion medium 40 parts by mass was added and kneaded to prepare a clay. Here, “cordierite raw material” means a raw material that becomes cordierite by firing. In this example, as a cordierite forming raw material, a mixture of 41% by mass of talc, 19% by mass of kaolin, 25% by mass of aluminum oxide, and 15% by mass of silica was used. The thus prepared kneaded material was vacuum degassed and then extrusion molded using a molding die capable of obtaining a hexagonal cell shape as shown in FIG. 1 to obtain a honeycomb formed body. Next, the obtained honeycomb formed body was dried with a microwave dryer and further completely dried with a hot air dryer to obtain a honeycomb dried body. Next, the honeycomb dried body is fired at a maximum temperature of 1400 to 1430 ° C., so that the cell shape is a hexagonal shape, and the values of the distance a shown in FIG. The honeycomb structures of Examples 1 to 9 were obtained. As shown in Table 1, the volume (the entire volume including the cell portion), the partition wall thickness, and the cell density are the same in any of the honeycomb structures of Examples 1-9.

(比較例1)
図7に示すような六角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が六角形で、体積、隔壁の厚さ及びセル密度が、実施例1〜9のハニカム構造体と同一である比較例1のハニカム構造体を得た。
(Comparative Example 1)
Except for using a die for forming a hexagonal cell shape as shown in FIG. 7, the cell shape is hexagonal, and the volume, partition wall thickness, and cell density are the same as in Examples 1-9. A honeycomb structure of Comparative Example 1 that was the same as the honeycomb structures of Examples 1 to 9 was obtained.

(比較例2)
図8に示すような十二角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が十二角形で、体積、隔壁の厚さ及びセル密度が、実施例1〜9のハニカム構造体と同一である比較例2のハニカム構造体を得た。
(Comparative Example 2)
Except for using a die for forming a dodecagonal cell shape as shown in FIG. 8, the cell shape is a dodecagon, volume, partition wall thickness, and cell, in the same manner as in Examples 1-9. A honeycomb structure of Comparative Example 2 having the same density as the honeycomb structures of Examples 1 to 9 was obtained.

(評価)
実施例1〜9並びに比較例1及び2のハニカム構造体について、下記の方法で、昇温性、保温性及び強度の評価を行い、その結果を表1に示した。
(Evaluation)
The honeycomb structures of Examples 1 to 9 and Comparative Examples 1 and 2 were evaluated for temperature rise, heat retention and strength by the following methods, and the results are shown in Table 1.

[昇温性及び保温性の評価方法]
昇温性及び保温性の評価方法を、図6を参照して説明する。まず、室温(25℃)のハニカム構造体に、700℃の空気を一定流量で流して、ハニカム構造体を昇温させ、ハニカム構造体の温度が700℃に達した時点で、今度は、室温(25℃)の空気を一定流量で流して、ハニカム構造体の温度を室温まで降温させた。そして、ハニカム構造体の温度が、昇温時に500℃に達した時間T1と、降温時に500まで下がった時間T2とを測定した。尚、T1及びT2は、何れも700℃の空気を流し始めた時点から測定した時間である。こうして測定されたT1は、ハニカム構造体の昇温性を示すものであり、T1が短い程、昇温性が高いと言える。また、室温の空気を流し始めてから、ハニカム構造体の温度が500℃に下がるまでの時間がハニカム構造体の保温性を示すものであり、長いほど保温性が高いと言える。そして、T2からT1を差し引いた時間(T2−T1)は、ハニカム構造体に触媒層を担持させた場合の触媒活性温度である500℃の保持時間を示す。つまり、昇温性、保温性が共に高いと、T2−T1が長くなり、長時間に渡って安定的に高い排ガスの浄化性能を維持できることになる。
[Method for evaluating temperature rise and heat retention]
A method for evaluating the temperature rise property and the heat retention property will be described with reference to FIG. First, air at a constant flow rate of 700 ° C. is passed through the honeycomb structure at room temperature (25 ° C.) to raise the temperature of the honeycomb structure, and when the temperature of the honeycomb structure reaches 700 ° C., this time, (25 ° C.) air was allowed to flow at a constant flow rate to lower the temperature of the honeycomb structure to room temperature. Then, a time T1 when the temperature of the honeycomb structure reached 500 ° C. when the temperature was raised and a time T2 when the temperature was lowered to 500 when the temperature was lowered were measured. T1 and T2 are times measured from the time when air at 700 ° C. starts to flow. T1 measured in this way shows the temperature rise property of a honeycomb structure, and it can be said that temperature rise property is so high that T1 is short. The time from the start of flowing room temperature air until the temperature of the honeycomb structure decreases to 500 ° C. indicates the heat retention of the honeycomb structure, and it can be said that the longer the temperature, the higher the heat retention. And the time (T2-T1) which subtracted T1 from T2 shows the holding time of 500 degreeC which is a catalyst active temperature at the time of making a honeycomb structure carry | support a catalyst layer. That is, if both the temperature raising property and the heat retaining property are high, T2-T1 becomes long, and high exhaust gas purification performance can be stably maintained for a long time.

[強度の評価方法]
フレキシブルチューブ内にハニカム構造体を挿入して、水圧による均等圧を掛け、部分破壊を生じた圧力を測定し、これをハニカム構造体のアイソスタティック強度とした。尚、測定結果は、比較例1のハニカム構造体についての測定値を1.0として、相対表示した。
[Strength evaluation method]
The honeycomb structure was inserted into the flexible tube, and an equal pressure by water pressure was applied to measure the pressure at which partial fracture occurred, and this was defined as the isostatic strength of the honeycomb structure. In addition, the measurement result was displayed relative to the measurement value of the honeycomb structure of Comparative Example 1 as 1.0.

Figure 2014064997
Figure 2014064997

(考察)
表1に示す結果から、実施例のようにセル形状を特定の九角形にすることで、セル形状が六角形である比較例1と比べて、特に保温性が向上し、T2−T1が長くなることがわかる。また、実施例のようにセル形状を特定の九角形にすることで、セル形状が十二角形である比較例2と比べて、T2−T1をほぼ同等としつつ、昇温性を大幅に改善できるか(実施例1〜4)、若しくは、T2−T1を大幅に改善でき、排ガス浄化性能の向上が期待できる。特に、実施例1〜9の内、距離aの値が下式(1)を満たしている実施例2〜7の昇温性は、セル形状が十二角形である比較例2の昇温性よりも高く、セル形状が六角形である比較例1の昇温性と比べても大きな差がない(T1の差が10秒以内)ことがわかる。また、これら実施例2〜7の保温性は、セル形状が六角形である比較例1の保温性よりも高く、セル形状が十二角形である比較例2の保温性と比べても、同等以上であることがわかる。更に、これら実施例2〜7の強度は、セル形状が六角形である比較例1の強度よりも高いことがわかる。
0.2p≦a≦0.7p ・・・(1)
(Discussion)
From the results shown in Table 1, by making the cell shape a specific hexagon as in the example, the heat retention is particularly improved and T2-T1 is longer compared to Comparative Example 1 in which the cell shape is a hexagon. I understand that In addition, by making the cell shape a specific nine-sided shape as in the example, compared with Comparative Example 2 in which the cell shape is a dodecagon, T2-T1 is substantially the same, and the temperature rise performance is greatly improved. (Examples 1 to 4) or T2-T1 can be significantly improved, and improvement in exhaust gas purification performance can be expected. In particular, among Examples 1 to 9, the temperature increase performance of Examples 2 to 7 in which the value of the distance a satisfies the following formula (1) is the temperature increase performance of Comparative Example 2 in which the cell shape is a dodecagon. It can be seen that there is no significant difference (the difference in T1 is within 10 seconds) compared to the temperature rise performance of Comparative Example 1 in which the cell shape is hexagonal. Moreover, the heat retention of these Examples 2-7 is higher than the heat retention of the comparative example 1 whose cell shape is a hexagon, and it is equivalent compared with the heat retention of the comparative example 2 whose cell shape is a dodecagon. It turns out that it is above. Furthermore, it turns out that the intensity | strength of these Examples 2-7 is higher than the intensity | strength of the comparative example 1 whose cell shape is a hexagon.
0.2p ≦ a ≦ 0.7p (1)

(実施例10)
実施例1〜9と同様にして、セル形状が九角形で、図3に示す距離aの値が0.5pであり、体積、隔壁の厚さ、セル密度、開口率、質量及び熱容量が、表2に示す値である実施例10のハニカム構造体を得た。
(Example 10)
In the same manner as in Examples 1 to 9, the cell shape is a hexagon, the value of the distance a shown in FIG. 3 is 0.5 p, the volume, the partition wall thickness, the cell density, the aperture ratio, the mass, and the heat capacity are A honeycomb structure of Example 10 having the values shown in Table 2 was obtained.

(比較例3)
図7に示すような六角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が六角形で、体積、隔壁の厚さ及びセル密度が、実施例10のハニカム構造体と同一である比較例3のハニカム構造体を得た。
(Comparative Example 3)
Except for using a die for forming a hexagonal cell shape as shown in FIG. 7, the cell shape is hexagonal, and the volume, partition wall thickness, and cell density are the same as in Examples 1-9. A honeycomb structure of Comparative Example 3 that is the same as the honeycomb structure of Example 10 was obtained.

(比較例4)
図8に示すような十二角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が十二角形で、体積、隔壁の厚さ及びセル密度が、実施例10のハニカム構造体と同一である比較例4のハニカム構造体を得た。
(Comparative Example 4)
Except for using a die for forming a dodecagonal cell shape as shown in FIG. 8, the cell shape is a dodecagon, volume, partition wall thickness, and cell, in the same manner as in Examples 1-9. A honeycomb structure of Comparative Example 4 having the same density as the honeycomb structure of Example 10 was obtained.

(評価)
実施例10並びに比較例3及び4のハニカム構造体について、前記の方法で、昇温性、保温性及び強度の評価を行い、その結果を表2に示した。但し、アイソスタティック強度の測定結果は、比較例3のハニカム構造体についての測定値を1.0として、相対表示した。
(Evaluation)
The honeycomb structures of Example 10 and Comparative Examples 3 and 4 were evaluated for the temperature rise property, the heat retaining property and the strength by the above-mentioned methods, and the results are shown in Table 2. However, the measurement result of isostatic strength was displayed relative to the measurement value of the honeycomb structure of Comparative Example 3 as 1.0.

Figure 2014064997
Figure 2014064997

(考察)
表2に示す結果から、実施例10の昇温性は、セル形状が十二角形である比較例4の昇温性よりも高く、セル形状が六角形である比較例3の昇温性と比べても大きな差がない(T1の差が10秒以内)ことがわかる。また、実施例10の保温性は、セル形状が六角形である比較例3及びセル形状が十二角形である比較例4の保温性よりも高いことがわかる。更に、実施例10の強度は、セル形状が六角形である比較例3の強度よりも高く、セル形状が十二角形である比較例4の強度と同等であることがわかる。
(Discussion)
From the results shown in Table 2, the temperature rise performance of Example 10 is higher than that of Comparative Example 4 whose cell shape is a dodecagon, and the temperature rise performance of Comparative Example 3 whose cell shape is a hexagon. It can be seen that there is no significant difference even when compared (the difference in T1 is within 10 seconds). Moreover, it turns out that the heat retention of Example 10 is higher than the heat retention of the comparative example 3 whose cell shape is a hexagon, and the comparative example 4 whose cell shape is a dodecagon. Furthermore, it can be seen that the strength of Example 10 is higher than the strength of Comparative Example 3 in which the cell shape is a hexagon, and is equivalent to the strength of Comparative Example 4 in which the cell shape is a dodecagon.

(実施例11)
実施例1〜9と同様にして、セル形状が九角形で、図3に示す距離aの値が0.5pであり、体積、隔壁の厚さ、セル密度、開口率、質量及び熱容量が、表3に示す値である実施例11のハニカム構造体を得た。
(Example 11)
In the same manner as in Examples 1 to 9, the cell shape is a hexagon, the value of the distance a shown in FIG. 3 is 0.5 p, the volume, the partition wall thickness, the cell density, the aperture ratio, the mass, and the heat capacity are A honeycomb structure of Example 11 having the values shown in Table 3 was obtained.

(比較例5)
図7に示すような六角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が六角形で、体積、隔壁の厚さ及びセル密度が、実施例11のハニカム構造体と同一である比較例5のハニカム構造体を得た。
(Comparative Example 5)
Except for using a die for forming a hexagonal cell shape as shown in FIG. 7, the cell shape is hexagonal, and the volume, partition wall thickness, and cell density are the same as in Examples 1-9. A honeycomb structure of Comparative Example 5 that is the same as the honeycomb structure of Example 11 was obtained.

(比較例6)
図8に示すような十二角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が十二角形で、体積、隔壁の厚さ及びセル密度が、実施例11のハニカム構造体と同一である比較例6のハニカム構造体を得た。
(Comparative Example 6)
Except for using a die for forming a dodecagonal cell shape as shown in FIG. 8, the cell shape is a dodecagon, volume, partition wall thickness, and cell, in the same manner as in Examples 1-9. A honeycomb structure of Comparative Example 6 having the same density as that of Example 11 was obtained.

(評価)
実施例11並びに比較例5及び6のハニカム構造体について、前記の方法で、昇温性、保温性及び強度の評価を行い、その結果を表3に示した。但し、アイソスタティック強度の測定結果は、比較例5のハニカム構造体についての測定値を1.0として、相対表示した。
(Evaluation)
With respect to the honeycomb structures of Example 11 and Comparative Examples 5 and 6, the temperature rise property, heat retention property and strength were evaluated by the above-described methods, and the results are shown in Table 3. However, the measurement result of the isostatic strength was displayed relative to the measurement value of the honeycomb structure of Comparative Example 5 as 1.0.

Figure 2014064997
Figure 2014064997

(考察)
表3に示す結果から、実施例11の昇温性は、セル形状が十二角形である比較例6の昇温性よりも高く、セル形状が六角形である比較例5の昇温性と比べても大きな差がない(T1の差が10秒以内)ことがわかる。また、実施例11の保温性は、セル形状が六角形である比較例5及びセル形状が十二角形である比較例6の保温性よりも高いことがわかる。更に、実施例11の強度は、セル形状が六角形である比較例5の強度よりも高く、セル形状が十二角形である比較例6の強度と同等であることがわかる。
(Discussion)
From the results shown in Table 3, the temperature rise performance of Example 11 is higher than that of Comparative Example 6 in which the cell shape is a dodecagon, and the temperature rise performance of Comparative Example 5 in which the cell shape is a hexagon. It can be seen that there is no significant difference even when compared (the difference in T1 is within 10 seconds). Moreover, it turns out that the heat retention of Example 11 is higher than the heat retention of the comparative example 5 whose cell shape is a hexagon, and the comparative example 6 whose cell shape is a dodecagon. Further, it can be seen that the strength of Example 11 is higher than the strength of Comparative Example 5 in which the cell shape is a hexagon, and is equivalent to the strength of Comparative Example 6 in which the cell shape is a dodecagon.

(実施例12)
実施例1〜9と同様にして、セル形状が九角形で、図3に示す距離aの値が0.5pであり、体積、隔壁の厚さ、セル密度、開口率、質量及び熱容量が、表4に示す値である実施例12のハニカム構造体を得た。
(Example 12)
In the same manner as in Examples 1 to 9, the cell shape is a hexagon, the value of the distance a shown in FIG. 3 is 0.5 p, the volume, the partition wall thickness, the cell density, the aperture ratio, the mass, and the heat capacity are A honeycomb structure of Example 12 having the values shown in Table 4 was obtained.

(比較例7)
図7に示すような六角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が六角形で、体積、隔壁の厚さ及びセル密度が、実施例12のハニカム構造体と同一である比較例7のハニカム構造体を得た。
(Comparative Example 7)
Except for using a die for forming a hexagonal cell shape as shown in FIG. 7, the cell shape is hexagonal, and the volume, partition wall thickness, and cell density are the same as in Examples 1-9. A honeycomb structure of Comparative Example 7 that is the same as the honeycomb structure of Example 12 was obtained.

(比較例8)
図8に示すような十二角形のセル形状が得られる成形用口金を用いた以外は、実施例1〜9と同様にして、セル形状が十二角形で、体積、隔壁の厚さ及びセル密度が、実施例12のハニカム構造体と同一である比較例8のハニカム構造体を得た。
(Comparative Example 8)
Except for using a die for forming a dodecagonal cell shape as shown in FIG. 8, the cell shape is a dodecagon, volume, partition wall thickness, and cell, in the same manner as in Examples 1-9. A honeycomb structure of Comparative Example 8 having the same density as that of Example 12 was obtained.

(評価)
実施例12並びに比較例7及び8のハニカム構造体について、前記の方法で、昇温性、保温性及び強度の評価を行い、その結果を表4に示した。但し、アイソスタティック強度の測定結果は、比較例7のハニカム構造体についての測定値を1.0として、相対表示した。
(Evaluation)
With respect to the honeycomb structures of Example 12 and Comparative Examples 7 and 8, the temperature rise property, heat retention property and strength were evaluated by the above-described methods, and the results are shown in Table 4. However, the measurement result of isostatic strength was displayed relative to the measurement value of the honeycomb structure of Comparative Example 7 as 1.0.

Figure 2014064997
Figure 2014064997

(考察)
表4に示す結果から、実施例12の昇温性は、セル形状が十二角形である比較例8の昇温性よりも高く、セル形状が六角形である比較例7の昇温性と比べても大きな差がない(T1の差が10秒以内)ことがわかる。また、実施例12の保温性は、セル形状が六角形である比較例7及びセル形状が十二角形である比較例8の保温性よりも高いことがわかる。更に、実施例12の強度は、セル形状が六角形である比較例7の強度よりも高く、セル形状が十二角形である比較例8の強度とほぼ同等であることがわかる。
(Discussion)
From the results shown in Table 4, the temperature rise performance of Example 12 is higher than that of Comparative Example 8 in which the cell shape is a dodecagon, and the temperature rise performance of Comparative Example 7 in which the cell shape is a hexagon. It can be seen that there is no significant difference even when compared (the difference in T1 is within 10 seconds). Moreover, it turns out that the heat retention of Example 12 is higher than the heat retention of the comparative example 7 whose cell shape is a hexagon, and the comparative example 8 whose cell shape is a dodecagon. Furthermore, it can be seen that the strength of Example 12 is higher than the strength of Comparative Example 7 in which the cell shape is a hexagon, and is substantially equal to the strength of Comparative Example 8 in which the cell shape is a dodecagon.

本発明は、自動車等の排ガスを浄化するために使用される排ガス浄化用触媒又はその触媒担体として、好適に利用することができる。   INDUSTRIAL APPLICABILITY The present invention can be suitably used as an exhaust gas purifying catalyst used for purifying exhaust gas from automobiles or the like or a catalyst carrier thereof.

1(1A,1B,1C):頂点、2(2A,2B,2C):頂点、3(3A,3B,3C,3D,3E,3F):頂点、4(4A,4B,4C):対角線、5(5A,5B,5C):線分、6(6A,6B,6C):角部、10:ハニカム構造体、11:入口端面、12:出口端面、13:セル、14:隔壁、16:交点部、17:交点部、20:排ガス浄化用触媒、21:触媒層、30:ハニカム構造体、34:隔壁、36:交点部、40:ハニカム構造体、44:隔壁、46:交点部。 1 (1A, 1B, 1C): Vertex 2 (2A, 2B, 2C): Vertex 3 (3A, 3B, 3C, 3D, 3E, 3F): Vertex 4 (4A, 4B, 4C): Diagonal line, 5 (5A, 5B, 5C): line segment, 6 (6A, 6B, 6C): corner, 10: honeycomb structure, 11: inlet end surface, 12: outlet end surface, 13: cell, 14: partition wall, 16: Intersection, 17: Intersection, 20: Exhaust gas purifying catalyst, 21: Catalyst layer, 30: Honeycomb structure, 34: Partition, 36: Intersection, 40: Honeycomb, 44: Partition, 46: Intersection

Claims (4)

流体の入口側となる入口端面から流体の出口側となる出口端面まで延びる複数のセルを区画形成する多孔質の隔壁を有し、
前記セルの延びる方向に垂直な断面における前記セルの形状が九角形であり、
前記九角形が、正六角形の6つの頂点の内、当該正六角形の周方向において1つ置きに存在する3つの頂点と、当該3つの頂点を結ぶそれぞれの対角線と平行で、両端が残りの3つの頂点をそれぞれ形成する辺上に在る線分によって、前記残りの3つの頂点を含む角部が切断されることにより形成された6つの新たな頂点とを有する形状であり、
隣接するセル間において、前記新たな頂点と前記新たな頂点以外の頂点とを結ぶ辺同士が平行な状態で対向するように、前記複数のセルが配置されており、
排ガス浄化用触媒の触媒担体として用いられるハニカム構造体。
A porous partition wall defining a plurality of cells extending from an inlet end surface serving as a fluid inlet side to an outlet end surface serving as a fluid outlet side;
The shape of the cell in a cross section perpendicular to the cell extending direction is a hexagon,
Of the six vertices of the regular hexagon, the nine-sided hexagon is parallel to the three vertices that exist every other in the circumferential direction of the regular hexagon, and the diagonal lines connecting the three vertices, and both ends are the remaining three. A shape having six new vertices formed by cutting corners including the remaining three vertices by line segments on the sides forming the respective vertices;
Between the adjacent cells, the plurality of cells are arranged so that the sides connecting the new vertex and the vertex other than the new vertex face each other in parallel,
A honeycomb structure used as a catalyst carrier for an exhaust gas purification catalyst.
前記線分が、前記残りの3つの頂点から前記線分までの距離をaとし、前記残りの3つの頂点から前記対角線までの距離をpとしたときに、下式(1)の関係を満たすものである請求項1に記載のハニカム構造体。
0.2p≦a≦0.7p ・・・(1)
When the distance from the remaining three vertices to the line segment is a and the distance from the remaining three vertices to the diagonal line is p, the line segment satisfies the relationship of the following expression (1). The honeycomb structure according to claim 1, wherein the honeycomb structure is one.
0.2p ≦ a ≦ 0.7p (1)
前記隔壁の厚さが、38〜305μmである請求項1又は2に記載のハニカム構造体。   The honeycomb structure according to claim 1 or 2, wherein the partition wall has a thickness of 38 to 305 µm. 請求項1〜3の何れか一項に記載のハニカム構造体の前記隔壁上に、排ガス中の有害物質の浄化を促進する触媒成分を含有する触媒層が担持されてなる排ガス浄化用触媒。   A catalyst for exhaust gas purification, wherein a catalyst layer containing a catalyst component that promotes purification of harmful substances in exhaust gas is supported on the partition walls of the honeycomb structure according to any one of claims 1 to 3.
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