Ibiden Company Limited

Atsushi Kudo

Masafumi Kunieda

Kazushige Ohno

Kazutake Ogyu

A honeycomb filter includes a ceramic laminated body including columnar porous ceramic members and an adhesive layer combining the columnar porous ceramic members with one another. The columnar porous ceramic members each have a partition wall and through holes, the through holes extend in parallel with one another in a length direction of the columnar porous ceramic members, the partition wall separates the through holes and filters particulates in an exhaust gas, and the adhesive layer includes an inorganic binder, an inorganic fiber, inorganic particles and an inorganic balloon.

Honeycomb filter for purifying exhaust gases, adhesive, coating material, and manufacturing method of honeycomb filter for purifying exhaust gases

An object of the present invention is to provide a honeycomb filter for purifying exhaust gases which makes it possible to alleviate a thermal stress generated due to occurrence of a local temperature change and which is less likely to generate cracks and superior in strength and durability, an adhesive that has a low thermal capacity and is capable of alleviating the thermal stress, a coating material that has a low thermal capacity with a superior heat insulating property and is capable of alleviating the thermal stress, and a manufacturing method of the honeycomb filter for purifying exhaust gases that can improve precision in the outside dimension, and reduce damages in the manufacturing processes. The present invention relates to a honeycomb filter for purifying exhaust gases, having a structure in that a plurality of column-shaped porous ceramic members, each having a number of through holes that are placed side by side in the length direction with partition wall interposed therebetween, are combined with one another through adhesive layers so that the partition wall that separate the through holes are allowed to function as a filter for collecting particulates, and in this structure, the thermal expansion coefficient &#x3b1;of the adhesive layer and the thermal expansion coefficient &#x3b1;of the porous ceramic member are designed to have the following relationship:0.01&#x3c;|&#x3b1;&#x2212;&#x3b1;|/&#x3b1;&#x3c;1.0.

A honeycomb filter for purifying exhaust gases includes columnar porous ceramic members and an adhesive layer combing the ceramic members with one another. Each porous ceramic member has a partition wall and through holes. The through holes are extending in parallel in length direction of the ceramic members. The partition wall is separating the through holes and filters particulates in exhaust gas. The through holes include ones sealed at inlet side of the ceramic members and ones sealed at outlet side of the ceramic members such that the exhaust gas enters from the inlet side, passes through the partition wall and flows out from the outlet side. The adhesive layer has thermal expansion coefficient &#x3b1;. The ceramic members have thermal expansion coefficient &#x3b1;. The thermal expansion coefficient &#x3b1;of the adhesive layer and the thermal expansion coefficient &#x3b1;of the ceramic members satisfy relationship, 0.01&#x3c;|&#x3b1;&#x2212;&#x3b1;|/&#x3b1;&#x3c;1.0.

Honeycomb filter for exhaust gas decontamination, adhesive, coating material and process for producing honeycomb filter for exhaust gas decontamination

A pillar-shaped honeycomb structured body comprises large-capacity through holes and small-capacity through holes, a first partition wall between two adjacent large-capacity through holes, a second partition wall between a large-capacity through holes and a small-capacity through holes adjacent to each other. Each of the plurality of large-capacity through holes and small-capacity through holes extends from a first end face to a second end face. An aperture rate &#x3b1; (%) is a ratio between the sum of the area of the large-capacity through holes at the second end face and the area of the second end face. The difference in the thickness of the first partition wall and the second partition wall is &#x3b2; (mm). The relationship between &#x3b1; and &#x3b2; satisfies the following inequalities (1) and (2): 0.0022&#x3b1;+0.0329&#x2266;&#x3b2;&#x2266;0.0071&#x3b1;+0.2553 (1), and about 35&#x2266;&#x3b1;&#x2266;about 60(2).

Honeycomb structured body

A honeycomb structured body of the present invention is a pillar-shaped honeycomb structured body comprising a large number of through holes that are longitudinally placed in parallel with one another with a partition wall therebetween, wherein the large number of through holes include a group of large-capacity through holes being sealed at one of end portions so that the sum of areas on a cross section perpendicular to the longitudinal direction is made relatively larger, and a group of small-capacity through holes being sealed at the other end portion so that the sum of areas on the cross section is made relatively smaller, and the partition wall that separates the adjacent through holes constituting the group of large-capacity through holes is provided with a selective catalyst supporting portion used for selectively supporting a catalyst.

A ceramic filter including a ceramic block having a honeycomb structure. The ceramic block has one or more filter units which is a porous ceramic sintered body. The filter units are joined to each other by a sealing material layer. The ceramic block has different porosities, different pore size, different strengths, different lengths, different catalysts or different amounts of catalysts at different portions of the ceramic block.

Ceramic filter and exhaust gas decontamination unit

A honeycomb structural body comprises one or plural pillar-shaped porous ceramic members in which many through-holes are arranged side by side in a longitudinal direction through partition walls and either one end portions of these through-holes are sealed. The partition wall forming the structural body has a surface roughness of not less than 10 &#x3bc;m as a maximum roughness Rz defined in JIS B0601-2001 and an average pore size of 5-100 &#x3bc;m in a pore distribution measured by a mercury pressure method, and satisfies the following relationship:90&#x2212;/20 or100&#x2212;/20when a ratio pores having a pore size of 0.9-1.1 times the average pore size to total pore volume is A (%) and a thickness of the partition wall is B (&#x3bc;m), and there is proposed an effective honeycomb structural body having excellent pressure loss and catching efficiency and a high catalyst reactivity.

Ceramic honeycomb structure

A honeycomb structural body is constituted with a ceramic block comprising a plurality of through-holes arranged in a longitudinal direction and separated from each other through partition walls, either end portions of which through-holes being sealed. The ceramic block constituting the honeycomb structural body is made of a composite material consisting of ceramic particles and crystalline silicon and having an excellent thermal conductivity, so that the honeycomb structural body is excellent in the thermal diffusibility but also excellent in the resistance to thermal shock because the storing of thermal stress is less and no crack is caused even if a temperature distribution is caused at a relatively low temperature or cool-heat cycle is repeated over a long period of time.

Honeycomb structural body

A honeycomb filter for purifying exhaust gases, which makes it possible to alleviate a thermal stress generated due to occurrence of a local temperature change, is less likely to generate cracks, and is excellent in strength and durability. The honeycomb filter has a structure in which a plurality of column-shaped porous ceramic members, each having a number of through holes that are placed side by side in the length direction with a partition wall interposed therebetween, are combined with one another through adhesive layers so that the partition wall that separates the through holes are allowed to function as a filter for collecting particulates. A thermal expansion coefficient &#x3b1;of the adhesive layer and a thermal expansion coefficient &#x3b1;of the porous ceramic member is as follows:0.01&#x3c;|&#x3b1;&#x2212;&#x3b1;|/&#x3b1;&#x3c;1.0.

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Gifu, Japan

Atsushi Kudo