Ibiden Company Limited

Teruo Komori

Sungtae Hong

Kazushige Ohno

Yukio Oshimi

Akira Hasegawa

Noriyoshi Kakuta

Noriyuki Taoka

Takeshi Ninomiya

Hiroki Sato

An object of the present invention is to provide a honeycomb structural body which is low in pressure loss and can prolong a period up to a regenerating process. The present invention is directed to a columnar honeycomb structural body comprising a large number of through holes placed in parallel with one another in a length direction with wall portion interposed therebetween, wherein: each of the through holes has one of ends sealed; one end face of the through hole differs in opening area from the other end face thereof; a ceramic material which constitutes the wall portion has an average pore diameter in a range from 5 to 30 &#x3bc;m; and the rate of capacity of micro pores each having a pore diameter two or more times larger than the average pore diameter is set to 30% or less of the capacity of the entire micro pores.

Honeycomb structural body

An object of the present invention is to provide a honeycomb structural body with a long service life, which can reduce a pressure loss to a low level upon collecting particulates and maintain the pressure loss at the low level for a long time even after regenerating processes. The honeycomb structural body includes a columnar porous ceramic block in which a large number of through holes are placed in parallel with one another in the length direction with a wall portion interposed therebetween. Herein, the large number of through holes are constituted by a group of large-capacity through holes, each of which is sealed at one end of the honeycomb structural body so that the total sum of the areas on a cross section perpendicular to the length direction is made relatively great, and a group of small-capacity through holes, each of which is sealed at the other end of the honeycomb structural body so that the total sum of the areas on the cross section is made relatively small, and a surface roughness Rof the wall face of the through hole is set in a range from 10 to 100 &#x3bc;m.

A honeycomb structural body includes a columnar honeycomb structural body having large-capacity through holes and small-capacity through holes extending in parallel in a length direction of the columnar structural body. The large-capacity through holes and the small-capacity through holes have a polygonal shape in a cross section perpendicular to the length direction, and the large-capacity through holes and the small-capacity through holes have R-chamfered corner portions or C-chamfered corner portions in the cross section perpendicular to the length direction.

A column shaped filter having a honeycomb structure including a number of through holes extending parallel with one another in the length direction with wall portion interposed therebetween. The through holes are constituted by large-capacity through holes having a relatively larger cross-sectional area in the cross section perpendicular to the length direction and small-capacity through holes having a relatively smaller cross-sectional area in the cross section. The numbers of the two types of through holes are substantially set to the same. The large-capacity through holes are sealed at one end of the filter, while the small-capacity through holes are sealed at the other end of the filter. The large-capacity and small-capacity through holes have a ratio of partition wall length, &#x3b1;, and an aperture ratio, &#x3b2;, and &#x3b1; and &#x3b2; satisfy &#x3b2;&#x2267;(20/9)&#x3b1;+1 (where 0&#x3c;&#x3b1;&#x2266;1.5 and 1&#x3c;&#x3b2;&#x2266;6).

Filter

An object of the present invention is to provide a honeycomb structural body (filter) which has a low pressure loss upon collecting particulates, makes it possible to deposit a great amount of particulates and ashes, and is less likely to produce cracks. The columnar honeycomb structural body of the present invention includes a plurality of through holes placed in parallel with one another in the length direction, and wall portion that separates the plurality of through holes from one another and constitutes a circumferential face, wherein the plurality of through holes are composed of a group of large-capacity through holes, with one end thereof being sealed so as to cause the total of areas of cross-section perpendicular to the length direction to become relatively greater, and a group of small-capacity through holes, with the other end thereof being sealed so as to cause the total of areas of the above-mentioned cross-section to become relatively smaller, and the above-mentioned circumferential face of the columnar honeycomb structural body has a chamfered corner portion.

It is to provide a honeycomb structural body having an excellent durability, which is large in the catching amount of particulates per unit volume and does not cause uneven accumulation of ash and occurrence of cracks or the like even in use for a long period of time, and there is proposed a honeycomb structural body obtained by assembling one or plural porous ceramic members in which two kinds of through-holes consisting of a group of large volume through-holes and a group of small volume through-holes are arranged side by side in the longitudinal direction through partitions and either one ends of these through-holes are plugged, wherein the ceramic member is made of silicon-ceramic composite material consisting of ceramic and silicon.

Honeycomb structure

A filter has a honeycomb structural body having a plurality of large-capacity through holes and small-capacity through holes placed in parallel with one another in a length direction. A total (a) of lengths in the cross section of wall surfaces of one large-capacity through hole, the wall surfaces being shared by the one large-capacity through hole and adjacent large-capacity through holes to a total (b) of lengths in the cross section of wall surfaces of one large-capacity through hole, the wall surfaces being shared by the one large-capacity through hole and adjacent small-capacity through holes is defined as &#x3b1;. A ratio (A/B) of the area (A) of the cross section of the one large-capacity through hole to the area (B) of the cross section of one of the adjacent small-capacity through holes is defined as &#x3b2;. The &#x3b1; and &#x3b2; satisfy the relationship represented by the formulas:0&#x3c;&#x3b1;&#x2266;1.5 and 2&#x3c;&#x3b2;&#x2266;2.75, and &#x3b2;&#x2267;(20/9)&#x3b1;+.

A honeycomb structural body which is capable of increasing the limiting collection amount of particulate, reducing the pressure loss in use, and reducing fluctuations in the pressure loss even if the flow rate from an internal combustion engine of exhaust gases fluctuates. The honeycomb structural body is a columnar honeycomb structural body in which a large number of through holes are arranged side by side in the length direction with a partition wall interposed therebetween. The large number of through holes are constituted by a group of large-capacity through holes, with one end thereof sealed to make the total cross-sectional areas perpendicular to the length direction relatively greater, and a group of small-capacity through holes, with the other end thereof sealed to make the total cross-sectional areas relatively smaller. The honeycomb structural body includes a plurality of columnar porous ceramic members.

The invention is a catalyst formed by covering each surface of particles in a ceramic support with an alumina thin film and holding an active catalyst component with the surface of the thin film, which is large in the pore size and porosity and small in the pressure loss irrespectively of forming the alumina thin film on the surface and is produced, for example, by immersing the ceramic support in an aluminum-containing metallic compound, preliminarily firing, immersing in hot water, drying, firing and finally holding the active catalyst component on the alumina thin film on the surface of the support.

Catalyst and method for preparation thereof

A method of producing a catalyst carrier. The method comprises contacting a silicon-containing ceramic material with a solution of an aluminum containing metal compound, firing the resulting material, immersing the material in hot water and, again firing the material.

Catalyst carrier and method of producing same

Particulate filter for diesel engine

A catalyst carrier which comprises particles of a silicon-containing ceramic material. Each of these particles is covered by a film of alumina on which a noble metal is carried.

Growing community of inventors

Gifu, Japan

Teruo Komori