EP0254557A2
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EP
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A porous structure and a process for production thereof
Assignee: Denso Corp
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Filing: 1987-07-22
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Granted: —
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Expires: 2007-07-22
Abstract
Abstract A porous ceramic structure and an organic foam structure are disclosed having a cell structure with a three-dimensional network skeleton having internal communicating spaces, in which individual cells of said cell structure constituting said structure have a long and thin shape and the ratio of average major axis b to average minor axis a, b/a, of said cell is at least 1.5. A porous ceramic structure may be obtained by adhering a ceramic slurry to the surface of the skeleton of a long, thin resin foam stretched 120% or more and which is air-permeable and is burnt down by combustion, sintering said slurry into a ceramic layer at a high temperature, and simultaneously burning down the skeleton of said resin foam. In one embodiment, a porous ceramic structure is made up so that the ratio of average major axis b to average minor axis a, b/a, of said cell is larger in the peripheral portion of section of said structure than in its central portion. The disclosed structures are suitable for use in filters for collecting particulates contained in exhaust gas from diesel engines, in carriers for purifying exhaust gas by removing harmful gas components such as hydrocarbons, carbon monoxide, nitrogen oxides, etc. in exhaust gas, or in filters for purifying air.
Inventors
- 👤 Hitoshi Yoshida
- 👤 Yukihisa Takeuchi
- 👤 Naoto Miwa
- 👤 Kazuyuki Ito
- 👤 Naoki Ueda
- 👤 Yasunao Miura
- 👤 Yasuhide Okamoto
- 👤 Hiroshi Kondo
- 👤 Tomio Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 18:15
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/02; F01N3/021; F01N3/0218; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; C; C04; C04B; C04B38/00; C04B38/0051; C04B38/06; C04B38/0615; F01N3/022; F01N3/0222; F01N2330/00; F01N2330/06; F02; F02B; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
58 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, in which the individual cells of said cell structure constituting said structure have a long and thin shape and the ratio b/a of the average major axis b to the average minor axis a of said cell is at least 1.5.
Claim 2
Dependent Claim
58 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, in which the individual cells of said cell structure constituting said structure have a long and thin shape and the ratio b/a of the average major axis b to the average minor axis a of said cell is at least 1.5.
Claim 3
Dependent Claim
42 words
A porous ceramic structure according to Claim 1, wherein the average minor axis of said cell is 0.5 to 2 mm and said ratio b/a of said average major axis b to said average minor axis a, is from 1.5 to 6.
Claim 4
Dependent Claim
42 words
A porous ceramic structure according to Claim 2, which is used as a particulates-collecting filter for a diesel engine by placing in exhaust gas so that the minor axis of said cell is substantially parallel to the flow direction of exhaust gas.
Claim 5
Dependent Claim
62 words
A porous ceramic structure according to Claim 2, wherein a catalytic substance is coated on the surface of said three-dimensional network skeleton, and the porous ceramic structure is used as a catalytic material for purifying exhaust gas from engines, by placing in exaust gas so that the major axis of said cell is substantially parallel to the flow direction of exhaust gas.
Claim 6
Dependent Claim
33 words
A porous ceramic structure according to any one of the preceding claims, which is obtained by adhering and sintering said ceramic slurry in excess to at least a part of said porous ceramic.
Claim 7
Dependent Claim
86 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, obtained by adhering a ceramic slurry to the surface of skeleton of a resin foam which is air-permeable and which can be burnt down by combustion, sintering said slurry into a ceramic layer at a high temperature, and simultaneously burning down the skeleton of said resin foam, said resin foam being a stretched resin foam of long and thin shape having a degree of stretching of 120% or more.
Claim 8
Dependent Claim
86 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, obtained by adhering a ceramic slurry to the surface of skeleton of a resin foam which is air-permeable and which can be burnt down by combustion, sintering said slurry into a ceramic layer at a high temperature, and simultaneously burning down the skeleton of said resin foam, said resin foam being a stretched resin foam of long and thin shape having a degree of stretching of 120% or more.
Claim 9
Dependent Claim
24 words
A porous ceramic structure according to Claim 6, wherein the average cell diameter of said resin foam before stretching is 0.5 to 7 mm.
Claim 10
Dependent Claim
44 words
A porous ceramic structure according to Claim 6 or 7, which is used as a particulates-collecting filter for a diesel engine by placing in exhaust gas so that the major axis of said cell is substantially perpendicular to the flow direction of exhaust gas.
Claim 11
Dependent Claim
63 words
A porous ceramic structure according to Claim 6 or 7, wherein a catalytic substance is coated on the surface of said three-dimensional network skeleton and the porous ceramic structure is used as a carrier for purifying exhaust gas from engines, by placing in exhaust gas so that the major axis of said cell is substantially parallel to the flow direction of exhaust gas.
Claim 12
Dependent Claim
75 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, wherein individual cells of said cell structure have a long and thin shape, and the porous ceramic structure is made up so that the ratio b/a of the average major axis b to the average minor axis a, of said cell is larger in a peripheral portion of the section of said structure than in a central portion.
Claim 13
Dependent Claim
75 words
A porous ceramic structure having a cell structure with a three-dimensional network skeleton having internal communicating spaces, wherein individual cells of said cell structure have a long and thin shape, and the porous ceramic structure is made up so that the ratio b/a of the average major axis b to the average minor axis a, of said cell is larger in a peripheral portion of the section of said structure than in a central portion.
Claim 14
Dependent Claim
30 words
A porous ceramic structure according to Claim 10, wherein the ratio b/a of the average major axis b to the average minor axis of said cell is at least 1.5.
Claim 15
Dependent Claim
57 words
A porous organic structure having a cell structure with a three-dimensional network skelton having internal communicating spaces, wherein individual cells of said cell structure constituting said organic foam have a long and thin shape, and the ratio b/a of the average major axis b to the average minor axis a of said cell is at least 1.5.
Claim 16
Dependent Claim
57 words
A porous organic structure having a cell structure with a three-dimensional network skelton having internal communicating spaces, wherein individual cells of said cell structure constituting said organic foam have a long and thin shape, and the ratio b/a of the average major axis b to the average minor axis a of said cell is at least 1.5.
Claim 17
Dependent Claim
82 words
A process for producing a porous ceramic structure which comprises the steps of: stretching an air-permeable resin foam in one direction with a degree of stretching of 120% or more to obtain a stretched resin foam having a long and thin cell shape, adhering a ceramic slurry to the surface of skeleton of said stretched resin foam, and firing said stretched resin foam to sinter said ceramic slurry into a ceramic layer and burn down the skeleton of said stretched resin foam.
Claim 18
Dependent Claim
82 words
A process for producing a porous ceramic structure which comprises the steps of: stretching an air-permeable resin foam in one direction with a degree of stretching of 120% or more to obtain a stretched resin foam having a long and thin cell shape, adhering a ceramic slurry to the surface of skeleton of said stretched resin foam, and firing said stretched resin foam to sinter said ceramic slurry into a ceramic layer and burn down the skeleton of said stretched resin foam.
Claim 19
Dependent Claim
22 words
A process for producing a porous ceramic structure according to Claim 13, wherein said degree of stretching is from 120 to 220%.
Claim 20
Dependent Claim
97 words
A process for producing a ceramic structure, which comprises forming a resin foam into a plate, stretching the plate of resin foam in one direction, laminating the stretched resin foam plate to form a matrix having a three-dimensional network skeleton, adhering a ceramic slurry to the surface of the matrix, sintering said ceramic slurry and simultaneously burning down the skeleton of said matrix, and thereby imparting, to cells constituting the ceramic structure, a long and thin shape having a ratio of the average major axis b to the average minor axis a, b/a, of at least 1.5.
Claim 21
Dependent Claim
97 words
A process for producing a ceramic structure, which comprises forming a resin foam into a plate, stretching the plate of resin foam in one direction, laminating the stretched resin foam plate to form a matrix having a three-dimensional network skeleton, adhering a ceramic slurry to the surface of the matrix, sintering said ceramic slurry and simultaneously burning down the skeleton of said matrix, and thereby imparting, to cells constituting the ceramic structure, a long and thin shape having a ratio of the average major axis b to the average minor axis a, b/a, of at least 1.5.
Claim 22
Dependent Claim
27 words
A process for producing a ceramic structure according to Claim 15, wherein said matrix is obtained by rolling said plate of resin foam to laminate the same.
Claim 23
Dependent Claim
30 words
A process for producing a ceramic structure according to Claim 15, wherein said matrix is obtained by placing said plates of resin foam one upon another to laminate the same.
References Cited (Backward Citations)
No citation records indexed.
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