US 2016/0250577 A1 · CORDIERITE-TYPE CERAMIC HONEYCOMB STRUCTURE AND ITS PRODUCTION METHOD

Abstract

A cordierite-type ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls; the cell walls having (a) porosity of more than 65% and 75% or less, (b) in a pore diameter distribution measured by mercury porosimetry, (i) a pore diameter d10 at a cumulative pore volume corresponding to 10% of the total pore volume being less than 50 μm, a pore diameter (median pore diameter) d50 at 50% being 18-27 μm, a pore diameter d90 at 90% being 10 μm or more, and (d10−d90)/d50 being 2.3 or less; (ii) σ[=log(d20)−log(d80)] being 0.25 or less, wherein σ represents the difference between a logarithm of a pore diameter d20 at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of a pore diameter d80 at a cumulative pore volume corresponding to 80% of the total pore volume; and (iii) the maximum of the inclination Sn=−(Vn−Vn-1)/[log(dn)−log(dn-1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein dn and Vn are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and dn-1 and Vn-1 are respectively a pore diameter and a cumulative pore volume at a (n−1)-th measurement point.

Claims8

Dependent claims

A cordierite-type ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls,

(a) said cell walls having porosity of more than 65% and 75% or less;
and
(b) in a pore diameter distribution measured by mercury porosimetry,
(i) a pore diameter d10 at a cumulative pore volume (cumulative volume of pores in a range from the maximum pore diameter to a particular pore diameter) corresponding to 10% of the total pore volume being less than 50 μm,
a pore diameter (median pore diameter) d50 at 50% being 18 μm or more and 27 μm or less,
a pore diameter d90 at 90% being 10 μm or more, and
(d10−d90)/d50 being 2.3 or less;
(ii) σ[=log(d20)−log(d80)] being 0.25 or less, wherein σ represents the difference between a logarithm of a pore diameter d20 at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of a pore diameter d80 at a cumulative pore volume corresponding to 80% of the total pore volume;
and
(iii) the maximum of the inclination Sn=−(Vn−Vn-1)/[log(dn)−log(dn-1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein dn and Vn are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and dn-1 and Vn-1 are respectively a pore diameter and a cumulative pore volume at a (n−1)-th measurement point.

7 more elements

A method for producing a cordierite-type ceramic honeycomb structure comprising the steps of extruding a moldable material comprising a ceramic material and a pore-forming material constituted by hollow resin particles coated with inorganic powder to form a predetermined green body, and drying and sintering said green body;

said moldable material comprising 8-16% by mass of said pore-forming material per 100% by mass of said ceramic material;
said pore-forming material having a median diameter D50 of 25-35 μm, a particle diameter D10 (at a cumulative volume corresponding to 10% of the total volume) of 14-24 μm, and a particle diameter D90 (at a cumulative volume corresponding to 90% of the total volume) of 45-60 μm, in a curve expressing the relation of a particle diameter to a cumulative volume (cumulative volume of particles having diameters equal to or smaller than a particular particle diameter), a particle diameter distribution deviation SD [=log(D80)−log(D20)] being 0.4 or less, wherein D20 is a particle diameter at a cumulative volume corresponding to 20% of the total volume, and D80 is a particle diameter at a cumulative volume corresponding to 80% of the total volume, D20<D80;
and
said pore-forming material having the maximum compression recovery Lmax of 3.0 mm or more, and a compression recovery L in a compression stress range of 2-6 MPa, which is 80% or more of said maximum compression recovery Lmax, the compression recovery L being defined by the returning distance (mm) of a piston having an outer diameter of 8 mm applying a predetermined compression stress to 0.3 g of a pore-forming material in a metal cylinder having an inner diameter of 8 mm and a depth of 100 mm, when the pore-forming material is relieved of the compression stress, and the maximum compression recovery Lmax being the maximum of the compression recovery L.

1 more element

Dependencies are inferred from the claim text.

Cordierite-type ceramic honeycomb structure and its production method

Life of this patent

Cordierite-type ceramic honeycomb structure and its production method

Life of this patent

Abstract

Claims8