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 m, a pore diameter (median pore diameter) d50 at 50% being 18-27 m, a pore diameter d90 at 90% being 10 m or more, and (d10d90)/d50 being 2.3 or less; (ii) [=log(d20)log(d80)] being 0.25 or less, wherein 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 S.sub.n=(V.sub.nV.sub.n1)/[log(d.sub.n)log(d.sub.n1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein d.sub.n and V.sub.n are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and d.sub.n1 and V.sub.n1 are respectively a pore diameter and a cumulative pore volume at a (n1)-th measurement point.

Provided is a honeycomb fired body in which the pressure loss in the initial state where PM has not accumulated is sufficiently low, the strength is sufficiently high, and the heat capacity is not small. The honeycomb fired body of the present invention is a honeycomb fired body including a plurality of cells in each of which one end is plugged and which serve as channels of exhaust gas, and porous cell partition walls that define the cells, wherein the honeycomb fired body is formed of SiC, the plurality of cells include peripheral cells located at an outermost peripheral region of the honeycomb fired body and inner cells located more inward than the peripheral cells, all the inner cells have the same cross-sectional shape that is a rectangle in a plane perpendicular to the longitudinal direction thereof, each peripheral cell is defined by the cell partition walls and an outer wall forming a periphery of the honeycomb fired body, the cell partition walls in contact with the outer wall each have a thick wall region where the wall thickness gradually increases toward the outer wall, the cross-sectional shape of the peripheral cells in a plane perpendicular to the longitudinal direction thereof is a shape formed by reducing the rectangular cross-sectional shape of the inner cells to obtain a reduced rectangle and chamfering or rounding two corners of the reduced rectangle, the cross-sectional area of each peripheral cell in a plane perpendicular to the longitudinal direction thereof is 60 to 80% of the cross-sectional area of each inner cell in a plane perpendicular to the longitudinal direction thereof, the cell partition walls include inter-peripheral-cell cell partition walls each located between the peripheral cells and inter-inner-cell cell partition walls each located between the inner cells, and the minimum thickness of the inter-peripheral-cell cell partition walls is greater than the thickness of the inter-inner-cell cell partition walls.

A sealed honeycomb structure may include porous walls dividedly forming inlet cells and outlet cells extending from an end surface of an inlet side to an end surface of an outlet side, inlet and outlet side sealing portion 5b, and an inlet side sealing portion, wherein at least one outlet cell is a reinforced cell where a reinforcing part 6 for reinforcing the outlet cell 2b is formed at at least one corner portion 21a at which the walls on a cross-section vertical to an extending direction of the cell cross each other, wherein the inlet cell is a non-reinforced cell where the reinforcing part is not formed at all the corner portions at which the walls on the cross-section vertical to the extending direction of the cell cross each other, and wherein the reinforcing parts 6 of the reinforced cells 22 are formed at a section of the honeycomb structure from the end surface of the outlet side in the extending direction of the cell.

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 m, a pore diameter (median pore diameter) d50 at 50% being 18-27 m, a pore diameter d90 at 90% being 10 m or more, and (d10d90)/d50 being 2.3 or less; (ii) [=log(d20)log(d80)] being 0.25 or less, wherein 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 S.sub.n=(V.sub.nV.sub.n-1)/[log(d.sub.n)log(d.sub.n-1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein d.sub.n and V.sub.n are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and d.sub.n-1 and V.sub.n-1 are respectively a pore diameter and a cumulative pore volume at a (n1)-th measurement point.

The invention relates to a die (10) for the extrusion of catalyst molding, catalyst support molding, or adsorbent molding (60) in flow direction (32) of an extrudable composition from an entry side (12) to a discharge side (14) of the die comprising a shell (56) and comprising one or more channel-formers (18) which are displacers of the extrudable composition and which extend in flow direction of the extrudable composition, wherein the channel-formers (18) have been metal-printed. It is preferable that this is free from cavities for receiving extrudable composition which extend at right angles to the flow direction (32) of the extrudable composition, and that this is free from connections running at right angles from channel-formers (18) to the interior side wall (22) of the die (10). The invention further relates to a process for the production, by means of 3D metal printing, of a metal-printed die (10) for the extrusion of catalyst moldings/support moldings (60).

An extrusion die (16) including a plurality of pins (38) having side surfaces defining an intersecting array of slots (30) extending axially into the die (16) from a discharge face (34) of the die (16). A plurality of feedholes (28) extend axially from an inlet face (32) of the die (16) opposite to the discharge face (34). The feedholes (28) connect with the slots (30) at intersections (35) within the die (16) to create a flow path from the inlet face (32) to the discharge face (34). A first coating (42) is on at least a portion of the feedholes (28) in a first zone (46) extending over a first axial length of the flow path. A second coating (44) that is different than the first coating (42) is on at least a portion of the side surfaces (37) of the pins (38) in a second zone (48) extending over a second axial length of the flow path. Methods of fabricating an extrusion die (16) and manufacturing a ceramic article (100), such as a honeycomb body, are also disclosed.

A pillar-shaped honeycomb structure, comprising an outer peripheral side wall; first cells having an opening on the first end surface and having a sealing portion on the second end surface; and second cells adjacent to the first cells with partition walls interposed therebetween and having a sealing portion on the first end surface and having an opening on the second end surface; wherein the outer peripheral side wall, the partition walls, and the sealing portions are fired, and comprise cordierite as a main component and one or more sintering aids selected from ceria, zirconia, and titania; wherein in the partition walls, assuming an average porosity of a portion in a range A, and a portion in a range B is P.sub.1 (%); and assuming an average porosity of a portion in a range C is P.sub.2 (%), 4P.sub.1P.sub.27 is satisfied.

A honeycomb structure comprising a plurality of cell channels that pass through an interior of the honeycomb structure and are partitioned by partition walls, wherein the partition walls comprise a solid organic compound having an amino group, an organic binder, and an inorganic binder.