A honeycomb structure comprising a pillar-shaped honeycomb structure body having a porous partition wall disposed so as to surround a plurality of cells, wherein let that A denotes an absolute value of open frontal area (%) in a plane of the honeycomb structure body orthogonal to the extending direction of the cells and P denotes an absolute value of porosity (%) of the partition wall, the honeycomb structure has a value represented by the following expression (1) that is 0.05 to 0.12, let that D denotes an average pore diameter (m) of the partition wall and G denotes a geometric surface area (mm.sup.2/mm.sup.3) of the partition wall, the honeycomb structure has a value represented by the following expression (2) that is 8 to 50 (μm×mm.sup.2/mm.sup.3), and the honeycomb structure has a hydraulic diameter of the cells that is 1.1 mm or more,
(1−A/100)×(1−P/100),  Expression (1)
D×G.  Expression (2)

A honeycomb structure includes a pillar-shaped honeycomb structure body having a porous partition wall and a circumferential wall, wherein in a section orthogonal to the extending direction of the cells of the honeycomb structure body, the shape of the cell is a polygonal shape with a corner having an arc shape, a thickness T1[mm] of the partition wall is 0.0500 to 0.1400 mm, a radius of curvature R1[mm] of the corner having the arc shape of the cell and the thickness T1[mm] of the partition wall satisfy the relationship of Equation (1), in the section orthogonal to the extending direction of the cells of the honeycomb structure body, the outer diameter of the honeycomb structure body is 190.5 to 355.6 mm, and a porosity of the partition wall is 20 to 40%.

0.0050≤R1×T1≤0.0150  Equation (1):

A particulate filter 23 is configured by being provided with, arranged side by side, a plurality of honeycomb-shaped segments 29, 30, 31 having a plurality of cells 32. The density of cells in the segments 30, 31 disposed in the outer circumference part is set to be lower than the density of cells in the segments 29 disposed in the center part. In addition, the segments 30, 31 disposed in the outer circumference part are configured so that the density of the cells 32 becomes lower as the area of the end face becomes smaller.

A particulate filter having a honeycomb structure of a matrix of interconnected porous walls including inlet cells and outlet cells defining a plurality of inlet channels and outlet channels, respectively, wherein at least a portion of the outlet cells are larger than any of the inlet cells, and a cross-sectional shape of at least some of the outlet channels is rectangular. Honeycomb extrusion dies, honeycomb bodies, honeycomb structures, and methods of manufacture are described, as are other aspects.

A honeycomb structure, including: a pillar-shaped honeycomb structure body having a first end face and a second end face and including a porous partition wall disposed so as to surround a plurality of cells, the plurality of cells extending from the first end face to the second end face and serving as a through channel of fluid, wherein the partition wall has a porosity of 45 to 65%, the partition wall has an average pore diameter of 15 to 25 μm, and the partition wall has a cumulative pore volume, which is measured by mercury intrusion porosimetry, such that a pore volume ratio of pores having pore diameters of 10 μm or less relative to the overall pore volume of the partition wall is 10% or less, and a pore volume ratio of pores having pore diameters of 40 μm or more is 10% or less.

A honeycomb structure (110) includes intersecting porous walls (106). Inlet channels (108i) and outlet channels (108o) are formed by the intersecting porous walls (106), wherein the inlet channels (108i) comprise inlet hydraulic diameters (HDi) and the outlet channels (108o) comprise outlet hydraulic diameters (HDo). The inlet channels (108i) comprise inlet corners (220i) with inlet corner radii (Ri) and the outlet channels (108o) comprise outlet corners (2200) with outlet corner radii (Ro). A centerpost (124) is defined by adjacent opposing inlet corners (220i) of two of the inlet channels (108i) and adjacent opposing outlet corners (2200) of two of the outlet channels (108o). A first diagonal length (D1) is a shortest distance between the opposing outlet corners (220o) of the two outlet channels (108o) and a second diagonal length (D2) is a shortest distance between the opposing inlet corners (220i) of the two inlet channels (108i). The honeycomb structure (110) has certain aspect ratios D1:D2 depending on hydraulic diameter ratios HDi:HDo.

A honeycomb structure having a cellular honeycomb matrix of intersecting porous walls forming cell channels with triangular cross-sectional shapes and filleted vertices in the triangular cross-sectional shapes. The porous walls include % P≥40% and MPD>8 μm. The matrix includes a cell channel density of 150 cpsi to 600 cpsi (23.3 cpscm to 93 cpscm) and wall thicknesses of between 2 mils and 12 mils (between 51 μm to 300 μm). Honeycomb extrusion dies and methods of manufacturing the honeycomb body having triangular-shaped cell channels are provided, as are other embodiments.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein the partition wall defining inflow cells includes partition wall parts making up sides of polygon that is sectional shape of each cell, the partition wall parts each having a surface that is a face defining the inflow cell, the partition wall part is either a first partition wall part loaded with the exhaust-gas purifying catalyst on the surface so that a percentage of the area loaded therewith exceeds 10%, or a second partition wall part loaded with the exhaust-gas purifying catalyst so that a percentage of the area loaded therewith is 10% or less, and the partition wall is configured to include one or more the first partition wall parts and one or more the second partition wall parts as the partition wall parts.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion. The partition wall defining outflow cells includes an exhaust-gas purifying catalyst at least at a part of a region of 0 to 80% of a thickness of the partition wall and includes a portion that does not include the exhaust-gas purifying catalyst in a region of exceeding 80% and being 100% or less of the thickness of the partition wall, and the partition wall defining the inflow cells is not loaded with the exhaust-gas purifying catalyst on the surface, or is loaded with the exhaust-gas purifying catalyst so that a percentage of a ratio of an area of a range loaded with the exhaust-gas purifying catalyst to a surface area of the partition wall defining the inflow cells is 10% or less.

A ceramic filter having a pillar-shaped honeycomb structure, wherein when observing a plurality of pores from a surface of partition walls with a laser microscope and plotting an equivalent circle diameter (μm) of each pore on an X-axis and a pore depth (μm) of each pore on a Y-axis on a two-dimensional coordinate system, a slope of a regression line (y/x) obtained by a least squares method in a range of 20≤x≤40 is 0 to 0.20, an average value of the pore depth of the plurality of pores is 2.5 μm to 5.0 μm, and a number density of the plurality of pores is 600/mm.sup.2 to 2450/mm.sup.2.