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.

An exhaust gas purification filter includes a cell assembly including cells and a partition wall, seal members, and a skin member. The partition wall has a porosity of 50% to 70%. The skin member has a thickness T of 0.3 mm to 1.0 mm. The partition wall includes crossing portions, each cell has at least one part of an outer periphery defined by a corresponding one of the crossing portions, the at least one part of the outer periphery is rounded to have a value of radius of curvature R being 0.02 mm to 0.6 mm A degree of distortion δ being a degree of change in the external dimensions of the filter in axial direction, is greater than 0 and is 1.5 mm or less. A value of a structural variable X, expressed by Equation 1 below, is 0.05 to 6, X=T×R/δ . . . Equation 1.

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 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 is composed of a material containing cordierite as a main component thereof, porosity of the partition wall measured by a mercury press-in method is 60 to 68%, an average pore diameter of the partition wall measured by a mercury press-in method is 8 to 12 and in a pore diameter distribution which indicates a cumulative pore volume of the partition wall measured by a mercury press-in method, with a pore diameter (μm) on an abscissa axis and a log differential pore volume (cm.sup.3/g) on an ordinate axis, a first peak that includes a maximum value of the log differential pore volume has a pore diameter value of 10 μm or less, the pore diameter value corresponding to a ⅓ value width of the maximum value.

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 is composed of a material containing cordierite as a main component thereof, porosity of the partition wall measured by a mercury press-in method is 60 to 68%, an average pore diameter of the partition wall measured by a mercury press-in method is 13 to 18 μm, and in a pore diameter distribution indicating a cumulative pore volume of the partition wall measured by a mercury press-in method, with a pore diameter (μm) on an abscissa axis and a log differential pore volume (cm.sup.3/g) on an ordinate axis, a first peak including a maximum value of the log differential pore volume has a pore diameter value of 15 μm or less, the pore diameter value corresponding to a ⅓ value width of the maximum value.

An exhaust gas purification filter includes a honeycomb structure part and sealing parts. The honeycomb structure part has a porous partition wall and a plurality of cells defined by the partition wall to form exhaust gas flow paths. The sealing parts seal alternately a gas inflow-side end face or a gas outflow-side end face of the cells. The exhaust gas purification filter includes fine pores with diameters of 10 μm or less measured by the mercury intrusion method that account for 5% or more of all pores by volume in the honeycomb structure part. The partition wall has a plurality of communication pores communicating between the cells adjacent to the partition wall and has constricted communication pore of which a largest diameter Φ.sub.1 and a smallest diameter Φ.sub.2 satisfy relationships Φ.sub.1≥50, 100×Φ.sub.2/Φ.sub.1≤20.

A cordierite-containing ceramic body with % P≥50%, df≤0.50, and a combined weight percentage of crystalline phases containing cordierite and indialite of at least 85 wt %. The porous ceramic body contains, as expressed on a relative oxide weight percent basis in terms of MgO, Al.sub.2O.sub.3, and SiO.sub.2 that is within a field defined by (15.4, 34.1, and 50.5), (12.2, 34.1, and 53.7), (13.3, 31.2, and 55.5), and (16.6, 31.1, and 52.3). Batch composition mixtures and methods of manufacturing a porous ceramic body using the batch compositions are provided, as are other aspects.

A plugged honeycomb structure, including: a pillar-shaped honeycomb structure body including porous partition walls; and plugging portions disposed at open ends of cells at an inflow end face side or at an outflow end face side, wherein a pore diameter corresponding to the cumulative pore volume of 10% is D10, a pore diameter corresponding to the cumulative pore volume of 30% is D30, a pore diameter corresponding to the cumulative pore volume of 50% is D50, a pore diameter corresponding to the cumulative pore volume of 70% is D70, a pore diameter corresponding to the cumulative pore volume of 90% is D90, the pore diameter D10 is 6 μm or more, the pore diameter D90 is 58 μm or less, and the plugged honeycomb structure satisfies the relationship of Expression (1).
0.35≤(D70−D30)/D50≤1.5  Expression (1):

A honeycomb body having intersecting porous walls which includes first through fourth cells, wherein the cells extend from inlet to outlet face and are plugged to define a repeating structural unit with three inlets and one outlet channel. Repeating structural unit includes a first channel including length L.sub.1, width W.sub.2, and area A.sub.1, a second channel including length L.sub.2, the width W.sub.2, and area A.sub.2, a third channel including the length L.sub.1, width W.sub.1, and area A.sub.3, and a fourth channel including the length L.sub.2, the width W.sub.1, and A.sub.4, wherein the first through third channels are inlets and the fourth channel is a rectangular outlet and at least one of W.sub.1≥W.sub.2 and L.sub.1≠L.sub.2, i.e. W.sub.1≥W.sub.2, or L.sub.1≠L.sub.2, or W.sub.1≥W.sub.2 and L.sub.1≠L.sub.2. Repeating structural unit has a quadrilateral outer perimeter. Particulate filters including the honeycomb body, honeycomb extrusion dies, and methods of manufacturing the honeycomb body are provided.

A coated ceramic honeycomb body comprising a honeycomb structure comprising a matrix of intersecting porous walls forming a plurality of axially-extending channels, at least some of the plurality of axially-extending channels being plugged to form inlet channels and outlet channels, wherein a total surface area of the outlet channels is greater than a total surface area of the inlet channels, and wherein a catalyst is preferentially located within the outlet channels, and preferentially disposed on non-filtration walls of the outlet channels. Methods and apparatus configured to preferentially apply a catalyst-containing slurry to the outlet channels and non-filtration walls are provided, as are other aspects.