The present invention provides an exhaust purification filter with which pressure loss can be reduced, the filter having high exhaust purification performance and granular-substance-filtering performance. The exhaust purification filter comprises a filter base material having a wall flow structure, and an exhaust purification catalyst supported on a dividing wall of the filter base material, the exhaust purification filter being such that: a median pore diameter (D50) of the filter base material according to a volumetric basis is 15 μm or greater; and the exhaust purification catalyst is unevenly supported on a high-density layer, in which the density of the exhaust purification catalyst is relatively high, and a low-density layer, in which the density of the exhaust purification catalyst is relatively low.

A substrate (11) of an exhaust gas purification catalyst (10) includes inflow-side cells (21), outflow-side cells (22), and porous partition walls (23) each separating the inflow-side cell and the outflow-side cell. Catalyst portions (14, 15) are provided on surfaces of the partition walls that each face the inflow-side cell and/or surfaces of the partition walls that each face the outflow-side cell. In a cross section vertical to an exhaust gas flow direction, the percentage of the total area of voids, each void satisfying the expression L/{2(πS).sup.1/2}≤1.1, wherein L is the perimeter of the void in the cross section and S is the area of the void in the cross section, is from 3 to 10% based on the apparent area of the catalyst portion present on the partition wall.

A ceramic honeycomb structure having a web structure including a plurality of intersecting channel walls forming channels. The ceramic honeycomb structure has a total porosity greater than or equal to about 55%, an average channel wall thickness less than or equal to about 150 μm, a median pore diameter greater than or equal to about 10 μm, a d.sub.f less than or equal to about 0.45, where d.sub.f=(d.sub.50−d.sub.10)/d.sub.50, and a strength (MOR/CFA) greater than or equal to about 900 psi. A method of manufacturing a ceramic honeycomb structure by mixing a ceramic precursor batch composition having a median particle diameter less than or equal to about 10 μm and at least one starch-based pore former having a median particle diameter greater than or equal to about 10 μm. The method also includes forming a mixture of ceramic precursor batch composition and a starch-based pore former into a green ceramic structure having a web structure, and firing the green ceramic structure to yield a ceramic honeycomb structure.

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.

The present disclosure relates to porous ceramic materials and porous ceramic articles, including honeycomb structure bodies and porous ceramic filters comprised of plugged honeycomb bodies. In various embodiments, a particulate filter is disclosed herein, such as suitable as a gasoline particulate filter (GPF) for use with a gasoline engine and treating its exhaust, and/or such as a diesel particulate filter (DPF) suitable for use with a diesel engine and treating its exhaust.

A honeycomb structure prevents catalyst slurry from leaching out when applying a wash coat for making a catalyst supported, ensuring air permeability of the outer portion and in which there is no occurrence of cracking when used as a gasoline particulate filter. The honeycomb structure having: a honeycomb substrate composed of porous partition walls forming a plurality of cells and a porous outer portion; and a resin composition on the outer portion of the honeycomb substrate, wherein the outer portion and the partition walls of the honeycomb substrate are formed of the same material; a porosity of the honeycomb structure is 50% or more; and the resin composition is impregnated into pores of the whole outer portion; and the impregnation depth is equal to the outer portion thickness or a part of the resin composition is impregnated deeper than the outer portion and reaches the cell partition walls.

Provided is an exhaust gas purifying filter used with a HC purifying catalyst supported thereon. Numerous pores are formed in partitions of the exhaust gas purifying filter. In a cross-section of the partition, pores are open at a passage surface, having an open end of which the opening diameter is 50 μm or larger. In the cross-section of the partitions, the partitions include a narrow part where a pore diameter is 5 μm or more and the pore diameter becomes a minimum in a region. In the cross-section of the partitions, the region is positioned between a pair of virtual lines L.sub.1 and L.sub.2 extending from opposing sides of the opening end to a passage surface positioned opposite to the opening end along the wall thickness direction X, Z. The pore diameter at the narrow part is 6% or more and less than or equal to 20% of the opening diameter.

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.

A honeycomb body comprises a matrix of intersecting porous walls forming channels. Plugs are disposed in a percentage of the channels having the second hydraulic diameter, wherein the percentage of the channels of the second diameter having a plug is less than or equal to 15%. In some embodiments, some of the channels have a first hydraulic diameter and others have a second hydraulic diameter that is smaller than the first hydraulic diameter, and may be unplugged for plugged. The porous walls can further comprise a transverse thickness of the walls Tw less than or equal to 0.20 mm, a channel density CD greater than or equal to 62 channels per cm.sup.2, an average bulk porosity % P greater than or equal to 50%, and a median pore diameter d.sub.50 ranging from between 4.0 μm and 30.0 μm.