A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein a thickness of the partition wall is 0.217 mm or less, a porosity of the partition wall is 57 to 63%, an average pore diameter of the partition wall is 6 to 14 μm, a number per unit area of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 800 to 1500 /mm.sup.2, an average equivalent circle opening diameter of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 6.7 to 12.5 μm, and in a pore diameter distribution of the partition wall, D10 is 3.0 to 7.0 μm, D90 is 13.0 to 27.0 μm, and (Log (D90)-Log (D10))/Log (D50) is 0.75 or less.

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 particulate trap filter body has asymmetrical channels. The cross-sectional shape of the asymmetrical channel structure includes a combination of hexagonal, square and triangular shapes. The hexagonal channel and the triangular channel act as inlet channel, and the square channel acts as outlet channel. Compared with the traditional symmetrical filter body structure, the inlet channel volume and filter body wall area can be effectively increased by more than 30%, which means that with capturing the same amount of particles, the particle cake layer formed on the wall surface is thinner. The limiting carbon load of the new channel structure is increased by more than 30%, having a very positive effect on reducing the regeneration frequency and prolonging the service life of the trap.

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.

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.

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 comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein a thickness of the partition wall is 0.257 mm or less, a porosity of the partition wall is 52 to 57%, an average pore diameter of the partition wall is 6 to 13 .Math.m, a number per unit area of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 .Math.m is 800 to 1500 /mm.sup.2, an average equivalent circle opening diameter of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 .Math.m is 8.0 to 12.0 .Math.m, and in a pore diameter distribution of the partition wall, D10 is 2.0 to 5.5 .Math.m, D90 is 13.0 to 25.5 .Math.m, and (Log(D90)-Log(D10))/Log(D50) is 0.84 or less.

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein, in a pore diameter distribution of the partition wall, in the case where the pore diameter (.Math.m) whose cumulative pore volume is 10% of the total pore volume is denoted by D10, the pore diameter (.Math.m) whose cumulative pore volume is 50% of the total pore volume is denoted by D50, and the pore diameter (.Math.m) whose cumulative pore volume is 90% of the total pore volume is denoted by D90, all of the following equations (1) to (6) are satisfied.

[00001]$\begin{array}{cc}\text{8}\text{.4}\mu \text{}\text{m<D10}& \text{­­­(1)}\end{array}$

[00002]$\begin{array}{cc}\text{17}\text{.5}\mu \text{}\text{m<D50<24}\text{.0}\mu \text{}\text{m}& \text{­­­(2)}\end{array}$

[00003]$\begin{array}{cc}\text{D90<55}\text{.2}\mu \text{}\text{m}& \text{­­­(3)}\end{array}$

[00004]$\begin{array}{cc}\left(\text{logD90-logD10}\right)/\text{logD50}\text{<0}\text{.60}& \text{­­­(4)}\end{array}$

[00005]$\begin{array}{cc}\text{logD90}/\text{logD50}\text{<1}\text{.30}& \text{­­­(5)}\end{array}$

[00006]$\begin{array}{cc}\text{logD50}/\text{logD10}\text{<1}\text{.38}& \text{­­­(6)}\end{array}$

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein, in a pore diameter distribution of the partition wall, in the case where the pore diameter (.Math.m) whose cumulative pore volume is 10% of the total pore volume is denoted by D10, the pore diameter (.Math.m) whose cumulative pore volume is 50% of the total pore volume is denoted by D50, and the pore diameter (.Math.m) whose cumulative pore volume is 90% of the total pore volume is denoted by D90, all of the following equations (1) to (6) are satisfied.

[00001]$\begin{array}{cc}3.9\mu \text{}\text{m<D10}& \text{­­­(1)}\end{array}$

[00002]$\begin{array}{cc}10.5\mu \text{}\text{m<D50<16}\text{.6}\mu \text{}\text{m}& \text{­­­(2)}\end{array}$

[00003]$\begin{array}{cc}\text{D90<38}\text{.7}\mu \text{}\text{m}& \text{­­­(3)}\end{array}$

[00004]$\begin{array}{cc}\left(\log \text{}\text{D90-logD10}\right)/\log \text{}\text{D50<0}\text{.80}& \text{­­­(4)}\end{array}$

[00005]$\begin{array}{cc}\log \text{}\text{D90}/\text{logD50<1}\text{.36}& \text{­­­(5)}\end{array}$

[00006]$\begin{array}{cc}\log \text{}\text{D50}/\text{logD10<1}\text{.56}& \text{­­­(6)}\end{array}$

A honeycomb filter includes a honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion disposed at one end of the cells, wherein the plurality of cells are arranged in a square grid pattern along a first direction and a second direction in a section orthogonal to an extending direction of the cells, the shape in the section is a deformed square having a specific corner, the specific corner includes a first curved portion, a second curved portion, and a connecting portion, a radius of curvature R1 of the first curved portion and a radius of curvature R2 of the second curved portion are 40 to 80 μm, respectively, and a center distance between a center of curvature O1 of the first curved portion and a center of curvature O2 of the second curved portion is 80 to 200 μm.