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 filter includes a plugged honeycomb structure body which has cell rows arranged along one direction in a cross section of the honeycomb structure body and including a first cell row in which at least the inflow cells are included and in which in the cross section perpendicular to the extending direction of the cells, a through channel area SA occupied by the inflow cells is larger than a through channel area SB occupied by the outflow cells, and a second cell row in which at least the outflow cells are included. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell row and a curvature radius R (μm) of a curved shape of corner portions of a polygonal shape of each cell satisfy a relation of Equation (1) below: Equation (1): 0.4≤(R/1000)/((P1+P2)/2)×100≤20.

The honeycomb structure includes a pillar-shaped honeycomb structure body that includes a porous partition wall. When the thickness (μm) of the partition wall is defined as T.sub.1 and, among pores formed in the partition wall, the value of an average pore diameter (μm) of specific pores whose pore diameters measured by a mercury press-in method are 20 to 100 μm is defined as D.sub.(20 to 100), T.sub.1/D.sub.(20 to 100) that is a value obtained by dividing T.sub.1 by D.sub.(20 to 100) is not less than 2.4, a ratio of a pore volume of the specific pores to an overall pore volume of the partition wall is 5 to 45%, and a ratio of a pore volume of large pores whose pore diameters are not less than 100 μm to the overall pore volume of the partition wall is not more than 5%.

A honeycomb structure, including: a plurality of pillar shaped honeycomb segments, each of the pillar shaped honeycomb segments including a partition wall and a plugged portion; and a joining layer arranged so as to join side surfaces of the pillar shaped honeycomb segments to each other. The honeycomb structure satisfies the following equations (1) to (3):

y≤1000  (1);

y≤717.92x.sup.−0.095  (2); and

y≥462.4x.sup.−0.153  (3),

in which y is a maximum temperature (° C.) at which the use of the honeycomb structure is accepted, and x is a thermal conduction factor represented by the following equation:

thermal conduction factor=(thermal conductivity of the partition wall×thermal conductivity of the joining layer)/(average thickness of the joining layer×porosity of the partition wall).

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 honeycomb structure body has cell walls, inner cells and outer cells, and a boundary partition wall. The inner cells are arranged in a high cell density area and the outer cells are arranged in a low cell density area. A cell density of the high cell density area is higher than a cell density of the low cell density area. Cell reinforced parts are formed at a first intersection part at which the cell walls intersect each other. Boundary reinforced parts are formed at a second intersection part at which the cell walls and the boundary partition wall intersect each other. The honeycomb structure body satisfies a relationship of Sb>Sc, where Sb indicates an average value of a cross sectional area of the overall boundary reinforced parts, and Si indicates an average value of a cross sectional area of the overall inner cell reinforced parts.

An inorganic membrane filtration article and methods for making the same. The membrane filtration article includes a sintered flow-through ceramic honeycomb with a plurality of partition walls defining a plurality of open channels from an inlet end of the honeycomb to an outlet end of the honeycomb. The honeycomb is formed from a cordierite composition with low-sodium and/or low-potassium content for enhanced filtration performance.

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 having porous partition walls provided, surrounding a plurality of cells which serve as fluid through channels extending from an inflow end face to an outflow end face, and porous plugging portions provided either at the ends on the inflow end face side or the outflow end face side of the cells, wherein the plugging portions are composed of a porous material, the honeycomb structure has a central region and a circumferential region, and a ratio of an area of the circumferential region with respect to that of the central region ranges from 0.1 to 0.5, porosity of a central plugging portion in the central region, is higher than that of a circumferential plugging portion in the circumferential region, and the porosity of the central plugging portion ranges from 76% to 85%, and that of the circumferential plugging portion from 60% to 75%.

A honeycomb filter comprising a pillar-shaped honeycomb structure having a porous partition wall disposed so as to surround a plurality of cells which serve as a fluid through channel extending from an inflow end face to an outflow end face and a porous plugging portion provided at either an end on the inflow end face side or an end on the outflow end face side of the cell, wherein in a processed image obtained by binarizing an electron microscope image of a visual field area of 480 m640 m of the plugging portion, the plugging portion is composed of a plurality of particles, and the number of the particles having an area of 0.25 m.sup.2 or more is 1000 or more and 3500 or less.