Abstract: 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 ?m or more, the pore diameter D90 is 58 ?m or less, and the plugged honeycomb structure satisfies the relationship of Expression (1). 0.35?(D70?D30)/D50?1.

Abstract: The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows: 1.5?T?16×(100?P)?1.4; and??Equation (1): 20?P?75??Equation (2).

Abstract: A honeycomb structure includes a pillar-shaped honeycomb structure body which includes a porous partition wall 1 defining a plurality of cells, and a part of the plurality of cells is an inflow cell of which a portion at the inflow end face side is opened and a portion at the outflow end face side is provided with a plugging portion, the residual cell of the plurality of cells is an outflow cell of which a portion at the inflow end face side is provided with the plugging portion and a portion at the outflow end face side is opened, the inflow cell and the outflow cell are arranged adjacent to each other, and a value of a ratio between a bending strength of a first specimen cut out according to condition (1) and a bending strength of a second specimen cut out according to condition (2) is 1.1 to 2.0.

Abstract: 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 ?m or more, the pore diameter D90 is 58 ?m or less, and the plugged honeycomb structure satisfies the relationship of Expression (1). 0.35?(D70?D30)/D50?1.

Abstract: A honeycomb filter, wherein when a thermal expansion coefficient at 300 to 600° C. of a material constituting a honeycomb substrate is indicated by A (×10?6/° C.), the four-point bending strength of the material constituting the honeycomb substrate is indicated by B (MPa), the thickness of a thinnest portion in a portion partitioning outlet plugging cells of a partition wall 1 is indicated by t (mm), the thickness of a portion partitioning an outlet plugging cell and an inlet plugging cell of the partition wall is indicated by WT (mm), and the distance between the center of the outlet plugging cell and the center of the inlet plugging cell adjacent to each other is indicated by CP (mm), a relation of the following equation (1) is satisfied. 0.714×WT+0.160?t/CP?0.163×A/B+0.

Abstract: The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows: 1.5?T?16×(100?P)?1.4; and??Equation (1): 20?P?75.

Abstract: A honeycomb filter, wherein when a thermal expansion coefficient at 300 to 600° C. of a material constituting a honeycomb substrate is indicated by A (×10?6/° C.), the four-point bending strength of the material constituting the honeycomb substrate is indicated by B (MPa), the thickness of a thinnest portion in a portion partitioning outlet plugging cells of a partition wall 1 is indicated by t (mm), the thickness of a portion partitioning an outlet plugging cell and an inlet plugging cell of the partition wall is indicated by WT (mm), and the distance between the center of the outlet plugging cell and the center of the inlet plugging cell adjacent to each other is indicated by CP (mm), a relation of the following equation (1) is satisfied. 0.714×WT+0.160?t/CP?0.163×A/B+0.

Abstract: A honeycomb structure includes a pillar-shaped honeycomb structure body which includes a porous partition wall 1 defining a plurality of cells, and a part of the plurality of cells is an inflow cell of which a portion at the inflow end face side is opened and a portion at the outflow end face side is provided with a plugging portion, the residual cell of the plurality of cells is an outflow cell of which a portion at the inflow end face side is provided with the plugging portion and a portion at the outflow end face side is opened, the inflow cell and the outflow cell are arranged adjacent to each other, and a value of a ratio between a bending strength of a first specimen cut out according to condition (1) and a bending strength of a second specimen cut out according to condition (2) is 1.1 to 2.0.

Abstract: The honeycomb catalyst body includes a honeycomb structure having porous partition walls, outflow side plugged portions, inflow side plugged portions, and catalyst layers formed on the surfaces of the partition walls on the side of the outflow cells, the cells are formed so that an open area of each outflow cell is larger than an open area of each inflow cell, a porosity of the partition walls of the honeycomb structure is from 25 to 55%, and in a cross section parallel to the extending direction of the cells, a total area of the catalyst layers formed on the surfaces of the pores in the partition walls is 5% or less of a total area of the pores in the partition walls.

Abstract: The honeycomb catalyst body includes a honeycomb structure having porous partition walls, outflow side plugged portions, inflow side plugged portions, and catalyst layers formed on the surfaces of the partition walls on the side of the outflow cells, the cells are formed so that an open area of each outflow cell is larger than an open area of each inflow cell, a porosity of the partition walls of the honeycomb structure is from 25 to 55%, and in a cross section parallel to the extending direction of the cells, a total area of the catalyst layers formed on the surfaces of the pores in the partition walls is 5% or less of a total area of the pores in the partition walls.

Abstract: A honeycomb structure 20 includes a cell structure 10 having a plurality of cells 9 communicating between two open ends being partitioned and defined by porous partition walls 7, an outer wall 30 disposed at the periphery of the cell structure 10, and first plugging portions 25 disposed in a checkered flag pattern at one end and the other end of the cell structure 10 by plugging alternately either of the two open ends of the cells, a fluid to be flown from one of the open ends of each of the cells 9 being capable of penetrating the porous partition walls 7 and flowing out from the other open end 5 of each of the cells 9 as a filtered fluid. The honeycomb structure 20 includes the first plugging portions 25 having been fired after plugging, and second plugging portions 26 having been unfired even after plugging.

Abstract: In a honeycomb filter in which a plurality of cells are formed by porous partition walls, and a predetermined cell whose one end portion is plugged, and a remaining cell whose other end portion is plugged are alternately arranged in such a manner as to form checked patterns in the opposite end portions. In a section of the filter, a sectional area of the predetermined cell is different from that of the remaining cell, a value of a ratio of a channel hydraulic diameter of the cell having a large sectional area to that of the cell having a small sectional area is 1.2 or more, at least a sectional shape of the cell having the large sectional area is a quadrangular shape whose portion corresponding to at least one corner portion is circular, and a value of a ratio of minimum thickness of a portion (intersection portion) in which the partition walls cross one another to a thickness of each partition wall 2 is 0.7 or more and less than 1.3.

Abstract: A honeycomb filter 1 includes a cylindrical honeycomb structure 2 having a plurality of cells 4, and plugging members 7 disposed to alternately plug openings 5 of predetermined cells 4a on the side of one end face 6a and the openings 5 of the remaining cells 4b on the side of the other end face 6b of the structure 2 in checkered flag form, and further having second plugging members 8 disposed to plug openings 5 of cells 4 which are not plugged by the first plugging member 7 on either side of two end faces 6a and 6b of the structure 2 corresponding to 0.2 to 2.5% of the area of the cross section perpendicular to the center axis of the structure 2 in a center section occupying at least ? of the area from the center axis of the structure 2 to an outer circumferential surface 11.

Abstract: A honeycomb structure comprising porous partition walls disposed so as to form a plurality of cells extending in an axial direction. In the honeycomb structure, defining that a porosity and pore diameter of the partition walls in a central portion is (Pi) and (Di), a porosity and pore diameter of the partition walls in an outer peripheral portion is (Po) and (Do), (Pi) and (Po) have a relation of (Pi<Po); or (Pi) and (Po) have a relation of (Pi>Po) and (Di) and (Do) have a relation of (Di<Do).

Abstract: There is disclosed a honeycomb structure usable as a filter for trapping/collecting particulates included in an exhaust gas; and the structure can remove ashes deposited inside without requiring any special mechanism or apparatus or without being detached from the exhaust system. The structure includes: a plurality of through channels 9 extending to the axial direction of the honeycomb structure, porous partition walls 7 separating through channels one another, and plugging portions 11 plugging predetermined through channels 9a at one end and the rest of through channels 9b at other end opposite to the plugged end of the predetermined through channels, wherein a through-hole is formed in at least a part of the plugging portion, and its diameter is 0.2 mm or more, but not more than a value which is smaller between 1 mm and 75% of a diameter of an inscribed circle of the through channel.

Abstract: A honeycomb structure 20 includes a cell structure 10 having a plurality of cells 9 communicating between two open ends being partitioned and defined by porous partition walls 7, an outer wall 30 disposed at the periphery of the cell structure 10, and first plugging portions 25 disposed in a checkered flag pattern at one end and the other end of the cell structure 10 by plugging alternately either of the two open ends of the cells, a fluid to be flown from one of the open ends of each of the cells 9 being capable of penetrating the porous partition walls 7 and flowing out from the other open end 5 of each of the cells 9 as a filtered fluid. The honeycomb structure 20 includes the first plugging portions 25 having been fired after plugging, and second plugging portions 26 having been unfired even after plugging.

Abstract: In a honeycomb filter in which a plurality of cells are formed by porous partition walls, and a predetermined cell whose one end portion is plugged, and a remaining cell whose other end portion is plugged are alternately arranged in such a manner as to form checked patterns in the opposite end portions. In a section of the filter, a sectional area of the predetermined cell is different from that of the remaining cell, a value of a ratio of a channel hydraulic diameter of the cell having a large sectional area to that of the cell having a small sectional area is 1.2 or more, at least a sectional shape of the cell having the large sectional area is a quadrangular shape whose portion corresponding to at least one corner portion is circular, and a value of a ratio of minimum thickness of a portion (intersection portion) in which the partition walls cross one another to a thickness of each partition wall 2 is 0.7 or more and less than 1.3.

Abstract: A honeycomb filter 1 includes a cylindrical honeycomb structure 2 having a plurality of cells 4, and plugging members 7 disposed to alternately plug openings 5 of predetermined cells 4a on the side of one end face 6a and the openings 5 of the remaining cells 4b on the side of the other end face 6b of the structure 2 in checkered flag form, and further having second plugging members 8 disposed to plug openings 5 of cells 4 which are not plugged by the first plugging member 7 on either side of two end faces 6a and 6b of the structure 2 corresponding to 0.2 to 2.5% of the area of the cross section perpendicular to the center axis of the structure 2 in a center section occupying at least ? of the area from the center axis of the structure 2 to an outer circumferential surface 11.

Abstract: A honeycomb structure comprising porous partition walls disposed so as to form a plurality of cells extending in an axial direction. In the honeycomb structure, defining that a porosity and pore diameter of the partition walls in a central portion is (Pi) and (Di), a porosity and pore diameter of the partition walls in an outer peripheral portion is (Po) and (Do), (Pi) and (Po) have a relation of (Pi<Po); or (Pi) and (Po) have a relation of (Pi>Po) and (Di) and (Do) have a relation of (Di<Do).

Abstract: There is disclosed a honeycomb structure usable as a filter for trapping/collecting particulates included in an exhaust gas; and the structure can remove ashes deposited inside without requiring any special mechanism or apparatus or without being detached from the exhaust system. The structure includes: a plurality of through channels 9 extending to the axial direction of the honeycomb structure, porous partition walls 7 separating through channels one another, and plugging portions 11 plugging predetermined through channels 9a at one end and the rest of through channels 9b at other end opposite to the plugged end of the predetermined through channels, wherein a through-hole is formed in at least a part of the plugging portion, and its diameter is 0.2 mm or more, but not more than a value which is smaller between 1 mm and 75% of a diameter of an inscribed circle of the through channel.