A pillar shaped honeycomb structure including pillar shaped honeycomb segments joined together via joining material layers, wherein each of the pillar shaped honeycomb segment includes: an outer peripheral wall; and a porous partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the plurality of cells extending from one end face to other end face to form a flow path, wherein a joining material forming the joining material layers includes magnetic particles, and wherein the joining material contains aggregates, and at least a part of the aggregates comprises the magnetic particles.

A pillar shaped honeycomb structure includes: an outer peripheral wall; and a porous partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the plurality of cells extending from one end face to the other end face to form a flow path. The partition wall is a porous body containing aggregates and binding materials binding the aggregates. At least a part of the aggregates includes magnetic particles.

A honeycomb structure includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells, wherein a major component of the partition wall is cordierite, a porosity of the partition wall is 45 to 55%, an average pore diameter of the partition wall is 8 to 19 μm, a cumulative pore volume of the partition wall is such that a pore volume ratio of the pores having a pore diameter larger than a thickness of the partition wall relative to an overall pore volume of the partition wall is 3.0% or less, and a pore volume ratio of the pores having a pore diameter of 10 μm or less relative to the overall pore volume of the partition wall is 30% or more, and a pore diameter distribution of the partition wall is a unimodal distribution, or a multimodal distribution.

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 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 method for manufacturing a pillar-shaped honeycomb structure filter including preparing a pillar-shaped honeycomb structure having a plurality of first cells and a plurality of second cells that are alternately arranged adjacent to each other with a porous partition wall interposed therebetween; adhering ceramic particles containing 50% by mass or more in total of one or two selected from SiC and SiN to a surface of the first cells; and performing a heat-oxidation treatment on the pillar-shaped honeycomb structure in which the ceramic particles are adhered to the surface of the first cells to form a porous film comprised of the ceramic particles having an oxide film thereon so as to satisfy: (1) 0.05≤T≤0.5; (2) 0.05≤T/D50; and (3) 4≤{(W.sub.1−W.sub.0)/W.sub.0×100}/D50.

Catalyzed particulate filters comprise three-way conversion (TWC) catalytic material that permeates walls of a particulate filter such that the catalyzed particulate filter has a coated porosity that is less than an uncoated porosity of the particulate filter. The coated porosity is linearly proportional to a washcoat loading of the TWC catalytic material. A coated backpressure is non-detrimental to performance of the engine. Such catalyzed particulate filters may be used in an emission treatment system downstream of a gasoline direct injection engine for treatment of an exhaust stream comprising hydrocarbons, carbon monoxide, nitrogen oxides, and particulates.

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.

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.