The disclosure generally relates to filters, methods, and systems for filtering particulates from the exhaust of internal combustion engines such as gasoline direct injection engines and methods of preparing particulate filters.

A honeycomb structure having a cellular honeycomb matrix of intersecting porous walls forming cell channels with triangular cross-sectional shapes and filleted vertices in the triangular cross-sectional shapes. The porous walls include % P≥40% and MPD>8 μm. The matrix includes a cell channel density of 150 cpsi to 600 cpsi (23.3 cpscm to 93 cpscm) and wall thicknesses of between 2 mils and 12 mils (between 51 μm to 300 μm). Honeycomb extrusion dies and methods of manufacturing the honeycomb body having triangular-shaped cell channels are provided, as are other embodiments.

Provided is a honeycomb filter, including: a pillar-shaped honeycomb substrate having an inflow end face and an outflow end face and including a porous partition wall surrounding a plurality of cells; and a plugging portion disposed at any one of ends of the cells at the inflow end face and at the outflow end face. In a cross section orthogonal to an extending direction of the cells, inflow cells have a pentagonal or a hexagonal shape, and outflow cells have a square shape. The cells are configured that the inflow cells surround one outflow cell and one side of an inflow cell and one side of an adjacent outflow cell are parallel to each other. The partition wall is configured that thickness of a first partition wall disposed between the inflow cells and the outflow cells is larger than thickness of a second partition wall disposed between the inflow cells.

A ceramic porous body includes skeleton portions; and pore portions formed between the skeleton portions, the pore portions being capable of allowing a fluid to flow therethrough. In a cross section parallel to a flow direction of the fluid, the skeleton portions have a ratio of a skeleton length of 40 μm or more of 15% or less in a direction orthogonal to the flow direction of the fluid.

A honeycomb filter including: a honeycomb structure having a porous partition wall provided surrounding a plurality of cells; and a plugging portion disposed to seal either one end portion on the inflow or the outflow end face side of the cells, wherein the cell in which the plugging portion is provided at the outflow end face side and the inflow end face side is open is defined as an inflow cell, the cell the plugging portion is provided at the inflow end face side and the outflow end face side is open is defined as an outflow cell, the honeycomb structure further has a trapping layer for the particulate matter on an inner surface side of the partition wall, the trapping layer includes a portion composed of a sintered body of CeO.sub.2 particles on at least a surface layer, and the average particle diameter is 1.1 μm or less.

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.

A pillar-shaped honeycomb structure filter including a plurality of first cells and a plurality of second cells, the first cells and the second cells being alternately arranged adjacent to each other with a porous partition wall interposed therebetween, wherein a ceramic porous film, in which an average film thickness T (unit: μm) is 2 to 50 μm, a porosity P (unit: %) is 65 to 90%, and the average film thickness T and the porosity P satisfy a relational expression of 0.36T+60≤P≤0.75T+72, is formed on a surface of each of the first cells.

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.

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)

An exhaust gas purification catalyst device includes a honeycomb base material and an inlet-side coat layer, wherein: the honeycomb base material includes a plurality of cells partitioned by porous partition walls, the plurality of cells including inlet-side cells and outlet-side cells and being configured such that exhaust gas that has flowed into the inlet-side cells passes through the partition walls and is exhausted from the outlet-side cells; and the inlet-side coat layer is present on the surface sides of the partition walls of the inlet-side cells, with the proportion of 4-9 μm through-pores in the through-pore diameter distribution of the partition walls being at least 80 vol %, and the peak pore diameter measured using a mercury porosimeter being at least 3.0 μm greater than the peak through-pore diameter measured using a perm porometer.