Abstract: A honeycomb structure is disclosed that includes plural honeycomb units bonded together by using a sealing material layer, each of the honeycomb units including plural through-holes separated by plural partition walls and provided in parallel along a longitudinal direction of the honeycomb units, wherein a surface roughness Ra of an outer surface of the honeycomb structure is greater than or equal to about 1 ?m and less than or equal to about 50 ?m, each of the honeycomb units includes at least ceramic particles, and inorganic fibers and/or whisker, and an area of a cross section of one of the honeycomb units perpendicular to the longitudinal direction of the one of the honeycomb units is greater than or equal to about 5 cm2 and less than or equal to about 50 cm2.

Abstract: A method of manufacturing a porous sintered body includes mixing first silicon carbide particles, second silicon carbide particles, and a pore forming material having an average particle diameter Y ?m to obtain a molding material. The first silicon carbide particles have an average particle diameter X ?m larger than an average particle diameter of the second silicon carbide particles. Relationships 15?X, 0.5·X?Z?0.9·X, and 0.8·Z?Y?1.8·Z are satisfied, wherein Z ?m is an average pore diameter of the porous sintered body no less than 10 ?m and no greater than 20 ?m. The molding material is molded into a molded body. The molded body is degreased to eliminate the pore forming material from the molded body.

Abstract: The present invention provides a method for producing a honeycomb structure which carries a catalyst component containing at least one element selected from the group consisting of alkali metals and alkaline earth metals and purifies exhaust emissions.

Abstract: The invention provides a method for producing a porous body comprising: a starting material mixing step of mixing ceramic particles serving as an aggregate and a sintering aid which includes at least one element selected from the group consisting of rare earth elements, alkaline earth elements, Al and Si such that the amount of the sintering aid is about 1.0% by weight or less relative to the total amount of the ceramic particles and the sintering aid to form a puddle; and a molding and firing step of molding the puddle into a molded body and firing the molded body.

Abstract: A honeycomb structure 10 of the present invention comprises: porous honeycomb units 11 having multiple through-holes, including the first form of an inorganic material (for example, ceramic particles), the second form of an inorganic material (for example, inorganic fibers or ceramic particles having large particle sizes), and an inorganic binder; and sealing material layers 14 jointing the porous honeycomb units 11 at outer surfaces 13 where the through-holes are not open. The cross-sectional area perpendicular to the through-holes is about 5 to about 50 cm2. The ratio of the total cross-sectional area of the porous honeycomb units 11 to the cross-sectional area of the honeycomb structure 10 is not less than about 85%. The honeycomb structure 10 reduces thermal stress or vibration applied to each porous honeycomb unit 11, by the sealing material layers 14, and allows for a more effective use of surface on which catalyst components are dispersed.

Abstract: A honeycomb structural body includes a columnar honeycomb structural body having large-capacity through holes and small-capacity through holes extending in parallel in a length direction of the columnar structural body. The large-capacity through holes and the small-capacity through holes have a polygonal shape in a cross section perpendicular to the length direction, and the large-capacity through holes and the small-capacity through holes have R-chamfered corner portions or C-chamfered corner portions in the cross section perpendicular to the length direction.

Abstract: A honeycomb structure includes aluminum titanate and cell walls. The cell walls extend along a longitudinal direction of the honeycomb structure to form a plurality of cells between the cell walls. A porosity of the honeycomb structure is from about 40% to about 60%. In a binary image of substrate portions and pore portions of each of the cell walls, an area ratio (%) of the pore portions to a whole area in a rectangularly-divided image is in a range from (the porosity?about 25%) to (the porosity+about 25%). The binary image is converted from a microscopic image of a cross section of each of the cell walls in parallel with the longitudinal direction. The rectangularly-divided image is formed by dividing the binary image in a direction parallel to a thickness direction of each of the cell walls at a predetermined width.

Abstract: A honeycomb structure includes cells and aluminum titanate. The cells are provided substantially in parallel with one another in a longitudinal direction of the honeycomb structure. The cells are each sealed at either one end. The aluminum titanate includes about 40% to about 60% by mass of Al2O3, about 30% to about 50% by mass of TiO2, and about 1% to about 15% by mass of (MgO+SiO2). The honeycomb structure has a porosity of about 40% to about 60% and an aperture ratio of about 55% to about 75%.

Abstract: A ceramic honeycomb structural body is manufactured by molding silicon carbide raw powders into a honeycomb pillar shape and then firing it to form a sintered body. The silicon carbide raw powders are comprised of about 60 to about 80% by mass of particles of first particle group having one frequency peak in the particle size distribution and a particle size of 1.0 ?m to about 100 ?m, and about 20 to about 40% by mass of particles of a second particle group having a particle size of about 0.1 ?m or more and less than 1.0 ?m.

Abstract: A honeycomb structure 20 is provided with multiple honeycomb units 10 having multiple through holes 12 arranged in parallel along the longitudinal direction, and a seal layer 26 for joining the units 10 via the outer faces 13 on which the through holes 12 are not opened. The honeycomb structure satisfies the expression 2?A/B?0.0002×C+5 (about 28000?C), where A (g/cm3) represents a product of the apparent density of the honeycomb unit 10 and volume ratio of the honeycomb unit 10 to the whole honeycomb structure, B (g/cm3) represents a product of the apparent density of the seal layer 26 and volume ratio of the seal layer 26 to the whole honeycomb structure, and C (m2/L) represents a specific surface area per unit volume of the honeycomb structure 20.

Abstract: A honeycomb structure having multiple through holes includes at least ceramic particles and an inorganic binder. A wall thickness of each wall between adjoining through holes, on which a catalyst component is carried, is designed to be not greater than about 0.25 mm. The honeycomb structure satisfies a relation of Y?250×X+22500 (50?X?80), where X denotes an aperture ratio (%) of a honeycombed face of the honeycomb structure perpendicular to the multiple through holes and Y denotes a specific surface area per unit volume (m2/L) of the honeycomb structure.

Abstract: A honeycomb structure includes aluminum titanate, cell walls, and pore portions. The cell walls extend along a longitudinal direction of the honeycomb structure to define cells between the cell walls. The pore portions have an average pore diameter of about 10 ?m to about 20 ?m. A length of a longest pore portion among the pore portions in a binary image including substrate portions and the pore portions is about 8 times or less of the average pore diameter. The binary image is converted from a microscopic image of a cross section of the cell walls in parallel with the longitudinal direction. The length is measured along a line drawn in a direction perpendicular to a thickness direction of the cell walls.

Abstract: A pillar-shaped honeycomb structured body comprises large-capacity through holes and small-capacity through holes, a first partition wall between two adjacent large-capacity through holes, a second partition wall between a large-capacity through holes and a small-capacity through holes adjacent to each other. Each of the plurality of large-capacity through holes and small-capacity through holes extends from a first end face to a second end face. An aperture rate ? (%) is a ratio between the sum of the area of the large-capacity through holes at the second end face and the area of the second end face. The difference in the thickness of the first partition wall and the second partition wall is ? (mm). The relationship between ? and ? satisfies the following inequalities (1) and (2): 0.0022?+0.0329???0.0071?+0.2553 (1), and about 35???about 60(2).

Abstract: A method for manufacturing a honeycomb structure includes molding a wet mixture containing an aluminum titanate powdery material to form a honeycomb molded body. The aluminum titanate powdery material contains about 40% to about 60% by mass of Al2O3, about 30% to about 50% by mass of TiO2, and about 1% to about 15% by mass of (MgO+SiO2). The honeycomb molded body has cells provided substantially in parallel with one another in a longitudinal direction of the honeycomb molded body. The honeycomb molded body is fired at a temperature of about 1200° C. to about 1700° C.

Abstract: A honeycomb filter includes an outer wall having a substantially cylindrical shape and a central axis of the substantially cylindrical shape, first walls provided at an inner side of the outer wall and extending along the central axis, and second walls provided at the inner side of the outer wall and extending along the central axis. The first walls and the second walls substantially perpendicularly cross to define cells having a substantially square shape in a cross-section perpendicular to the central axis. A thickness of the outer wall in the cross-section at a first intersection between the outer wall and a first diameter substantially parallel to the first walls in the cross-section and a thickness of the outer wall in the cross-section at a second intersection between the outer wall and a second diameter substantially parallel to the second walls in the cross-section are largest.

Abstract: An object of the present invention is to provide a honeycomb structural body (filter) which has a low pressure loss upon collecting particulates, makes it possible to deposit a great amount of particulates and ashes, and is less likely to produce cracks.

Abstract: A honeycomb structure comprises a porous ceramic which is composed of several cells aligned across a cell wall longitudinally. The cell has either one end sealed. The gas permeability coefficient k of the cell wall is between about 0.5 ?m2 and about 1.5 ?m2.

Abstract: A honeycomb structured body of the present invention is a honeycomb structured body in which a plurality of porous ceramic members are combined with one another through an adhesive layer, each of the porous ceramic members having a plurality of cells which are allowed to penetrate in a longitudinal direction with a wall portion therebetween and either one end of which is sealed, with a catalyst supporting layer being adhered to the wall portion, wherein, supposing that the rate of the pore volume of pores having a pore diameter of 10 ?m or less to the entire pore volume of the porous ceramic member is X1 (%), the porosity is Y1 (%) and the weight of the catalyst supporting layer is Z1 (g/l), these X1, Y1 and Z1 are allowed to satisfy the following expressions (1) and (2): X1?20?Z1/10??(1), and Y1?35+7Z1/40??(2) (where about 20?Z1?about 150).

Abstract: It is to provide a ceramic sintered body and a ceramic filter having a long-term stability which can prevent cracks from occurring due to the breakage of ceramic particles when thermal stress is applied in regeneration process and the like, and can prevent catalyst carried from deteriorating when regeneration treatment is conducted repeatedly. The invention is a ceramic sintered body comprising ceramic coarse particles and porous bonding layers existing between the ceramic coarse particles to connect the particles and comprising ceramic fine particles having an average particle size smaller than that of the ceramic coarse particles and/or the aggregates thereof, and a ceramic filter prepared by using the ceramic sintered body.

Abstract: A honeycomb structure includes at least one honeycomb unit. The at least one honeycomb unit has a longitudinal direction and includes an inorganic binder, a cell wall, and xeolite. The cell wall extends from a first end face to a second end face of the at least one honeycomb unit along the longitudinal direction to define cells. The at least one honeycomb unit includes the zeolite in an amount exceeding approximately 250 g/L per apparent volume. The xeolite is present at a first concentration at a center part of a thickness of the cell wall and at a second concentration at a surface of the cell wall. The second concentration is larger than the first concentration.