Abstract: There is provide a honeycomb filter which can suppress generation of cracks in plugged portions due to heat generated by burning of a PM during regeneration and comprises a honeycomb basal body including porous partition walls arranged to form a plurality of cells disposed in parallel with one another and including inflow cells and outflow cells which are formed adjacent to the inflow cells; first plugged portions with which one end of each of the inflow cells is plugged; second plugged portions with which another end of each of the outflow cells is plugged; porous collecting layers formed on the inflow-cells side surfaces of the partition walls; and end aggregate layers made of a particulate aggregate material and formed on the inflow-cells-side surfaces of the first plugged portions, and a thickness of the end aggregate layers is from 0.5 to 5 mm.

Abstract: Provided is a honeycomb structure in which as compared with partition walls of an end face side portion of all inlet of a fluid, partition walls of an end face side portion of an outlet of the fluid satisfy at least one of conditions of (1) a heat conductivity being relatively high, (2) a heat capacity being relatively large, (3) a bending strength being relatively high and (4) a porosity being relatively low. In this honeycomb structure, the melting or thermal shock breakdown of the partition walls does not easily occur, and the structure is suitably used as a DPF.

Abstract: A honeycomb structure 1 includes: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure 3 where a plurality of honeycomb segments 11 are bonded by means of a bonding layer 12 at an outer wall 10 of each of them, and an outer peripheral coat layer 9 disposed on an outer peripheral face 8 of the periphery-ground article; wherein at least one of the bonding layer 12 and the outer peripheral coat layer 9 is formed by the use of honeycomb-forming slurry containing: biologically soluble fibers containing a metal oxide capable of extricating a metal ion, an inorganic binder containing a colloidal oxide having silica sol, and a chelate compound capable of multi-coordinating with the metal ion or an additive containing a first buffer solution or acid.

Abstract: A honeycomb structure includes: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure 3 where honeycomb segments 11 are bonded by a bonding layer 12 at an outer wall 10 of each of them, and an outer peripheral coat layer 9 disposed on an outer peripheral face 8 of the periphery-ground article; wherein at least one of the bonding layer 12 and the outer peripheral coat layer 9 is formed using honeycomb-forming slurry containing biologically soluble fibers containing a metal oxide capable of extricating a metal ion and an inorganic binder containing a colloidal oxide having modified silica sol manufactured by adding a substance containing amine or an aqueous solution of a water-soluble metalate of an amphoteric metal to silica sol. Crack generation of the outer peripheral coat layer and/or deterioration of bonding strength of the bonding layer can be inhibited.

Abstract: A honeycomb structure whose shape is composed of plural honeycomb segments being bonded integrally by means of a bonding material; the honeycomb structure having inner partition walls with plural first pores and defining respective cells serving as flow channels for exhaust gas, outer circumferential wall having second pores, and surrounding the inner partition walls, and inner partition walls having third pores and contacting with a processed outer circumferential surface becoming an outermost circumference through processing of an outer circumferential portion. A filling composition for the second pores and a filling composition for the third pores having the specified functions respectively are also provided.

Abstract: There is disclosed a honeycomb structure having a plurality of segments and each including a plurality of cells, wherein each segment has a porous base material having the honeycomb shape, and a modified portion formed by impregnating a part of the base material with a slurry including particles smaller than the average pore diameter of the base material, followed by a heat treatment, the base material has a porosity of 30 to 80% and an average pore diameter of 5 to 40 ?m, and the modified portion is partially formed on the section of the segment vertical (orthogonal) to the axial direction of the cells, and has a porosity which is 2 to 20% lower than that of the base material and an average pore diameter which is 0.1 to 10 ?m smaller than that of the base material.

Abstract: There is provided a honeycomb structure where a catalyst is loaded on surfaces of inner pores of the surface layer and on a surface of the surface layer; a relation between a catalyst area proportion A of the catalyst to a gap area proportion B of a gap in a cross-section of the surface layer on the inlet side is 1%<A/B<90%; and a relation between an average catalyst area proportion, A1, from the surface to a point having a depth of one third of the thickness of the surface layer including the surface of the surface layer on the inlet side and a catalyst area proportion A2 in a central portion of the surface layer is A1/A2>1.5.

Abstract: There is provide a honeycomb filter which can suppress generation of cracks in plugged portions due to heat generated by burning of a PM during regeneration and comprises a honeycomb basal body including porous partition walls arranged to form a plurality of cells disposed in parallel with one another and including inflow cells and outflow cells which are formed adjacent to the inflow cells; first plugged portions with which one end of each of the inflow cells is plugged; second plugged portions with which another end of each of the outflow cells is plugged; porous collecting layers formed on the inflow-cells side surfaces of the partition walls; and end aggregate layers made of a particulate aggregate material and formed on the inflow-cells-side surfaces of the first plugged portions, and a thickness of the end aggregate layers is from 0.5 to 5 mm.

Abstract: A silicon carbide-based porous article comprising silicon carbide particles as an aggregate, metallic silicon and an aggregate derived from siliceous inorganic particles to form pores through volume shrinkage by heat treatment, wherein the porosity is 45 to 70%, and the average pore diameter is 10 to 20 ?m is provided. Also provided is a method for producing a silicon carbide-based porous article, comprising; adding inorganic particles to form pores through volume shrinkage by heat treatment to a raw-material mixture containing silicon carbide particles and metallic silicon, then forming into an intended shape, calcinating and firing the resultant green body, forming pores through volume shrinkage of the inorganic particles by heat treatment, and the shrunk inorganic particles being present as an aggregate in the porous article.

Abstract: Provided are a silicon carbide-based porous article comprising silicon carbide particles as an aggregate, metallic silicon and an aggregate derived from organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment; and a method for producing the silicon carbide-based porous article, comprising, adding organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment to a raw-material mixture containing silicon carbide particles and metallic silicon, then forming into an intended shape, calcinating and/or firing the resultant green body, forming pores through volume shrinkage due to decomposition/conversion of the organometallic compound particles, and the decomposed/converted substance of the organometallic compound particles being present as an aggregate in the porous article.

Abstract: There is provided a honeycomb structure where a catalyst is loaded on surfaces of inner pores of the surface layer and on a surface of the surface layer; a relation between a catalyst area proportion A of the catalyst to a gap area proportion B of a gap in a cross-section of the surface layer on the inlet side is 1%<A/B<90%; and a relation between an average catalyst area proportion, A1, from the surface to a point having a depth of one third of the thickness of the surface layer including the surface of the surface layer on the inlet side and a catalyst area proportion A2 in a central portion of the surface layer is A1/A2>1.5.

Abstract: There is disclosed a honeycomb structure having a plurality of segments and each including a plurality of cells, wherein each segment has a porous base material having the honeycomb shape, and a modified portion formed by impregnating a part of the base material with a slurry including particles smaller than the average pore diameter of the base material, followed by a heat treatment, the base material has a porosity of 30 to 80% and an average pore diameter of 5 to 40 ?m, and the modified portion is partially formed on the section of the segment vertical to the axial direction of the cells, and has a porosity which is 2 to 20% lower than that of the base material and an average pore diameter which is 0.1 to 10 ?m smaller than that of the base material.

Abstract: A honeycomb structure 1 includes: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure 3 where a plurality of honeycomb segments 11 are bonded by means of a bonding layer 12 at an outer wall 10 of each of them, and an outer peripheral coat layer 9 disposed on an outer peripheral face 8 of the periphery-ground article; wherein at least one of the bonding layer 12 and the outer peripheral coat layer 9 is formed by the use of honeycomb-forming slurry containing: biologically soluble fibers containing a metal oxide capable of extricating a metal ion, an inorganic binder containing a colloidal oxide having silica sol, and a chelate compound capable of multi-coordinating with the metal ion or an additive containing a first buffer solution or acid.

Abstract: A honeycomb structure includes: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure 3 where honeycomb segments 11 are bonded by a bonding layer 12 at an outer wall 10 of each of them, and an outer peripheral coat layer 9 disposed on an outer peripheral face 8 of the periphery-ground article; wherein at least one of the bonding layer 12 and the outer peripheral coat layer 9 is formed using honeycomb-forming slurry containing biologically soluble fibers containing a metal oxide capable of extricating a metal ion and an inorganic binder containing a colloidal oxide having modified silica sol manufactured by adding a substance containing amine or an aqueous solution of a water-soluble metalate of an amphoteric metal to silica sol. Crack generation of the outer peripheral coat layer and/or deterioration of bonding strength of the bonding layer can be inhibited.

Abstract: There is provided a method for producing a honeycomb segment bonded article, the method inhibiting decrease in strength properties due to a variance in a texture of the bonding material layer between a plurality of honeycomb segments unitarily bonded together by means of the bonding material layer formed of the bonding material. After producing a preliminary block by unitarily bonding a plurality of honeycomb segments having a plurality of cells being partitioned by partition walls and passing through in the axial direction with a bonding material at a bonding face of each of the honeycomb segments and drying the honeycomb segments, the preliminary blocks are integrally bonded together, or honeycomb segments of one layer are bonded on an outer peripheral face of the preliminary block.

Abstract: Provided is a honeycomb structure in which as compared with partition walls of an end face side portion of all inlet of a fluid, partition walls of an end face side portion of an outlet of the fluid satisfy at least one of conditions of (1) a heat conductivity being relatively high, (2) a heat capacity being relatively large, (3) a bending strength being relatively high and (4) a porosity being relatively low. In this honeycomb structure, the melting or thermal shock breakdown of the partition walls does not easily occur, and the structure is suitably used as a DPF.

Abstract: A silicon carbide-based porous article comprising silicon carbide particles as an aggregate, metallic silicon and an aggregate derived from siliceous inorganic particles to form pores through volume shrinkage by heat treatment, wherein the porosity is 45 to 70%, and the average pore diameter is 10 to 20 ?m is provided. Also provided is a method for producing a silicon carbide-based porous article, comprising; adding inorganic particles to form pores through volume shrinkage by heat treatment to a raw-material mixture containing silicon carbide particles and metallic silicon, then forming into an intended shape, calcinating and firing the resultant green body, forming pores through volume shrinkage of the inorganic particles by heat treatment, and the shrunk inorganic particles being present as an aggregate in the porous article.

Abstract: A honeycomb structure which effectively prevents generation of defects such as cracks by thermal stress during use and regeneration and has excellent durability is provided.

Abstract: Provided are a silicon carbide-based porous article comprising silicon carbide particles as an aggregate, metallic silicon and an aggregate derived from organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment; and a method for producing the silicon carbide-based porous article, comprising, adding organometallic compound particles to form pores through volume shrinkage due to decomposition/conversion by heat treatment to a raw-material mixture containing silicon carbide particles and metallic silicon, then forming into an intended shape, calcinating and/or firing the resultant green body, forming pores through volume shrinkage due to decomposition/conversion of the organometallic compound particles, and the decomposed/converted substance of the organometallic compound particles being present as an aggregate in the porous article.

Abstract: A system for exhaust gas purification includes at least one adsorbent capable of adsorbing harmful substances such as hydrocarbons and the like in exhaust gas and at least one catalyst containing a catalyst component, capable of reducing said harmful substances, both provided at an in-line position of exhaust pipe of internal combustion engine. In the system, the hydrocarbons, etc. in the exhaust gas emitted during cold engine start up of internal combustion engine are adsorbed by the adsorbent and the adsorbed hydrocarbons, etc. are desorbed from the adsorbent with the temperature rise of the adsorbent caused by the heat of the exhaust gas and are burnt on the catalyst. The adsorbent contains a H type ?-zeolite having a SiO2/Al2O3 ratio of 100 or more and can maintain good adsorption capability even when exposed to an exhaust gas of 750° C. or more form an internal combustion engine.