Abstract: A honeycomb structure prevents catalyst slurry from leaching out when applying a wash coat for making a catalyst supported, ensuring air permeability of the outer portion and in which there is no occurrence of cracking when used as a gasoline particulate filter. The honeycomb structure having: a honeycomb substrate composed of porous partition walls forming a plurality of cells and a porous outer portion; and a resin composition on the outer portion of the honeycomb substrate, wherein the outer portion and the partition walls of the honeycomb substrate are formed of the same material; a porosity of the honeycomb structure is 50% or more; and the resin composition is impregnated into pores of the whole outer portion; and the impregnation depth is equal to the outer portion thickness or a part of the resin composition is impregnated deeper than the outer portion and reaches the cell partition walls.

Abstract: Provided is a method of producing a film-coated cylindrical honeycomb structure formed with a coating liquid on an outer portion of a cylindrical honeycomb structure including partition walls and the outer portion, the partition walls forming a plurality of cells, the outer portion serving as a circumferential side. In the method, the cylindrical honeycomb structure is mounted between at least two rollers such that the circumferential side of the cylindrical honeycomb structure contacts with circumferential sides of the rollers, the coating liquid supplied from an application part is deposited on the cylindrical honeycomb structure while being rotated, and then the deposited coating liquid is dried or cured to form the film on the outer portion.

Abstract: A honeycomb structure prevents catalyst slurry from leaching out when applying a wash coat for making a catalyst supported, ensuring air permeability of the outer portion and in which there is no occurrence of cracking when used as a gasoline particulate filter. The honeycomb structure having: a honeycomb substrate composed of porous partition walls forming a plurality of cells and a porous outer portion; and a resin composition on the outer portion of the honeycomb substrate, wherein the outer portion and the partition walls of the honeycomb substrate are formed of the same material; a porosity of the honeycomb structure is 50% or more; and the resin composition is impregnated into pores of the whole outer portion; and the impregnation depth is equal to the outer portion thickness or a part of the resin composition is impregnated deeper than the outer portion and reaches the cell partition walls.