Patent ID: 8143190

Claim:
A honeycomb structure comprising: a plurality of segments having a honeycomb shape and each including a plurality of cells as through channels of a fluid which are defined by porous partition walls between the inlet-side end surface of the structure as the inlet side of the fluid and the outlet-side end surface of the structure as the outlet side of the fluid, the plurality of segments being assembled and integrally joined in a direction vertical to the axial direction of the cells, wherein each segment comprises 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 μm, and the modified portion is partially formed on the section of the segment 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 μm smaller than that of the base material.