Patent ID: 8309199

Claim:
A honeycomb structure comprising a plurality of columnar honeycomb segments in which two kinds of plural through-holes different in end face area are formed side by side by being surrounded by partition walls, each honeycomb segment having, at one end face, an inlet side of high opening ratio wherein through-holes of smaller end face area are plugged and, at other end face, an outlet side of low opening ratio wherein through-holes of larger end face area are plugged, the plurality of honeycomb segments being bonded to each other via a bonding material in the longitudinal direction of each honeycomb segment, in which honeycomb structure the bonded width of the bonding material is larger at the inlet side end face of the honeycomb structure than at the outlet side end face, wherein, in the following formula (1), 0<α<0.7 and 0.3<W Out <2.5 mm are satisfied: W In =α×{(1 −OFA In )/(1 −OFA Out )}+ W Out (1) where W In is a bonded width at inlet side, W Out is a bonded width at outlet side, OFA In is an opening ratio at inlet side, and OFA Out is an opening ratio at outlet side.