US Patent 7658985 Honeycomb structure

A honeycomb structure useful as exhaust gas trapping filter, particularly, as a diesel particulate filter (DPF) for trapping particulate matter, etc. in diesel engine exhaust gas and capable of effectively inhibiting defects such as cracks due to thermal stress, by reducing influence of thermal stress generated upon use or regeneration. The honeycomb structure includes: an integrally joined body constituted of plural honeycomb segments at joint faces with a bonding material layer, and an outer peripheral coat layer. Thickness of the bonding material layer satisfies the relation: (T2)=(1.2 to 10.0)×(T1) between an average thickness (T1) at positions (X1) and (X2) located at the both ends in the central axis direction of segments and a maximum thickness (T2) between positions (Y1) and (Y2) apart from respective ends in 3 to 40% of the whole length of the honeycomb segment.