Patent ID: 8110274

Claim:
A honeycomb structure aggregate, comprising: a plurality of the honeycomb structures bonded together by a sealing material layer, wherein: each of the honeycomb structures comprises a plurality of through-holes separated by a separation wall and provided in parallel along a longitudinal direction thereof, all of the through-holes being open on both end faces of the honeycomb structure; each of the honeycomb structures further comprises ceramic particles and an inorganic fiber and/or a whisker; an area of a cross section of each of the honeycomb structures being perpendicular to a perforating direction of the through-holes is 5 cm 2 or more and 50 cm 2 or less; a thickness of the separation wall is about 0.25 mm or less; a length of each of the through-holes is about 50-fold or greater and about 350-fold or less of a hydraulic diameter of each of the through-holes; and an open area ratio (X) % of a cross section of each of the honeycomb structures perpendicular to the through-holes and a surface area per unit volume (Y (m 2 /L)) of the separation wall for each of the through-holes satisfy: Y≧ 250 (m 2 /(L×%))× X +22500 (m 2 /L) (about 50 ≦X ≦about 85), and wherein the surface area per unit volume (Y) is less than or equal to about 70,000 m 2 /L.