Patent ID: 8192826

Claim:
A hexagonal cell honeycomb structure body for use as a catalyst support capable of supporting catalysts capable of purifying an exhaust gas, comprising: a plurality of cell walls, each having a hexagonal lattice shape; a plurality of hexagonal shaped cells, each of which is surrounded by six cell walls; and a cylindrical skin layer with which the outer periphery of the hexagonal cell honeycomb structure body is covered, wherein an average thickness of each of the six basic cell walls is not more than 140 μm, where the six basic cell walls without including the cylindrical skin layer form a substantially-perfect hexagonal shaped cell, and a relationship Dax/P≧0.13 . . . (1) is satisfied, where P is a cell pitch P, and Dax is an average diameter of diameters of inscribed circles, and each of the inscribed circles is inscribed in a boundary part of opening parts of three cells at a junction area between adjacent three basic cell walls, and each of both surfaces of the basic cell wall is curved inside to form a concave shape, and an inside angle part between the adjacent two basic cell walls has a straight shape or a curved shape so that the surfaces of the adjacent two basic cell walls are smoothly connected together, wherein the surface of the basic cell wall has a rounded surface of a circular arc shape of a radius of curvature within a range of 1 to 32 mm, and the inside angle part between the adjacent two basic cell walls has a rounded surface of a circular arc shape of a radius of curvature within a range of 0.1 to 0.4 mm, and a total sum of volumes of cores of not less than 40 μm diameter in the hexagonal cell honeycomb structure body is not more than 0.02 cm 3 /g.