Patent 9649587 was granted and assigned to Hitachi on May, 2017 by the United States Patent and Trademark Office.
A ceramic honeycomb structure including large numbers of flow paths partitioned by porous cell walls; (a) the cell walls having porosity of 55-65%; and (b) in a pore diameter distribution in the cell walls measured by mercury porosimetry, (i) pore diameters at cumulative pore volumes corresponding to specific percentages of the total pore volume being within specific ranges and satisfying specific relationships; (ii) the difference of a logarithm of the pore diameter at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of the pore diameter at 80% being 0.39 or less; and (iii) the volume of pores of more than 100 μm being 0.05 cm3/g or less.