Patent 7704442 was granted and assigned to NGK Insulators on April, 2010 by the United States Patent and Trademark Office.
A process for producing a honeycomb structure by obtaining clay from a cordierite-forming raw material containing an alumina source, a silica source, and a magnesia source; and forming the clay into a honeycomb shape, wherein a material having, in its volume particle size distribution, a 50 volume % particle size (V50) [μm] of 1 to 25 μm is used, as each of alumina source, silica source, and magnesia source; and a material having, in the volume particle size distribution of the whole cordierite-forming raw material, a ratio of 90 volume % particle size (Vall90) [μm] to 10 volume % particle size (Vall10) [μm] [a volume particle size distribution ratio (Vall90/Vall10)] of 10 or less and a difference (Vall90−Vall10) between 90 volume % particle size (Vall90) [μm] and 10 volume % particle size (Vall10) [μm] of 25 μm or less is used, as the cordierite-forming raw material.