1. Field of the Invention
The present invention relates to a honeycomb structural body.
2. Description of the Related Art
Conventionally, a honeycomb structural body is provided in an exhaust gas treating apparatus used for treating HC, CO, NOX and the like included in exhaust gas discharged from automobiles. This honeycomb structural body has plural cells (through holes) which extend, along a longitudinal direction, from one end face to the other end face of the honeycomb structural body. These cells are separated from one another by cell walls.
For example, when the honeycomb structural body is used as a catalyst carrier, the cell walls support a catalyst such as platinum. When exhaust gas passes through such a catalyst carrier, components such as HC, CO, NOX and the like included in the exhaust gas are converted by catalyst reactions and the like, because the cell walls support the catalyst. Accordingly, the exhaust gas can be treated.
Such a honeycomb structural body is manufactured as follows. First, pillar-shaped honeycomb units having the same shape are joined together by interposing adhesive layers between the side faces of the honeycomb units. Accordingly, a predetermined number of honeycomb units are joined together. Then, the periphery of this assembly of honeycomb units is cut into a desired shape.
The honeycomb units primarily include inorganic particles, inorganic fiber, and an inorganic binder. There is a proposal for using honeycomb units including inorganic particles which is alumina or ceria (see, for example, WO 2005/063653).
Contents of WO 2005/063653 are incorporated herein by reference in their entirety.