Ngk Insulators, Inc.

Yasushi Uchida

Suguru Kodama

Yukio Miyairi

Shuichi Ichikawa

Takahiro Kondo

Masahiro Shirai

Yohei Ono

Atsushi Mizuno

Nobuaki Takahashi

The circumference coating material fills a recessed groove that is formed on a circumferential surface of a honeycomb fired body and extends an axial direction at which a part of cells are opened to the outside and to cover the circumferential surface, thereby forming a circumferential wall on the circumferential surface of a honeycomb structure, and the circumference coating material includes colloidal silica in a part of raw materials to be used and has a chlorine concentration of 150 ppm or less. In addition, the colloidal silica to be used has a chlorine concentration of 500 ppm or less, and the colloidal silica is produced using at least any one acid of sulfuric acid, phosphoric acid, and organic acid.

Circumference coating material, bonding material, honeycomb structure, and method of producing honeycomb structure

A honeycomb filter includes a honeycomb structure and plugged portions. Partition walls of the honeycomb structure are made of a partition wall material including a plurality of aggregates containing silicon carbide or silicon nitride as a main component, and a binding material at a content of 15 to 35 mass %. The binding material is made of a material in which mullite particles as reinforcing particles may be dispersed in cordierite. A thermal expansion coefficient of the partition walls at 40 to 800&#xb0; C. is 4.2&#xd7;101/K or less. When a value of a stress applied to the partition wall material at 900&#xb0; C. is normalized by the maximum value of the stress applied to the partition wall material, a percentage of a plastic deformation displacement in a total displacement at a normalized stress value of 0.9 is in a range of 0.3 to 10%.

Honeycomb filter

In the present invention, a honeycomb structure includes a joined honeycomb segment body in which a plurality of honeycomb segments are integrally joined by mutual joining surfaces via a joining material layer, and has a configuration in which a plurality of cells to become through channels of a fluid are arranged in parallel with one another along a central axis direction. The joining material layer contains, as aggregates, inorganic particles, and acicular crystal particles having a shot content ratio smaller than 10 mass %, and the acicular crystal particles include 80 mass % or more of acicular crystal particles having an average length of 20 to 500 &#x3bc;m in a long axis direction of the acicular crystal particles. As the inorganic particles, silicon carbide, cordierite, alumina, zirconia, yttria or the like can be used, and as natural acicular minerals, sepiolite, wollastonite, palygorskite or the like can be used.

Honeycomb structure

A catalyst body of the present invention includes: a porous carrier in which a large number of aggregate particles containing a main component of a nonoxide ceramic are bonded to one another while a large number of pores are disposed; and a catalyst layer carried on the porous carrier and containing a compound of an alkali metal, wherein the porous carrier has an oxide film unavoidably formed on a part of the surface of the aggregate particles, and an oxide film protective layer formed of a material which does not form low-melting glass with the alkali metal is further disposed between the oxide film and the catalyst layer in such a manner as to coat at least a part of the oxide film.

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Nagoya, Japan

Yasushi Uchida