Ngk Insulators, Inc.

Shingo Tokuda

Shuji Ueda

Takayuki Kanetake

Yoshimasa Kondo

Takashi Mizutani

A method for producing a honeycomb structure, the method comprising the steps of: kneading a forming raw material containing a cordierite forming material and then forming it to produce a honeycomb formed body; and firing the honeycomb formed body to provide a honeycomb structure. In the producing method, from 0.1 to 6.0 parts by mass of a magnesium silicate mineral having a 2:1 ribbon type structure per 100 parts by mass of the cordierite forming material is added to the forming raw material.

Method for producing honeycomb structure

A ceramic filter having a pillar-shaped honeycomb structure, wherein when observing a plurality of pores from a surface of partition walls with a laser microscope and plotting an equivalent circle diameter (&#x3bc;m) of each pore on an X-axis and a pore depth (&#x3bc;m) of each pore on a Y-axis on a two-dimensional coordinate system, a slope of a regression line (y/x) obtained by a least squares method in a range of 20&#x2264;x&#x2264;40 is 0 to 0.20, an average value of the pore depth of the plurality of pores is 2.5 &#x3bc;m to 5.0 &#x3bc;m, and a number density of the plurality of pores is 600/mmto 2450/mm.

Ceramic filter

A circumferential coating material to be applied to a circumferential surface of a honeycomb structure made of ceramics formed by extrusion, the circumferential coating material including a ceramic raw material that forms a circumferential coating layer,

Circumferential coating material, circumferential coated honeycomb structure

A plugged honeycomb structure including particulate matter (PM) trapping layers disposed on the surfaces of the partition walls extending up to inflow side end faces of the plugging portions that plug outflow cells so that adjacent PM-trapping layers with the partition walls and the plugging portion therebetween are disposed so as to continue on the inflow side end faces of the plugging portions. The PM-trapping layers are extended up to the inflow side end faces of the plugging portions to form protruding portions having a protrusion height corresponding with 0.1 to 2 times the length of a side of the outflow cells from the inflow side end faces of the plugging portions toward the outside of the cell extension direction.

Plugged honeycomb structure and method for manufacturing the same

The honeycomb filter is constructed as a diesel particulate filter having a filtration function for filtering out the particulate matter included in an exhaust emission of a diesel engine. The honeycomb filter has a honeycomb structure as a base and inlet opening cells with surface layers formed on respective inner surfaces thereof. The surface layer has zero film thickness in an inlet peripheral region. Separation vortexes are generated in the inlet peripheral regions. The zero film thickness of the surface layers in the inlet peripheral regions naturally causes non-flaking of the surface layers induced by the separation vortexes generated in the inlet peripheral regions and thereby leads to non-production of flakes. In the non-existent condition of flakes, the overall surface layers are not collapsed by collision of the flakes.

Growing community of inventors

Nagoya, Japan

Shingo Tokuda