Ngk Insulators, Inc.

Atsushi Kaneda

Yoshimasa Omiya

Yasushi Noguchi

Takayuki Inoue

Kazumi Mase

Shuichi Ichikawa

Tsuyoshi Watanabe

Takashi Noro

Yoshiyuki Kasai

Naoshi Masukawa

Yusuke Hosoi

Yoshimasa Kondo

Tadato Ito

Shungo Nagai

Aiko Otsuka

Kazumi Nagareda

Mariko Kusabe

Mariko Kakitani

Masashi Marada

A honeycomb structure including: a tubular honeycomb structure part having porous partition walls with which a plurality of cells are formed, and an outer peripheral wall; and a pair of electrode parts arranged on a side surface of the honeycomb structure part, an electrical resistivity of the honeycomb structure part is from 1 to 200 &#x3a9;cm, each of the pair of electrode parts is formed into a band-like shape extending in a direction in which the cells extend, in a cross section perpendicular to the extending direction of the cells, the one electrode part is disposed opposite to the other electrode part via the center of the honeycomb structure part, and a total of heat capacities of the pair of electrode parts is from 2 to 150% of a heat capacity of the whole outer peripheral wall.

Honeycomb structure

A honeycomb structure including a tubular honeycomb structure portion having: porous partition walls with which a plurality of cells extending from one end surface to the other end surface are formed to partition through channels of a fluid; and an outer peripheral wall positioned on an outermost periphery, an electrical resistivity of the partition walls is from 1 to 200 &#x3a9;cm, at least a part of the outer peripheral wall is formed by a low Young's modulus portion configured to have a Young's modulus lower than that of the partition walls, and a ratio of the Young's modulus of the low Young's modulus portion to the Young's modulus of the partition walls is from 2 to 95%. Provided is a honeycomb structure which is a catalyst carrier and also functions as a heater when a voltage is applied thereto and which has an excellent heat shock resistance.

A honeycomb structure includes a tubular honeycomb structure body including porous partition walls defining a plurality of cells, and an outer peripheral wall and a pair of electrode parts disposed on a side face of the honeycomb structure body, wherein the honeycomb structure body has electric resistivity of 1 to 200 &#x3a9;cm, each electrode part has a belt-like shape extending in an extending direction of the cells, each electrode part is placed on an opposite side each other across a center of the honeycomb structure body, the honeycomb structure body includes an inflow-side area that is an area on the inflow-side and covering the inflow end face, and an outflow-side area that is an area other than the inflow-side area, and the inflow-side area is made of a material having electric resistivity lower than electric resistivity of a material of the outflow-side area.

Honeycomb structure and method for manufacturing the same

A honeycomb structure includes a tubular honeycomb structure body having porous partition walls to define and form a plurality of cells and an outer peripheral wall, and a pair of electrodes disposed on a side surface of the honeycomb structure body. An electrical resistivity of the honeycomb structure body is from 1 to 200 &#x3a9;cm, each of the pair of electrodes is formed into a band-like shape extending in an extending direction of the cells of the honeycomb structure body, one electrode in the pair of electrodes is disposed on a side opposite to the other electrode in the pair of electrodes via a center of the honeycomb structure body, the honeycomb structure body has a central region and an outer peripheral region, and an electrical resistivity of the central region is lower than an electrical resistivity of the outer peripheral region.

Honeycomb structure and manufacturing method of the same

A honeycomb structure includes a tubular honeycomb structure body having porous partition walls to define and form a plurality of cells and an outer peripheral wall, and a pair of electrodes disposed on a side surface of the honeycomb structure body. An electrical resistivity of the honeycomb structure body is from 1 to 200 &#x3a9;cm, each of the pair of electrodes is formed into a band-like shape extending in an extending direction of the cells of the honeycomb structure body, one electrode in the pair of electrodes is disposed on a side opposite to the other electrode in the pair of electrodes via a center of the honeycomb structure body, the honeycomb structure body is constituted of an outer peripheral region and a central region, and an electrical resistivity of a material constituting the outer peripheral region is lower than an electrical resistivity of a material constituting the central region.

A honeycomb structure includes a tubular bonded honeycomb segment assembly having a plurality of honeycomb segments and a bonding layer which bonds side surfaces of the plurality of honeycomb segments to each other; and a pair of electrode members disposed on a side surface of the bonded honeycomb segment assembly, a volume resistivity of each of the honeycomb segments is from 1 to 200 &#x3a9;cm, at least a part of the bonding layer is made of a bonding material having a conductivity, a volume resistivity of the bonding layer is from 2 to 2000 &#x3a9;cm, and each of the pair of electrode members is formed into a band-like shape extending in an extending direction of the cells of the bonded honeycomb segment assembly, and one electrode member is disposed on a side opposite to the other electrode member via a center of the bonded honeycomb segment assembly.

A honeycomb structure includes a center part which has a cylindrical honeycomb structure part with a porous partition wall and an outer circumferential wall defining a plurality of cells, and which has a pair of electrodes disposed on the side surface of the honeycomb structure part. The honeycomb structure also includes an outer circumferential part disposed around the center part. The electric resistivity of the honeycomb structure part is 1-200 &#x3a9;cm. Each electrode in the electrode pair is formed in a band shape that extends in the direction that the cells extend. In a cross section, one electrode is located opposite the other electrode over the center of the honeycomb structure part. The outer circumferential part has a porous partition wall and an outer circumferential wall that define a plurality of cells. The volumetric heat capacity of the outer circumferential part is smaller than that of the center part.

Provided is a method for producing a silicon carbide ceramic easily and simply producing a silicon carbide ceramic having a small amount in resistivity change due to temperature change and being capable of generating heat by current application; and having a forming raw material preparing step of mixing two or more kinds of silicon carbide ceramic powders containing 4H&#x2014;SiC silicon carbide crystals at respectively different content ratio to prepare a forming raw material; a forming step of forming the forming raw material into a formed body; and a firing step of firing the formed body to produce a silicon carbide ceramic being adjusted at a content ratio of 4H&#x2014;SiC silicon carbide crystal to a desired value.

Method for producing silicon carbide ceramic and method for producing honeycomb structure

A silicon carbide ceramic is provided which has a small amount of resistivity change due to changes in temperature and which is capable of generating heat by current application. The silicon carbide ceramic contains silicon carbide crystals having 0.1 to 25 mass % of 4H&#x2014;SiC silicon carbide crystals and 50 to 99.9 mass % of 6H&#x2014;SiC silicon carbide crystals, preferably having a nitrogen content of 0.01 mass % or less, more preferably containing two or more kinds of silicon carbide particles containing silicon carbide crystals and silicon for binding the silicon carbide particles to each other and having a silicon content of from 10 to 40 mass %.

Silicon carbide ceramic and honeycomb structure

A honeycomb structure includes: a honeycomb structural portion having porous partition walls functioning as fluid passages and separating and forming a plurality of cells extending from one end face to the other end face. The partition walls and the outer peripheral wall contain silicon carbide particles as a framework and silicon as a binder for binding the silicon carbide particles. The honeycomb structure has a partition walls thickness of 50 to 200 &#x3bc;m, a cell density of 40 to 150 cells/cm, and an average particle diameter of the silicon carbide as a framework of 3 to 40 &#x3bc;m. The honeycomb structural portion has a volume resistivity of 1 to 40 &#x3a9;cm at 400&#xb0; C., and the volume resistivity of the electrode portion at 400&#xb0; C. is not more than 40% of the volume resistivity of the honeycomb structural portion at 400&#xb0; C.

The honeycomb structure is provided with a honeycomb structural section, a pair of lateral electrodes on the side face of the honeycomb structural section, and at least one intermediate layer between the honeycomb structural section and the lateral electrodes. The honeycomb structural section has silicon carbide particles having an average particle diameter of 3 to 40 &#x3bc;m and silicon, and the ratio (Si/SiC) of silicon (Si) to silicon carbide (SiC) is 10/90 to 40/60. The lateral electrodes have an average particle diameter of the silicon carbide particles of 10 to 70 &#x3bc;m and a Si/SiC ratio of 20/80 to 50/50. The intermediate layer has an average particle diameter of silicon carbide particles and Si/SiC between those of the honeycomb structural section and those of the lateral electrodes. The electric resistance between the lateral electrodes of the honeycomb structural section is 2 to 100&#x3a9;.

There is disclosed a honeycomb structure including a honeycomb structure section including: porous partition walls to divide and form a plurality of cells which extend from one end surface to the other end surface and become through channels of a fluid; and an outer peripheral wall positioned in an outermost periphery. The partition walls and the outer peripheral wall contain silicon carbide particles as an aggregate, and silicon as a binder to bind the silicon carbide particles, thicknesses of the partition walls are from 50 to 200 &#x3bc;m, a cell density is from 50 to 150 cells/cm, an average particle diameter of silicon carbide as the aggregate is from 3 to 40 &#x3bc;m, and a volume resistivity at 400&#xb0; C. is from 1 to 40 &#x3a9;cm.

A method for producing an aluminum titanate ceramic, which comprises subjecting, to forming, a raw material for aluminum titanate formation, containing NaO-containing &#x3b1;-alumina particles, to obtain a formed body and then firing the body, wherein the &#x3b1;-alumina particles has such a crystal structure that the ratio of the average value of the average length in axis a direction and the average length in axis b direction, to the average length H in axis c direction is 3 or more.

Method for producing aluminum titanate ceramic

There is disclosed a honeycomb structurehaving a plurality of cellspartitioned by cell wallsto function as fluid passages, a predetermined cellbeing plugged by a plugging material at one end face, a remaining cellbeing plugged by the plugging material at the other end face, wherein a Young's modulus of the plugging material is lower than that of the cell wall. A strength of the plugging material is lower than that of the cell wall. A porosity of the plugging material is 97% or more of that of the cell wall. There is provided a honeycomb structure whose end face is not easily cracked and which is superior in durability.

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Nagoya, Japan

Atsushi Kaneda