Ngk Insulators, Inc.

Yukio Mizuno

Yukio Miyairi

Naomi Noda

Toshio Yamada

Jungo Kondo

Minoru Imaeda

Yasushi Noguchi

Atsuo Kondo

Yukari Nakane

A honeycomb filter including partition walls having a porous partition wall base material and a surface layer provided on only inflow side or both inflow and outflow sides of the partition wall base material, and satisfying the following conditions capable of using as a DPF. The surface layer has a peak pore diameter of from 0.3 &#x3bc;m to 20 &#x3bc;m (exclusive) being equal to or smaller than the average pore diameter of the base material; the porosity of from 60% to 95% (exclusive) when measured by mercury porosimetry being larger than that of the base material; and the thickness Lof from 0.5% to 30% (exclusive) of the partition wall thickness L; and mass per filtration area of from 0.01 mg/cmto 6 mg/cm(exclusive). The base material has an average pore diameter of from 10 &#x3bc;m to 60 &#x3bc;m (exclusive) and a porosity of from 40% to 65% (exclusive).

Honeycomb filter

A honeycomb filterof the present invention includes a honeycomb structurehaving partition wallsand plugging portions, and the partition wallsare constituted of a porous layer in which a first wall portionhaving an average pore diameter of 20 &#x3bc;m or more and carrying an oxidation catalyston the inner surfaces of formed pores, a second wall portionfunctioning as a buffer and having a high porosity, and a third wall portionhaving an average pore diameter of 1 to 15 &#x3bc;m and a porosity of 50 to 90% are laminated in the thickness direction of the partition wallsfrom a surface side where cellshaving opening end portions opened on an inflow side and opening end portions plugged on an outflow side are defined.

A honeycomb filter system comprising a first honeycomb filter disposed upstream: first filter having partition wall matrix of a mean pore diameter of 25 &#x3bc;m or more and below 70 &#x3bc;m and a porosity of 40% or more and below 70%, and carrying an oxidation catalyst containing at least one material selected from the group consisting of platinum (Pt), palladium, ceria, and alumina in at least a part of inner surfaces of pores of the matrix; and a second honeycomb filter disposed downstream; having a surface layer of a peak pore diameter of 0.3 &#x3bc;m or more and below 20 &#x3bc;m which is equivalent to or smaller than that of its matrix, and a porosity of 60% or more and below 95% which is higher than that of the matrix; and having the other specified relations.

Honeycomb filter system

A honeycomb structure having porous partition walls having a large number of pores, formed so as to produce a plurality of cells each extending between the two ends of the honeycomb structure, and plugged portions formed so as to plug the cells at either one end of the honeycomb structure or at the insides of the cells, wherein the honeycomb structure has the partition walls of a permeability of 7&#xd7;10to 4&#xd7;10m. The honeycomb structure can provide a honeycomb catalyst structure which is superior in purification efficiency, is low in pressure loss and can be mounted even in a limited space.

Honeycomb structure and honeycomb catalytic body

Major surface of a substrate having an optical waveguide and a modulation electrode is pasted to a base substrate through a thermosetting resin, and then the rear surface of the substrate is machined thus making thin the entirety. Subsequently, the rear surface of the substrate thus rendered thin is subjected to machining or laser machining to form a thin part, which is further subjected to machining or laser machining to form a first thin part at a part, including the optical waveguide, of the thin part and a second thin part thinner than the first thin part contiguously thereto. Thereafter, the rear surface of the substrate is pasted to the major surface of a supporting substrate through a thermosetting resin and the base substrate is stripped thus obtaining an optical modulator.

Growing community of inventors

Komaki, Japan

Yukio Mizuno