Production method of ceramic honeycomb structure, and ceramic honeycomb structure

Patent metadata

Field	Value
Publication number	US-9840444-B2
Application number	US-201214350925-A
Country	US
Kind code	B2
Filing date	Oct 9, 2012
Priority date	Oct 11, 2011
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having large numbers of longitudinal cells partitioned by porous cell walls having porosity of 50% or more, and a peripheral wall formed on a peripheral surface of the ceramic honeycomb body, comprising the steps of extruding moldable ceramic material to form a honeycomb-structured ceramic green body; machining a peripheral portion of the green body or a sintered body obtained from the green body to remove part of cell walls in the peripheral portion to obtain a ceramic honeycomb body having longitudinal grooves on a peripheral surface; applying colloidal metal oxide to a peripheral surface of the ceramic honeycomb body and drying it, and then applying a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form the peripheral wall.

First claim

What is claimed is:

1. A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having a plurality of longitudinal cells partitioned by porous cell walls having a porosity of 50% or more, and a peripheral wall formed on a peripheral surface of said ceramic honeycomb body, comprising the steps of
extruding a moldable ceramic material to form a honeycomb-structured ceramic green body;
machining a peripheral portion of said green body or a sintered body obtained from said green body to remove part of cell walls in the peripheral portion, thereby obtaining a ceramic honeycomb body having longitudinal grooves on a peripheral surface;
coating said ceramic honeycomb body with a composition consisting of an aqueous dispersion of colloidal metal oxide so that the colloidal metal oxide intrudes into pores in cell walls constituting the grooves on the peripheral surface, wherein said coating clogs the pores so that the porosity of said cell walls constituting the grooves on the peripheral surface is 0.9 times or less a porosity of cell walls in an inner portion of the ceramic honeycomb body, and drying it; and
further coating said peripheral surface coated with the composition consisting of the aqueous dispersion of colloidal metal oxide with a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form said peripheral wall.

2. The method for producing a ceramic honeycomb structure according to claim 1 , wherein said colloidal metal oxide is colloidal silica or colloidal alumina.

3. The method for producing a ceramic honeycomb structure according to claim 1 , wherein the amount of said colloidal metal oxide coated is 2.0×10 −3 -150×10 −3 g/cm 3 on a solid basis, per a unit volume of said ceramic honeycomb body.

4. The method for producing a ceramic honeycomb structure according to claim 1 , wherein said colloidal metal oxide has an average particle size of 5-100 nm.

Assignees

• Hitachi Metals Ltd

Inventors

• Okazaki Shunji

Classifications

• F01N3/2828

  Ceramic multi-channel monoliths, e.g. honeycombs · CPC title

• C04B41/52

  Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation} · CPC title

• Y10T428/24149

  Honeycomb-like · CPC title

• C04B41/009

  characterised by the material treated · CPC title

• C04B2111/0081

  as catalysts or catalyst carriers · CPC title