US 11,872,721 B2
Method for producing conductive honeycomb structure and method for producing electrically heating support
Moriaki Matoba, Nagoya (JP); Masahiro Tokuda, Kasugai (JP); and Hiroki Kitabayashi, Nagoya (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Dec. 22, 2021, as Appl. No. 17/645,470.
Claims priority of application No. 2021-032968 (JP), filed on Mar. 2, 2021; and application No. 2021-165767 (JP), filed on Oct. 7, 2021.
Prior Publication US 2022/0281136 A1, Sep. 8, 2022
Int. Cl. B28B 3/26 (2006.01); B28B 11/24 (2006.01); B01D 46/24 (2006.01); C04B 38/00 (2006.01); F01N 3/027 (2006.01); B28B 17/00 (2006.01); C04B 111/94 (2006.01); C04B 111/00 (2006.01)
CPC B28B 3/269 (2013.01) [B01D 46/2429 (2013.01); B01D 46/24491 (2021.08); B28B 11/243 (2013.01); B28B 17/0081 (2013.01); C04B 38/0006 (2013.01); C04B 38/0009 (2013.01); C04B 38/0051 (2013.01); F01N 3/027 (2013.01); C04B 2111/0081 (2013.01); C04B 2111/94 (2013.01); F01N 2240/16 (2013.01); F01N 2330/06 (2013.01); F01N 2330/30 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for producing a conductive honeycomb structure, the method comprising:
a forming step of extruding a forming raw material containing a conductive ceramic raw material to obtain a honeycomb formed body, the honeycomb formed body comprising: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells to form a flow passage extending from one end face to an other end face;
a drying step of drying the honeycomb formed body to obtain a honeycomb dried body; and
a firing step of firing the honeycomb dried body to obtain a honeycomb fired body,
wherein the forming step comprises a step of controlling a volume fraction of a portion that can form pores of the honeycomb formed body so that an absolute value of a difference in the volume fraction of the portion that can form the pores in predetermined regions of the honeycomb formed body relative to a previously set, predetermined porosity of the honeycomb fired body is within 0.5%; and
wherein the predetermined porosity is a porosity preset for each of the predetermined regions in a cross section perpendicular to a flow passage direction of the cells of the honeycomb fired body.