US 12,187,650 B2
Silicon carbide ceramic honeycomb structure and its production method
Kenichiro Shimizu, Fukuoka (JP)
Assigned to PROTERIAL, LTD., Tokyo (JP)
Filed by PROTERIAL, LTD., Tokyo (JP)
Filed on Apr. 19, 2024, as Appl. No. 18/640,593.
Application 18/640,593 is a continuation of application No. 18/037,677, previously published as PCT/JP2022/013577, filed on Mar. 23, 2022.
Claims priority of application No. 2021-054390 (JP), filed on Mar. 26, 2021.
Prior Publication US 2024/0262755 A1, Aug. 8, 2024
Int. Cl. C04B 35/565 (2006.01); C04B 35/63 (2006.01); C04B 38/00 (2006.01)
CPC C04B 35/565 (2013.01) [C04B 35/6303 (2013.01); C04B 38/0009 (2013.01); C04B 38/0054 (2013.01); C04B 38/0074 (2013.01); C04B 2235/3826 (2013.01); C04B 2235/6021 (2013.01); C04B 2235/606 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A silicon carbide ceramic honeycomb structure having large numbers of axially penetrating flow paths partitioned by porous silicon carbide cell walls,
the silicon carbide ceramic honeycomb structure being formed by integrally bonding large numbers of honeycomb segments by binder layers, so as to have an outer periphery having a circular shape in a cross section perpendicular to the axial direction, and forming an outer peripheral wall on the outer periphery,
each honeycomb segment being composed of a sintered body of ceramic particles comprising aggregate and a binder,
said binder being at least one selected from the group consisting of alumina particles, aluminum hydroxide particles, magnesium oxide particles, and magnesium hydroxide particles,
said cell walls having porosity of 40-50% and a median pore diameter of 8-18 μm, and
when a straight line C is drawn in parallel with the cell wall surface such that it passes a center in the direction of the thickness T of said cell wall, and straight lines are drawn in parallel with said straight line C such that they are separate from said straight line C by ±T/5 and ±2T/5 in the thickness direction of said cell wall, to measure the lengths (pore widths) of pore portions crossing each straight line, and the number of pores crossing each straight line, in a cell wall cross section perpendicular to the axial direction,
an average pore width W determined by averaging the lengths (pore widths) of all measured pore portions being 10-25 μm,
the number N of pores per length determined by dividing the total number of the measured pores by the total length of the straight lines used for measurement being 20-40/mm,
the volume of pores having pore diameters of 20 μm or more being 10-20% of the total pore volume in said cell walls, and the volume of pores having pore diameters of 9 μm or less being 3-25% of the total pore volume in said cell walls, in the relation between the pore diameter and cumulative pore volume of said cell walls measured by mercury porosimetry.