Porous material, honeycomb structure, and method of producing porous material

Patent metadata

Field	Value
Publication number	US-11428138-B2
Application number	US-201715782093-A
Country	US
Kind code	B2
Filing date	Oct 12, 2017
Priority date	Oct 24, 2016
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

A porous material includes an aggregate in which oxide films are formed on surfaces of particle bodies, and a binding material that contains cordierite and binds the aggregate together in a state where pores are formed. The binding material or the oxide films contain a rare-earth component that excludes Ce.

First claim

The invention claimed is:

1. A porous material comprising:
an aggregate in which oxide films are formed on surfaces of particle bodies, said particle bodies including SiC particles; and
a binding material that contains cordierite and binds said aggregate together in a state where pores are formed,
wherein said porous material contains Ce,
said binding material contains a rare-earth component other than Ce, said rare-earth component including Y,
at least part of said rare-earth component exists as , Y 2 Si 2 O 7 ,
a ratio of a mass of said rare-earth component other than Ce in terms of an oxide is in a range of 0.44 to 1.85 mass % of said porous material as a whole,
a percentage of amorphous component in said binding material is less than 50 mass %,
a percentage of said binding material in said porous material is greater than 15.0 mass % and less than or equal to 50 mass %, and
an alkali metal component is contained in said porous material, and a ratio of a mass of said alkali metal component in terms of an oxide is less than 0.1 mass % of said porous material as a whole.

2. The porous material according to claim 1 , wherein said oxide films contain cristobalite.

3. The porous material according to claim 2 , wherein a ratio of a mass of said cristobalite is in a range of 3.0 to 25.0 mass % of said porous material as a whole.

4. The porous material according to claim 1 , wherein said porous material contains Na or K as said alkali metal component.

5. The porous material according to claim 1 , wherein a thermal expansion coefficient in a temperature range of 40° C. to 200° C is less than or equal to 5.5 ppm/K.

6. A honeycomb structure that is a tubular member made of the porous material according to claim 1 and having an interior partitioned into a plurality of cells by partition walls.

7. A method of producing a porous material, comprising:
a) obtaining a compact by molding a mixture of an aggregate raw material, a raw material of binding material, and a pore forming material;
b) obtaining a fired compact by firing said compact at a temperature of 1300 to 1600° C. in an inert atmosphere; and
c) obtaining a porous material by subjecting said fired compact to oxidation treatment at a temperature of 1150 to 1350 ° C. in an oxidizing atmosphere.
wherein said aggregate raw material is a non-oxide material,
said aggregate comprising oxide films formed on surfaces of the particle bodies, said particle bodies including SiC particles,
said raw material of binding material contains a rare-earth component other than Ce, said rare-earth component including Y,
said porous material comprises a binding material that contains cordierite and binds said aggregate together in a state where pores are formed,
said porous material contains Ce,
at least part of said rare-earth component exists in said binding material as Y 2 Si 2 O 7 ,
a ratio of a mass of said rare-earth component other than Ce in terms of an oxide is in a range of 0.44 to 1.85 mass % of said porous material as a whole,
a percentage of amorphous component in said binding material is less than 50 mass %,
a percentage of said binding material in said porous material is greater than 15.0 mass % and less than or equal to 50 mass %, and
an alkali metal component is contained in said porous material, and a ratio of a mass of said alkali metal component in terms of an oxide is less than 0.1 mass % of said porous material as a whole.

Assignees

• Ngk Insulators Ltd

Inventors

• Izumi Yunie
• Tomita Takahiro
• Tsuboi Mika

Classifications

• C04B2235/9607

  Thermal properties, e.g. thermal expansion coefficient · CPC title

• C04B2235/3225

  Yttrium oxide or oxide-forming salts thereof · CPC title

• C04B35/565 Primary

  based on silicon carbide · CPC title

• B01J37/0246

  Coatings comprising a zeolite · CPC title

• B01D2255/30

  Silica · CPC title