Coating material, outer periphery-coated silicon carbide-based honeycomb structure, and method for coating outer periphery of silicon carbide-based honeycomb structure

Patent metadata

Field	Value
Publication number	US-2019300440-A1
Application number	US-201916363155-A
Country	US
Kind code	A1
Filing date	Mar 25, 2019
Priority date	Mar 30, 2018
Publication date	Oct 3, 2019
Grant date	—

Abstract

A coating material for a silicon carbide-based honeycomb structure, the coating material including from 20 to 75% by mass of ceramic powder (A), the ceramic powder (A) including from 55 to 95% by mass of silicon carbide and from 5 to 30% by mass of silicon dioxide as chemical components.

First claim

What is claimed is:

1 . A coating material for a silicon carbide-based honeycomb structure, the coating material comprising from 20 to 75% by mass of ceramic powder (A), the ceramic powder (A) comprising from 55 to 95% by mass of silicon carbide and from 5 to 30% by mass of silicon dioxide as chemical components.

2 . The coating material according to claim 1 , wherein the ceramic powder (A) has a D50 on volume basis of from 8 to 30 μm, based on a particle size distribution measurement by a laser diffraction/scattering method.

3 . The coating material according to claim 1 , wherein the ceramic powder (A) has a D10 on volume basis of from 1 to 4 μm, and D90 of from 20 to 75 μm (D90>D50), based on a particle size distribution measurement by a laser diffraction/scattering method.

4 . The coating material according to claim 1 , wherein the ceramic powder (A) is grinding scrap or crushed powder of the silicon carbide-based honeycomb structure.

5 . The coating material according to claim 1 , further comprising from 20 to 50% by mass of white or light colored ceramic powder (B).

6 . The coating material according to claim 5 , wherein the ceramic powder (B) comprises at least one selected from the group consisting of cordierite, silicon nitride, alumina, mullite, zirconia, zirconium phosphate, titania and aluminum titanate.

7 . The coating material according to claim 5 , wherein the ceramic powder (B) has a D50 on volume basis of from 1 to 40 μm, based on a particle size distribution measurement by a laser diffraction/scattering method.

8 . The coating material according to claim 1 , wherein a ratio of a thermal expansion coefficient after drying the coating material at 600° C. for 30 minutes to a thermal expansion coefficient of the silicon carbide honeycomb structure is from 0.8 to 1.1.

9 . The coating material according to claim 1 , wherein the coating material further comprises from 0.1 to 4% of hollow particles containing an organic substance, and wherein the hollow particles have a D50 on volume basis of from 35 to 55 μm, based on a particle size distribution measurement by a laser diffraction/scattering method.

10 . An outer periphery-coated silicon carbide-based honeycomb structure, comprising: a silicon carbide-based honeycomb structure; and an outer periphery-coated layer covering an outer periphery of the silicon carbide-based honeycomb structure,
wherein the outer periphery-coated layer comprises from 20 to 75% by mass of ceramic powder (A), the ceramic powder (A) comprising from 55 to 95% by mass of silicon carbide and from 5 to 30% by mass of silicon dioxide as chemical components.

11 . The outer periphery-coated silicon carbide-based honeycomb structure according to claim 10 , wherein the ceramic powder (A) has the same composition as that of the silicon carbide-based honeycomb structure.

12 . The outer periphery-coated silicon carbide-based honeycomb structure according to claim 10 , wherein a ratio of a thermal expansion coefficient of the outer periphery-coated layer to a thermal expansion coefficient of the silicon carbide-based honeycomb structure is from 0.8 to 1.1.

13 . A method for coating an outer periphery of a silicon carbide-based honeycomb structure, the method comprising:
applying the coating material according to claim 1 onto an outer periphery of the silicon carbide-based honeycomb structure and drying the applied coating material to form an outer peripheral coated layer.

Assignees

• Ngk Insulators Ltd

Inventors

• Kodama Suguru

Classifications

• C04B2235/3463

  Alumino-silicates other than clay, e.g. mullite · CPC title

• C04B35/117 Primary

  Composites · CPC title

• C04B41/5059

  Silicon carbide · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B2235/3234

  Titanates, not containing zirconia · CPC title