Bonding material, process for producing the same, and honeycomb structure made with the same

• US 8,039,086 B2
• Filed: 06/12/2008
• Issued: 10/18/2011
• Est. Priority Date: 12/14/2005
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Fujita, Hiroki, Tomita, Takahiro
• Primary Examiner(s): BALDWIN, GORDON
• Application Number:
  US12/138,076
• Publication Number:
  US 20080248238A1
• Time in Patent Office: 1,223 Days
• Field of Search: None
• US Class Current: 428/116
• CPC Class Codes: B01D 2265/04 Permanent measures for connecting different parts of the filter, e.g. welding, glueing or moulding
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/2448 of the adhesive layers, i.e. joints between segments
• CPC Class Codes: B01D 46/24494 Thermal expansion coefficient, heat capacity or thermal conductivity
• CPC Class Codes: B01D 46/24495 Young's modulus
• CPC Class Codes: B01D 46/2478 Structures comprising honeycomb segments
• CPC Class Codes: B01D 46/2498 The honeycomb filter being defined by mathematical relationships
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2237/06 Oxidic interlayers
• CPC Class Codes: C04B 2237/062 based on silica or silicates
• CPC Class Codes: C04B 2237/068 based on refractory oxides, e.g. zirconia
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/185 Mullite 3Al2O3-2SiO2
• CPC Class Codes: C04B 35/195 Alkaline earth aluminosilicates, e.g. cordierite or anorthite
• CPC Class Codes: C04B 35/478 based on aluminium titanates
• CPC Class Codes: C04B 35/563 based on boron carbide
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 35/597 : based on silicon oxynitride, e.g. SIALONS
• CPC Class Codes: C04B 37/005 : consisting of glass or ceramic material
• CPC Class Codes: C04B 38/0019 : characterised by the material used for joining separate subunits
• CPC Class Codes: C04B 38/0074 : expressed as porosity percentage
• CPC Class Codes: Y10T 428/24149 : Honeycomb-like

Abstract

There is provided bonding material having a Young'"'"'s Modulus after hardening of not less than 20% of articles to be bonded, and an average linear coefficient of thermal expansion after hardening of not more than 70% of the articles to be bonded. This bonding material can suppress deformation of a honeycomb segment due to thermal stress to be generated by a bonding material layer and can suitably be used at the time of manufacturing exhaust gas trapping filters capable of reducing the generation of defects such as a crack, and above all, a diesel particulate filter (DPF) for trapping particulate matter (particulates) in exhaust gas from the diesel engine.

Claims

1. A bonding material composition comprising two or more fillers and a matrix, the fillers including:

at least one or more fillers selected from the group consisting of cordierite, beta-spodumene, amorphous silica, aluminum titanate, and zirconium phosphate;

at least one or more fillers selected from the group consisting of silicon carbide, alumina, quartz, aluminum nitride, B₄C, mullite, SiAlON, silicon nitride, zirconia, cordierite, aluminum titanate, zirconium phosphate, boron nitride, talc, mica, and glass flake,

wherein the fillers are 10-95% by volume of the bonding material composition, the matrix is 5-90% by volume of the bonding material, and a volume ratio of a first filler of the two or more fillers to a second filler of the two or more fillers is 5;

95 to 95;

5; and

at least one of the fillers and the matrix is selected so as to have a Young'"'"'s Modulus after hardening not less than 20% of that of articles to be bonded, and an average linear coefficient of thermal expansion after hardening not more than 70% of that of the articles to be bonded.

2. The bonding material composition according to claim 1, including:

at least one or more fillers selected from the group consisting of cordierite, aluminum titanate and zirconium phosphate, and

a matrix.

3. A bonding material having the bonding material composition according to claim 1.

4. The bonding material according to claim 3, wherein said average linear coefficient of thermal expansion is not more than 3×

10<sup>−

6</sup>·

K<sup>−

1</sup>.

5. The bonding material according to claim 3, wherein the first filler has an average linear coefficient of thermal expansion of not more than 50% of the articles to be bonded;

and the second filler has a Young'"'"'s Modulus of not less than 100 GPa.

6. The bonding material according to claim 5, wherein the second filler contains flat particles.

7. The bonding material according to claim 5, wherein the average coefficient of thermal expansion of the first filler is not more than 2.5×

10<sup>−

6</sup>·

K<sup>−

1</sup>.

8. The bonding material according to claim 3, wherein the two or more fillers have an average coefficient of thermal expansion of not more than 2.5×

10<sup>−

6</sup>·

K<sup>−

1</sup>.

9. The bonding material according to claim 3, wherein the two or more fillers are selected from the group consisting of cordierite, aluminum titanate, and zirconium phosphate.

10. The bonding material according to claim 3, wherein said matrix is an inorganic adhesive.

11. The bonding material according to claim 10, wherein said inorganic adhesive is colloidal silica.

12. The bonding material according to claim 3, wherein a bonding temperature with the articles to be bonded is not more than 1000°

C.

13. The bonding material according to claim 3, wherein the articles to be bonded are honeycomb segments.

14. A process for producing a bonding material, wherein the process includes a step of obtaining a paste-like bonding material composition by mixing and kneading a filler and a matrix according to claim 1.

15. A ceramic structure manufactured by bonding a plurality of ceramic members by a bonding material according to claim 3.

16. A honeycomb structure manufactured by bonding a plurality of honeycomb segments by a bonding material according to claim 3.