COMPOSITIONS FOR APPLYING TO HONEYCOMB BODIES

• US 20100252497A1
• Filed: 11/21/2008
• Published: 10/07/2010
• Est. Priority Date: 11/30/2007
• Status: Abandoned Application

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Tepesch, Patrick D., Ellison, Adam J., Shustack, Paul J., Keegan, Kimberly M.
• Application Number:
  US12/741,083
• Publication Number:
  US 20100252497A1
• Time in Patent Office: Days
• US Class Current: 210/500.100
• CPC Class Codes: C03C 10/0045 containing SiO2, Al2O3 and MgO as main constituents
• CPC Class Codes: C03C 8/02 Frit compositions, i.e. in a powdered or comminuted form
• CPC Class Codes: C03C 8/24 Fusion seal compositions being frit compositions having non-frit additions, i.e. for use as seals between dissimilar materials, e.g. glass and metal; Glass solders
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2235/3201 Alkali metal oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3203 Lithium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3409 Boron oxide, borates, boric acids, or oxide forming salts thereof, e.g. borax
• CPC Class Codes: C04B 2235/3481 Alkaline earth metal alumino-silicates other than clay, e.g. cordierite, beryl, micas such as margarite, plagioclase feldspars such as anorthite, zeolites such as chabazite
• CPC Class Codes: C04B 2235/36 Glass starting materials for making ceramics, e.g. silica glass
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/606 Drying
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6565 Cooling rate
• CPC Class Codes: C04B 2235/72 Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/79 Non-stoichiometric products, e.g. perovskites (ABO3) with an A/B-ratio other than 1
• CPC Class Codes: C04B 2235/96 : Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9607 : Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 2235/9615 : Linear firing shrinkage
• CPC Class Codes: C04B 35/00 : Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 35/195 : Alkaline earth aluminosilicates, e.g. cordierite or anorthite
• CPC Class Codes: C04B 35/6263 : characterised by their solids loadings, i.e. the percentage of solids
• CPC Class Codes: C04B 35/62655 : Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
• CPC Class Codes: C04B 38/0006 : Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0012 : characterised by the material used for sealing or plugging (some of) the channels of the honeycombs
• CPC Class Codes: C04B 38/0054 : the pores being microsized or nanosized
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4539 : as a emulsion, dispersion or suspension
• CPC Class Codes: C04B 41/5024 : Silicates C04B41/5022 takes precedence; silico-fluorides C04B41/5018
• CPC Class Codes: C04B 41/87 : Ceramics

Abstract

Disclosed are compositions for applying to honeycomb substrates. The compositions comprise an inorganic powder batch composition; a binder; and a liquid vehicle. The inorganic powder batch composition comprises a ceramic forming glass powder. The compositions are well suited for use as plugging compositions for forming ceramic diesel particulate wall flow filters. Also disclosed herein are end plugged wall flow filters comprising the disclosed plugging compositions and methods for the manufacture thereof. The glass powder forms crystalline cordierite.

Claims

1. A composition for applying to a honeycomb body, comprising:

an inorganic powder batch composition comprising a cordierite forming glass powder, wherein the cordierite forming glass powder is substantially absent of manganese; and

a liquid vehicle;

wherein the composition can be sintered and ceramed to provide a ceramed crystalline phase cordierite composition having a coefficient of thermal expansion (CTE)≦

25×

10<sup>−

7</sup>/°

C.

2. The composition of claim 1, wherein the cordierite forming glass powder comprises, on an oxide percent basis, of:

49% to 55% SiO₂;

13% to 19% MgO; and

26% to 36% Al₂O₃.

3. The composition of claim 1, wherein the inorganic powder batch composition further comprises powdered cordierite.

4. The composition of claim 1, wherein the cordierite forming glass powder has a median particle size diameter dp₅₀ in the range of from 8 to 12 micrometers.

5. The composition of claim 3, wherein the powdered cordierite has a median particle size diameter dp₅₀ less than or equal to 50 micrometers.

6. The composition of claim 3, wherein the weight of the powdered cordierite is present in a ratio relative to the weight of powdered cordierite forming glass in a range of from 1:

4 to 4;

1.

7. The composition of claim 1, wherein the composition can be sintered and ceramed at a temperature T≦

1000°

C. to provide a ceramed crystalline phase cordierite composition having a coefficient of thermal expansion (CTE)≦

25×

10<sup>−

7</sup>/°

C.

8. The composition of claim 7, wherein the composition can be sintered and ceramed at a temperature T≦

1000°

C. to provide a ceramed crystalline phase ceramic composition having a coefficient of thermal expansion (CTE) in the range of from 16×

10<sup>−

7</sup>/°

C. to 21×

10<sup>−

7</sup>1°

C.

9. The composition of claim 7, wherein the temperature T is in the range of from 800°

C. to 1000°

C.

10. The composition of claim 1, wherein the composition further comprises at least one processing aid selected from a plasticizer, lubricant, surfactant, sintering aid, rheology modifier, and pore former.

11. The composition of claim 1, wherein the liquid vehicle comprises water.

12. The composition of claim 1, further comprising an organic binder.

13. The composition of claim 12, wherein the organic binder comprises a cellulose ether.

14. A composition for applying to a honeycomb body, comprising:

an inorganic powder batch composition comprising a cordierite forming glass powder; and

a liquid vehicle;

wherein the composition can be sintered and ceramed at a temperature T<

950°

C. to provide a ceramed crystalline phase cordierite composition having a coefficient of thermal expansion (CTE)≦

25×

10<sup>−

71</sup>°

C.

15. The composition of claim 14, wherein the cordierite forming glass powder comprises, on an oxide percent basis, of:

49% to 55% SiO₂;

13% to 19% MgO; and

26% to 36% Al₂O₃.

16. The composition of claim 14, wherein the inorganic powder batch composition further comprises powdered cordierite.

17. The composition of claim 16, wherein the weight of the powdered cordierite is present in a ratio relative to the weight of powdered cordierite forming glass in a range of from 1:

4 to 4;

1.

18. The composition of claim 14, wherein the composition can be sintered and ceramed at a temperature T≦

950°

C. to provide a ceramed crystalline phase ceramic composition having a coefficient of thermal expansion (CTE) in the range of from 16×

10<sup>−

7</sup>/°

C. to 21×

10<sup>−

7</sup>/°

C.

19. The composition of claim 14, wherein the composition further comprises at least one processing aid selected from a plasticizer, lubricant, surfactant, sintering aid, rheology modifier, and pore former

20. The composition of claim 14, wherein the liquid vehicle comprises water.

21. The composition of claim 14, further comprising an organic binder.

22. The composition of claim 21, wherein the organic binder comprises a cellulose ether.

23. A porous ceramic wall flow filter, comprising:

a honeycomb substrate defining a plurality of cell channels bounded by porous channel walls that extend longitudinally from an upstream inlet end to a downstream outlet end;

a first portion of the plurality of cell channels comprise a ceramed end plug sealed to the respective channel walls at the downstream outlet end to form inlet cell channels and a second portion of the plurality of cell channels comprise a ceramed end plug sealed to the respective channel walls at the upstream inlet end to form outlet cell channels;

wherein the ceramed end plugs are formed from a plugging composition comprising;

an inorganic powder batch composition comprising a cordierite forming glass powder, cordierite powder, and a liquid vehicle;

wherein the plugging composition is sintered and ceramed at a temperature T 1000°

C.

24. A method for manufacturing a porous ceramic wall flow filter, comprising the steps of:

providing a honeycomb structure defining a plurality of cell channels bounded by channel walls that extend longitudinally from an upstream inlet end to a downstream outlet end;

selectively plugging an end of at least one predetermined channel with a plugging composition comprising;

an inorganic powder batch composition comprising a cordierite forming glass powder comprising, on an oxide percent basis, of;

49% to 55% SiO₂;

13% to 19% MgO; and

26% to 36% Al₂O₃;

powdered cordierite, and

a liquid vehicle; and

firing the selectively plugged honeycomb body under conditions effective to convert the plugging composition into a crystalline phase cordierite plug in the at least one selectively plugged channel.

25. The method of claim 24, wherein the honeycomb body is a green body and wherein the step of firing the selectively plugged honeycomb body comprises heating the selectively plugged honeycomb body under conditions effective to convert the green honeycomb body into a ceramic honeycomb body.