Crosslinked starches for pore forming in ceramics

• US 10,472,291 B2
• Filed: 09/12/2014
• Issued: 11/12/2019
• Est. Priority Date: 10/15/2013
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Lewis, Mark Alan, Oram, Pascale, Tanner, Cameron Wayne, Vileno, Elizabeth Marie
• Primary Examiner(s): Snelting, Erin
• Application Number:
  US14/484,509
• Publication Number:
  US 20150102516A1
• Time in Patent Office: 1,887 Days
• CPC Class Codes: B28B 3/20 wherein the material is extruded extrusion moulding of plastics B29C48/00
• CPC Class Codes: C04B 2103/42 Pore formers
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 2111/32 Expansion-inhibited materials
• CPC Class Codes: C04B 2235/606 Drying
• 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 35/636 Polysaccharides or derivatives thereof
• CPC Class Codes: C04B 35/638 Removal thereof
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 38/0006 Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0067 characterised by the density of the end product
• CPC Class Codes: C04B 38/0074 expressed as porosity percentage
• CPC Class Codes: C04B 38/0087 by generating pores in the ceramic material while in the molten state
• CPC Class Codes: C04B 38/06 by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
• CPC Class Codes: C04B 38/0645 Burnable, meltable, sublimable materials
• CPC Class Codes: C04B 38/068 Carbonaceous materials, e.g. coal, carbon, graphite, hydrocarbons
• CPC Class Codes: G01N 2033/0091 : Powders
• CPC Class Codes: G01N 33/388 : Ceramics

Abstract

Disclosed herein are green bodies comprising at least one ceramic-forming powder; at least one binder; and at least one cross-linked starch present in an amount of at least about 20% by weight as a super addition. Further disclosed herein is a method of making a porous ceramic body comprising mixing at least one ceramic-forming powder, at least one solvent such as water, at least one binder, and at least one cross-linked starch present in an amount of about 20% by weight as a super addition to form a batch composition; extruding the batch composition to form a green body; drying the green body; and firing the green body to form a porous ceramic body. Also disclosed herein are methods of screening a green body for making a porous ceramic body.

Claims

1. A method of making a porous aluminum titanate body, the method comprising:

mixing at least one aluminum titanate-forming powder, at least one solvent, at least one binder, and at least one cross-linked starch present in an amount greater than 30% by weight as a super addition to form a batch composition;

extruding the batch composition to form a green body;

drying the green body completely; and

firing the green body to form a porous aluminum titanate body,

wherein the cross-linked starch is cross-linked to a degree sufficient to limit growth of the green body at about 35°

C. and about 85% humidity to less than about 0.5% at least about 24 hours after complete drying and before the firing of the green body and to limit the shrinkage upon complete drying of the green body to less than about 4%.

2. The method of making a porous aluminum titanate body according to claim 1, wherein the porosity of the porous aluminum titanate body is greater than about 50%.

3. The method of making a porous aluminum titanate body according to claim 1, wherein the porosity of the porous aluminum titanate body ranges from about 50% to about 65%.

4. The method of making a porous aluminum titanate body according to claim 1, wherein the at least one cross-linked starch is present in the batch composition in an amount ranging from greater than 30% to about 35% by weight as a super addition.

5. The method of making a porous aluminum titanate body according to claim 1, wherein the at least one cross-linked starch is present in the batch composition in an amount ranging from greater than 30% to about 32% by weight as a super addition.

6. The method of making a porous aluminum titanate body according to claim 1, further comprising:

after drying the green body, screening the green body to determine if the green body satisfies at least one of the following parameters;

(i) less than about 4% shrinkage upon drying of the green body; and

(ii) less than about 0.5% growth of the green body at least about 24 hours after complete drying.

7. The method of making a porous aluminum titanate body according to claim 1, wherein the at least one aluminum titanate-forming powder comprises an alumina source, a silica source, a titania source, and a magnesia source.

8. A method of making a porous aluminum titanate body, the method comprising:

mixing at least one aluminum titanate-forming powder, at least one solvent, at least one binder, and at least one cross-linked starch present in an amount of about 28 to 32% by weight as a super addition to form a batch composition;

extruding the batch composition to form a green body;

drying the green body completely; and

firing the green body to form a porous aluminum titanate body,

wherein the cross-linked starch is cross-linked to a degree sufficient to limit growth of the green body at about 35°

C. and about 85% humidity to less than about 0.5% at least about 24 hours after complete drying and before the firing of the green body and to limit the shrinkage upon complete drying of the green body to less than about 4%.