Plasticized mixture and method for stiffening

• US 20080125509A1
• Filed: 11/29/2007
• Published: 05/29/2008
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Fabian, Michelle Dawn, Fewkes, Edward John, McCarthy, Kevin Robert
• Granted Patent: US 8,022,112 B2
• Time in Patent Office: Days
• US Class Current: 522/34
• CPC Class Codes: B29C 48/04 Particle-shaped making granules B29B9/00
• CPC Class Codes: C04B 2111/00129 Extrudable mixtures
• 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 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
• CPC Class Codes: C04B 2235/3445 Magnesium silicates, e.g. forsterite
• CPC Class Codes: C04B 2235/349 Clays, e.g. bentonites, smectites such as montmorillonite, vermiculites or kaolines, e.g. illite, talc or sepiolite
• CPC Class Codes: C04B 2235/6021 Extrusion moulding
• CPC Class Codes: C04B 2235/606 Drying
• CPC Class Codes: C04B 2235/61 Mechanical properties, e.g. fracture toughness, hardness, Young's modulus or strength
• CPC Class Codes: C04B 35/195 Alkaline earth aluminosilicates, e.g. cordierite or anorthite
• CPC Class Codes: C04B 35/622 Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
• CPC Class Codes: C04B 35/6263 characterised by their solids loadings, i.e. the percentage of solids
• CPC Class Codes: C04B 35/6269 Curing of mixtures
• CPC Class Codes: C04B 35/632 Organic additives
• CPC Class Codes: C04B 35/6365 Cellulose or derivatives thereof
• CPC Class Codes: C04B 38/0006 Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0645 Burnable, meltable, sublimable materials

Abstract

A plasticized ceramic-forming mixture and a method for stiffening the mixture, the mixture comprising a combination of inorganic powder, one or more plasticizing organic binders, a radiation-curable monomer, a photoinitiator, and water, and the method comprising stiffening the surfaces of extruded shapes of the mixture by applying electromagnetic energy to the surfaces following extrusion.

Claims

1. A method for making a stable extruded shape of ceramic material comprising:

forming a plasticized ceramic powder mixture comprising inorganic powder, organic binder, radiation-curable monomer, photoinitiator and water;

extruding the plasticized powder mixture to provide an extruded shape; and

applying electromagnetic energy to the surface of the extruded shape to initiate curing of the monomer.

2. The method of claim 1 wherein the electromagnetic energy is ultraviolet light.

3. The method of claim 2 wherein the electromagnetic energy is applied to the surface of the extruded shape as it is extruded.

4. The method of claim 1 wherein the mixture is extruded to form a honeycomb shape.

5. The method of claim 4 wherein the honeycomb shape comprises a surrounding skin.

6. The method of claim 5 comprising further steps of drying and firing the honeycomb shape to provide a ceramic honeycomb.

7. A method for forming a ceramic article, comprising:

extruding a wet plasticized ceramic powder mixture comprising inorganic powder, plasticizing organic binder, radiation-curable monomer, photoinitiator and water to provide an extruded preform for the article;

applying electromagnetic energy to the surface of the extruded preform to stiffen the surface thereof; and

drying and firing the extruded preform to produce a sintered ceramic article.

8. A plasticized ceramic powder mixture for forming a ceramic article comprising:

at least one inorganic powder;

at least one organic binder;

at least one radiation-curable monomer;

at least one photoinitiator; and

water.

9. The mixture of claim 8 wherein at least one inorganic powder is selected from the group consisting of clay, talc, alumina, silica, titania, alkali and alkaline earth oxides, cordierite, aluminum titanate, mullite, silicon carbide, silicon nitride, ZrO₂, ZnO, B₂O₃, La₂O₃, and P₂O₅.

10. The mixture of claim 8 wherein at least one organic binder comprises a cellulose derivative.

11. The mixture of claim 8 wherein at least one radiation-curable monomer contains one or more ethylenically unsaturated groups.

12. The mixture of claim 8 wherein at least one photoinitiator is selected from the group consisting of:

hydroxycyclohexylphenylketone;

hydroxymethylphenylpropanone;

dimethoxyphenylactophenone;

2-methyl-1-[4-(methyl thio)-phenyl]-2-morpholinopropanone-1;

1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one;

1-(4-dodecyl-phenyl)-2-hydroxy-2-methylpropan-1-one;

4-(2-hydroxyethoxy)phenyl-2(2-hydroxy-2-propyl)ketone;

diethoxyphenyl acetophenone;

2-hydroxy-2-methyl-1-phenyl-propan-1-one;

2,4,6-trimethylbenzoyl diphenylphosphine oxide;

ethyl-2,4,6-trimethylbenzoyl phenylphosphinate;

(2,6-dimethoxy benzoyl)-2,4,4 trimethylpentylphosphine oxide;

bis(2,6-dimethoxybenzoyl)2,4,4′

-trimethylpentyl)phosphine oxide;

2-hydroxy-2-methyl-1-phenyl-propan-1-one;

(2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone);

benzophenone;

2,4 phosphine oxide;

triaryl sulfonium hexafluoroantimonate salts);

triaryl sulfonium hexafluorophosphate salts

diaryliodonium hexafluoroantimonate; and

bis(2,4-cyclopentadien-1-yl)-bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium.

13. The mixture of claim 8 wherein at least one photoinitiator is selected from the groups consisting of ketonic and phosphine-oxide based initiators.

14. The mixture of claim 8 wherein at least one photoinitiator is Bis(2,6-dimethoxybenzoyl)2,4,4-trimethyl-phosphine oxide or 1-Hydroxycyclohexyl phenyl ketone.