US5286767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified agar and process for preparing modified agar for use ceramic composition to add green strength and/or improve other properties of a preform
Assignee: Pgi Northstar LLC
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Filing: 1991-03-28
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Granted: 1994-02-15
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Expires: 2011-03-28
Abstract
Abstract Novel gel-forming compositions are used in a process for molding ceramic compositions. Gel-forming compositions, such as agar, are improved with a gel-enhancing agent, e.g. polyethyleneimine. The novel gel-forming compositions improved the ceramic molding process and/or the ceramic products formed therefrom.
Inventors
- 👤 Ronald P. Rohrbach
- 👤 Julie R. Schollmeyer
- 👤 Anthony J. Fanelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:53
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/22; B22F3/225; B22F1/00; B22F1/10; B22F1/103; C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/636; B22F2998/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
53 words
A molding composition comprising powders selected from the group consisting of metal powders, ceramic powders and mixtures thereof, a gel-forming polysaccharide material, a gel-enhancing agent capable of reacting with said gel-forming material, and an oxidizing agent capable of oxidizing said gel-forming material, wherein said gel-enhancing agent is a polymer having nitrogen containing groups.
Claim 2
Dependent Claim
53 words
A molding composition comprising powders selected from the group consisting of metal powders, ceramic powders and mixtures thereof, a gel-forming polysaccharide material, a gel-enhancing agent capable of reacting with said gel-forming material, and an oxidizing agent capable of oxidizing said gel-forming material, wherein said gel-enhancing agent is a polymer having nitrogen containing groups.
Claim 3
Dependent Claim
12 words
A composition according to claim 1 wherein said gel-forming material is agar.
Claim 4
Dependent Claim
13 words
A composition of claim 1 which further comprises a solvent for gel-forming material.
Claim 5
Dependent Claim
12 words
The composition of claim 1 wherein said gel-enhancing agent is a poly(amine).
Claim 6
Dependent Claim
10 words
The composition of claim 4 further comprising an oxidizing agent.
Claim 7
Dependent Claim
17 words
The composition of claim 5 wherein the oxidizing agent is a periodate acid or metal salt thereof.
Claim 8
Dependent Claim
17 words
The composition of claim 1 wherein said oxidizing agent is a periodate acid or metal salt thereof.
Claim 9
Dependent Claim
135 words
An injection molding process comprising the steps of a) injecting a mixture comprising (1) powders selected from the group consisting of metal powders, ceramic powders and mixtures thereof, (2) a gel-forming polysaccharide material, (3) a gel-enhancing agent capable of reacting with said gel-forming material, (4) a gel-forming material solvent, and (5) an oxidizing agent capable of oxidizing said gel-forming material; into a mold, the mixture being maintained prior to the injection step at a first temperature above the gel point of the gel-forming material, said temperature being in the range from about 70° C. to about 100° C.; and b) cooling the mixture in the mold to a second temperature below the gel point of the gel-forming material to form a self supporting article, wherein said gel-enhancing agent is a polymer having nitrogen containing groups.
Claim 10
Dependent Claim
135 words
An injection molding process comprising the steps of a) injecting a mixture comprising (1) powders selected from the group consisting of metal powders, ceramic powders and mixtures thereof, (2) a gel-forming polysaccharide material, (3) a gel-enhancing agent capable of reacting with said gel-forming material, (4) a gel-forming material solvent, and (5) an oxidizing agent capable of oxidizing said gel-forming material; into a mold, the mixture being maintained prior to the injection step at a first temperature above the gel point of the gel-forming material, said temperature being in the range from about 70° C. to about 100° C.; and b) cooling the mixture in the mold to a second temperature below the gel point of the gel-forming material to form a self supporting article, wherein said gel-enhancing agent is a polymer having nitrogen containing groups.
Claim 11
Dependent Claim
15 words
Article of manufacture produced by heating the product formed by the method of claim 8.
References Cited (Backward Citations)
US3878895A
Cited
US4273734A
Cited
US4442175A
Cited
EP0246438A2
Cited
US4734237A
Cited
JPS6310190A
Cited
US4826643A
Cited
US5047181A
Cited
US5034448A
Cited
EP0325425A2
Cited
JPH01275411A
Cited
US5089343A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-14 | 2005-08-16 | 2006-02-15 | $7700.00 | Window Closed / Lapsed |