US5232772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density carbonized composite foams
Assignee: United States Department of Energy
•
Filing: 1991-08-19
•
Granted: 1993-08-03
•
Expires: 2011-08-19
Abstract
Abstract A carbonized composite foam having a density less than about 50 mg/cm 3 and individual cell sizes no greater than about 1 μm in diameter is described, and the process of making it.
Inventors
- 👤 Fung-Ming Kong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:49
CPC Classifications
G; G21; G21B; G21B1/00; G21B1/11; G21B1/19; C; C04; C04B; C04B38/00; C04B38/0022; G21C; G21C3/00; Y; Y02; Y02E; Y02E30/00; Y02E30/10; Y02E30/30; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249967; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A carbonized composite foam which has two cellular structures, comprising: a first cellular structure formed from the polymerization of a monomer, and a second cellular structure formed from a high-carbon-yield prepolymer which occupies the cells of the first cellular structure, whereby the second cellular structure has cell diameters smaller than the first cellular structure, producing a bimodal cell size distribution; and wherein the second cellular structure has cell diameters less than about 1 micron, wherein the composite foam has a density less than about 50 mg/cm 3 , and wherein the first and second cellular structures are carbonized.
Claim 2
Dependent Claim
98 words
A carbonized composite foam which has two cellular structures, comprising: a first cellular structure formed from the polymerization of a monomer, and a second cellular structure formed from a high-carbon-yield prepolymer which occupies the cells of the first cellular structure, whereby the second cellular structure has cell diameters smaller than the first cellular structure, producing a bimodal cell size distribution; and wherein the second cellular structure has cell diameters less than about 1 micron, wherein the composite foam has a density less than about 50 mg/cm 3 , and wherein the first and second cellular structures are carbonized.
Claim 3
Dependent Claim
23 words
The composite foam as recited in claim 1, wherein the monomer is selected from the group consisting of styrene, substituted styrenes, and acrylics.
Claim 4
Dependent Claim
25 words
The composite foam as recited in claim 2, wherein the monomer is selected from the group consisting of styrene, butylstyrene, butyl methacrylate, and ethyl methacrylate.
Claim 5
Dependent Claim
26 words
The composite foam as recited in claim 1, wherein the high-carbon-yield prepolymer is selected from the group consisting of phenolaldehydes, acrylonitrile, furfuryl alcohol, and vinyl alcohol.
Claim 6
Dependent Claim
40 words
The composite foam as recited in claim 4, wherein the prepolymer is a phenol-aldehyde, and the phenol is selected from the group consisting of resorcinol, monohydric phenols, polyhydric phenols, pyrocatechol, hydroquinone, alkyl substituted phenols, polynuclear monohydric phenols, polynuclear polyhydric phenols.
Claim 7
Dependent Claim
24 words
The composite foam as recited in claim 5, wherein the aldehyde is selected from the group consisting of formaldehyde, meta-aldehyde, para-aldehyde, acetaldehyde, and benzaldehyde.
Claim 8
Dependent Claim
25 words
The composite foam as recited in claim 1, wherein the prepolymer is a phenol-aldehyde, and wherein the phenol is resorcinol and the aldehyde is formaldehyde.
Claim 9
Dependent Claim
18 words
The composite foam as recited in claim 1, wherein the composite foam is formed into a hollow sphere.
Claim 10
Dependent Claim
16 words
The composite foam as recited in claim 8, wherein a non-porous protective membrane surrounds the sphere.
Claim 11
Dependent Claim
17 words
The composite foam as recited in claim 9, wherein the membrane is formed of a thermoplastic polymer.
Claim 12
Dependent Claim
24 words
The composite foam as recited in claim 10, wherein the thermoplastic polymer is selected from the group consisting of polyvinyl alcohol, polyethylene, and polypropylene.
References Cited (Backward Citations)
US3859421A
Cited
US3874548A
Cited
US4775655A
Cited
US4693938A
Cited
US4806290A
Cited
US4832881A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-02 | 1997-02-01 | 1997-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-02 | 2001-02-01 | 2001-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-02 | 2005-02-01 | 2005-08-03 | $7700.00 | Window Closed / Lapsed |