US5047225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density carbonized composite foams
Assignee: United States Department of Energy
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Filing: 1990-03-14
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Granted: 1991-09-10
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Expires: 2010-03-14
Abstract
Abstract A carbonized composite foam having a density less than about 50 mg/cm3 and individual cell sizes no greater than about 1 mu m 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
2026-11-04 14:41
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; Y10S; Y10S376/00; Y10S376/916
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
A low density carbonized polystyrene-resorcinol-formaldehyde composite foam prepared by a process comprising: (A) preparing an inverse emulsion of a styrene monomer in water: (B) polymerizing said styrene monomer to produce a foam; (C) filling said foam with an aqueous resorcinol-formaldehyde solution in an amount sufficent to substantially occupy the cells of said foam; (D) curing said resorcinol-formaldehyde in said solution to form a gel; and (E) heating said resorcinol-formaldehyde gel filled polystyrene foam to a temperature sufficient to carbonize said foam, whereby a foam having a density less than about 50 mg/cm 3 and interlinked cells of a diameter no greater than about 1 μm is produced.
Claim 2
Dependent Claim
107 words
A low density carbonized polystyrene-resorcinol-formaldehyde composite foam prepared by a process comprising: (A) preparing an inverse emulsion of a styrene monomer in water: (B) polymerizing said styrene monomer to produce a foam; (C) filling said foam with an aqueous resorcinol-formaldehyde solution in an amount sufficent to substantially occupy the cells of said foam; (D) curing said resorcinol-formaldehyde in said solution to form a gel; and (E) heating said resorcinol-formaldehyde gel filled polystyrene foam to a temperature sufficient to carbonize said foam, whereby a foam having a density less than about 50 mg/cm 3 and interlinked cells of a diameter no greater than about 1 μm is produced.
Claim 3
Dependent Claim
27 words
The composite foam of claim 1 wherein said resorcinol-formaldehyde solution comprises a mixture of resorcinol and formaldehyde in about a 1:2 molar ratio in aqueous sodium carbonate.
Claim 4
Dependent Claim
41 words
The composite foam of claim 2 wherein the resorcinol to carbonate ratio by weight ranges from 35 to 300, and said sodium carbonate is present in an amount sufficient to provide a solution pH ranging from about 6 to about 7.
Claim 5
Dependent Claim
26 words
The composite foam of claim 1 wherein said styrene monomer is polymerized in step (B) by heating said emulsion to a temperature of about 50° C.
Claim 6
Dependent Claim
22 words
The composite foam of claim 1 wherein said resorcinol-formaldehyde solution is cured in step (D) at a temperature of about 90° C.
Claim 7
Dependent Claim
24 words
The composite foam of claim 1 wherein said resorcinol-formaldehyde gel filled polystyrene foam is heated to a temperature of at least about 1050° C.
Claim 8
Dependent Claim
76 words
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 prepared by: (A) polymerizing an inverse emulsion of styrene monomers, thereby producing a foam having uniform size cells; (B) filling the cells of said foam with a resorcinol-formaldehyde solution; (C) curing said resorcinol-formaldehyde solution thereby forming a gel; and (D) heating said foam to a temperature sufficiently high to carbonize it.
Claim 9
Dependent Claim
76 words
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 prepared by: (A) polymerizing an inverse emulsion of styrene monomers, thereby producing a foam having uniform size cells; (B) filling the cells of said foam with a resorcinol-formaldehyde solution; (C) curing said resorcinol-formaldehyde solution thereby forming a gel; and (D) heating said foam to a temperature sufficiently high to carbonize it.
References Cited (Backward Citations)
US3577363A
Cited
US4276246A
Cited
EP0060138A1
Cited
US4775655A
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) | 1994-09-09 | 1995-03-11 | 1995-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-09 | 1999-03-11 | 1999-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-09 | 2003-03-11 | 2003-09-10 | $7700.00 | Window Closed / Lapsed |