US4447565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and composition for molding low density desiccant syntactic foam articles
Assignee: United States Department of Energy
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Filing: 1981-12-07
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Granted: 1984-05-08
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Expires: 2001-12-07
Abstract
Abstract A method and a composition are provided for molding low density desiccant syntactic foam articles. A low density molded desiccant article may be made as a syntactic foam by blending a thermosetting resin, microspheres and molecular sieve desiccant powder, molding and curing. Such articles have densities of 0.2-0.9 g/cc, moisture capacities of 1-12% by weight, and can serve as light weight structural supports.
Inventors
- 👤 James W. Lula
- 👤 James R. Schicker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:41
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0066; C08J9/32; Y; Y10; Y10S; Y10S264/00; Y10S264/06; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249971; Y10T428/249974
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
153 words
A process for molding to size a desiccant syntactic foam article having a density of 0.2-0.9 g/cc and a moisture capacity of 1-12% by weight, comprising the steps of: (a) charging a mold with a powdery mixture of an activated molecular sieve desiccant, microspheres and a thermosetting resin, the amount of the desiccant being sufficient to provide the required moisture capacity, and the amounts of the microspheres and resin being such that the microspheres/desiccant volume fraction exceeds the packing factor by an amount sufficient to substantially avoid shrinkage without causing excessively high molding pressures; (b) covering the mold and heating the covered mold to a temperature and for an amount of time sufficient to melt the resin; and (c) tightly closing the mold and heating the closed mold to a temperature and for an amount of time sufficient to cure the resin, and removing the resultant desiccant syntactic foam article from the mold.
Claim 2
Dependent Claim
153 words
A process for molding to size a desiccant syntactic foam article having a density of 0.2-0.9 g/cc and a moisture capacity of 1-12% by weight, comprising the steps of: (a) charging a mold with a powdery mixture of an activated molecular sieve desiccant, microspheres and a thermosetting resin, the amount of the desiccant being sufficient to provide the required moisture capacity, and the amounts of the microspheres and resin being such that the microspheres/desiccant volume fraction exceeds the packing factor by an amount sufficient to substantially avoid shrinkage without causing excessively high molding pressures; (b) covering the mold and heating the covered mold to a temperature and for an amount of time sufficient to melt the resin; and (c) tightly closing the mold and heating the closed mold to a temperature and for an amount of time sufficient to cure the resin, and removing the resultant desiccant syntactic foam article from the mold.
Claim 3
Dependent Claim
11 words
The process of claim 1, wherein the microspheres are glass microbubbles.
Claim 4
Dependent Claim
21 words
The process of claim 2, wherein the glass microbubbles have diameters of 10-150 μm and a bulk density of 0.16-0.38 g/cc.
Claim 5
Dependent Claim
16 words
The process of claim 3, wherein the glass microbubbles have a bulk density of 0.18-0.22 g/cc.
Claim 6
Dependent Claim
23 words
The process of claim 1, wherein the thermosetting resin is a polybenzimidazole resin, a polyphenylene resin, a phenolic resin or a polyimide resin.
Claim 7
Dependent Claim
12 words
The process of claim 5, wherein the resin is a polyimide resin.
Claim 8
Dependent Claim
23 words
The process of claim 1, wherein the desiccant is Type 3 A molecular sieve having a nominal pore size of about 0.3 nm.
Claim 9
Dependent Claim
19 words
The process of claim 1, wherein the microspheres/desiccant volume fraction exceeds the packing factor by up to about 25%.
Claim 10
Dependent Claim
17 words
The process of claim 8, wherein the microspheres/desiccant volume fraction exceeds the packing factor by about 5-15%.
Claim 11
Dependent Claim
26 words
A desiccant syntactic foam article having a density of 0.2-0.9 g/cc and a moisture capacity of 1-12% by weight, produced by the process of claim 1.
Claim 12
Dependent Claim
18 words
The desiccant syntactic foam article of claim 10, having a compressive strength of at least about 750 psi.
Claim 13
Dependent Claim
18 words
A desiccant syntactic foam article of claim 11, wherein the compression strength is at least about 1000 psi.
Claim 14
Dependent Claim
47 words
A desiccant syntactic foam article according to claim 1, having a density of 0.2-0.9 g/cc, a moisture capacity of 1-12% by weight, and a compressive strength of at least about 750 psi, comprising a filler of molecular sieve desiccant and microspheres, and a cured thermoset resin binder.
Claim 15
Dependent Claim
17 words
The desiccant syntactic foam article of claim 13, wherein the compressive strength is at least 1000 psi.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |