US5360669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbon fibers
Assignee: Specialty Filaments Inc
•
Filing: 1990-06-06
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Granted: 1994-11-01
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Expires: 2010-06-06
Abstract
Abstract Microcellular carbon filaments having a specific gravity about 20-30% less than conventional carbon fibers made of the same precursor resin are formed by foaming the precursor resin during spinning. These low density microcellular carbon filaments, which may also be hollow, have improved insulation properties compared with conventional carbon fibers, they have a higher than expected strength to weight ratio and adhere in a superior fashion to a variety of matrix materials.
Inventors
- 👤 Robert L. Noland
- 👤 Timothy D. O'Brien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:05
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24124; Y10T428/249921; Y10T428/249924; Y10T428/249928; Y10T428/30; Y10T442/00; Y10T442/20; Y10T442/2008; Y10T442/2926; Y10T442/2984
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
41 words
An improved carbon fiber formed from a foamed resinous material and having a microcellular structure and a specific gravity approximately 20-30% less than a carbon fiber formed of the same precursor material and treated in the same way but not foamed.
Claim 2
Dependent Claim
41 words
An improved carbon fiber formed from a foamed resinous material and having a microcellular structure and a specific gravity approximately 20-30% less than a carbon fiber formed of the same precursor material and treated in the same way but not foamed.
Claim 3
Dependent Claim
12 words
A carbon fiber according to claim 1 having a pock-marked outer surface.
Claim 4
Dependent Claim
13 words
A carbon fiber according to claim 1 having a hollow bore extending therethrough.
Claim 5
Dependent Claim
13 words
A carbon fiber according to claim 2 having a hollow bore extending therethrough.
Claim 6
Dependent Claim
13 words
A carbon fiber according to claim 1 wherein said precursor material is pitch.
Claim 7
Dependent Claim
13 words
A carbon fiber according to claim 5 wherein said pitch is mesophase pitch.
Claim 8
Dependent Claim
16 words
A carbon fiber according to claim 5 having a specific gravity of about 1.1 to 1.3.
Claim 9
Dependent Claim
19 words
A carbon fiber according to claim 3 formed of pitch and having specific gravity of about 0.78 to 1.2.
Claim 10
Dependent Claim
57 words
In a composite material formed of a matrix material reinforced with carbon fibers, the improvement wherein said carbon fibers are formed from a foamed resinous material and have a microcellular structure and a specific gravity approximately 20-30% less than a carbon fiber formed of the same precursor material and treated in the same way but not foamed.
Claim 11
Dependent Claim
57 words
In a composite material formed of a matrix material reinforced with carbon fibers, the improvement wherein said carbon fibers are formed from a foamed resinous material and have a microcellular structure and a specific gravity approximately 20-30% less than a carbon fiber formed of the same precursor material and treated in the same way but not foamed.
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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) | 1997-10-31 | 1998-05-02 | 1998-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-31 | 2002-05-02 | 2002-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-31 | 2006-05-02 | 2006-11-01 | $7700.00 | Window Closed / Lapsed |