Patent US4207408A successfully refreshed from Google Patents.
US4207408A
Expired / Lapsed
US
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High tenacity phenolic resin fibers
Assignee: Unifrax I LLC
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Filing: 1978-05-22
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Granted: 1980-06-10
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Expires: 1998-05-22
Abstract
Abstract Infusible cured phenolic resin fibers of the present invention have a birefringence of at least 2x10-3 with the x-ray diffraction pattern of the fibers showing an amorphous halo. The tenacity of infusible cured phenolic resin fibers is significantly increased by subjecting the fibers to sufficient longitudinal tension as to cause at least about 30% elongation of the fibers. The Young's modulus of elasticity of the fibers is also significantly increased thereby. Preferably the resulting stretched infusible cured phenolic resin fibers have a tenacity of at least about 4 g./den.
Inventors
- 👤 James Economy
- 👤 Francis J. Frechette
- 👤 Luis C. Wohrer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:02
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/58; D01F6/76
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
41 words
An infusible cured phenolic resin fiber having a birefringence of at least 2×10 -3 with an x-ray diffraction pattern of the fibers showing an amorphous halo, wherein at least about 50% of the phenolic hydroxyl groups of said resin are blocked.
Claim 2
Dependent Claim
41 words
An infusible cured phenolic resin fiber having a birefringence of at least 2×10 -3 with an x-ray diffraction pattern of the fibers showing an amorphous halo, wherein at least about 50% of the phenolic hydroxyl groups of said resin are blocked.
Claim 3
Dependent Claim
17 words
A fiber as set forth in claim 1 having a birefringence of at least 4×10 -3 .
Claim 4
Dependent Claim
17 words
A fiber as set forth in claim 2 having a birefringence of at least 6×10 -3 .
Claim 5
Dependent Claim
17 words
A fiber as set forth in claim 1 wherein said cured phenolic resin is a cured novolac.
Claim 6
Dependent Claim
38 words
A fiber as set forth in claim 1 wherein said fiber has been subjected to tension to cause at least about 30% permanent elongation at a temperature in the range from about 100° C. to about 300° C.
Claim 7
Dependent Claim
26 words
A fiber as set forth in claim 1 wherein said fiber is subjected to said tension while said fiber is swelled by a polar organic liquid.
Claim 8
Dependent Claim
23 words
A fiber as set forth in claim 1 comprising a cured phenolic resin fiber having a tenacity of at least about 4 g./den.
References Cited (Backward Citations)
US2101642A
Cited
US2091965A
Cited
US2212509A
Cited
US2376511A
Cited
US3088794A
Cited
US3650102A
Cited
US3651199A
Cited
US3848044A
Cited
US3716521A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |