US3671542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optically anisotropic aromatic polyamide dopes
Assignee: EIDP Inc
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Filing: 1969-05-23
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Granted: 1972-06-20
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Expires: 1989-05-23
Abstract
Abstract Compositions or dopes comprising carbocyclic aromatic polyamides in suitable liquid media are prepared which are optically anisotropic (exhibit different light transmission properties in different directions in the dope). These dopes, and related isotropic dopes, are used in preparing fibers of unique internal structure (evidenced by low orientation angle and/or high sonic velocity) and exceptionally high tensile properties (e.g., initial modulus).
Inventors
- 👤 Stephanie Louise Kwolek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:10
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/58; D01F6/60; D01F6/605; C; C08; C08J; C08J3/00; C08J3/02; C08J2377/00; C08J2377/10
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
24 words
Dope of claim 1 wherein said liquid medium is concentrated (greater than about 98 percent by weight) sulfuric acid which may contain free SO3.
References Cited (Backward Citations)
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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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |