US3760054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing porous aromatic polyamide fibers
Assignee: EIDP Inc
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Filing: 1972-07-28
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Granted: 1973-09-18
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Expires: 1992-07-28
Abstract
Abstract Porous fibers of an aromatic polyamide in which the void volume for pores having pore diameters of 0.12 micron or less is greater than 0.03 cc./gm., and the void volume for pores having pore diameters of more than 0.12 micron is less than 0.02 cc./gm. Such fibers are prepared by a process wherein freshly spun fibers are drawn and extracted in one or more solvent-containing aqueous baths of specified composition and temperature, subjected to steam when the drawing step is carried out at certain conditions, and are then dried. Such fibers are dyeable without the use of superatmospheric pressures or dyeing assistants.
Inventors
- 👤 G Moulds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:09
CPC Classifications
D; D06; D06P; D06P5/00; D06P5/22; D01; D01D; D01D5/00; D01D5/12; D01D5/24; D01D5/247; D01F; D01F6/00; D01F6/58; D01F6/60; D01F6/605
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
93 words
The process of claim 1 wherein the fiber is drawn at a total draw ratio of at least 2.8:1 in a series of at least two aqueous draw baths that contain 26 to 32 percent by weight of said solvent and 6 to 9 percent by weight of said solubilizing salt, based on the weight of solution, and wherein the draw baths are heated to a temperature of between 90* to 100*C., followed by extraction of the fiber in water, and drying of the fiber with air heated to between 110* to 150*C.
Claim 2
Dependent Claim
34 words
The process of claim 2 wherein after being extracted and before being dried, the fiber is subjected to steam at a steam pressure of 10 to 55 psig. while being free from substantial tension.
Claim 3
Dependent Claim
12 words
The process of claim 3 wherein said aromatic polyamide is poly(meta-phenylene isophthalamide).
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US3227793A
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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) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |