Patent JPH0457860A successfully refreshed from Google Patents.
US3781391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing acrylic hollow fibers
Assignee: Wyeth Holdings LLC
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Filing: 1972-07-25
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Granted: 1973-12-25
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Expires: 1992-07-25
Abstract
Abstract THE FORMATION OF ACRYLIC FIBERS WITH VOID SPACES THEREIN BY WET SPINNING EMPLOYING AQUEOUS THIOCYANATE SALTS AS BOTH POLYMER SOLVENT AND FIBER COAGULANT BY DISPERSING SELECTED VOLATILE LIQUIDS IN THE SPIN DOPE AT A CONCENTRATION OF 25-100 WEIGHT PERCENT BASED ON THE WEIGHT OF POLYMER THEREIN, (A) SPINNING THE SPIN DOPE INTO THE COAGULANT MAINTAINED AT LESS THAN ABOUT 20*C., (B) WASHING THE COAGULATED WET GEL FIBERS AT A TEMPERATURE BELOW ABOUT 40*C. AND (C) THEREAFTER PASSING THE FIBERS THROUGH BOILING WATER OR WATER VAPOR PRIOR TO OR IN CONJUNCTION WITH HOT-DRAWING SO AS TO VOLATILIZE THE VOLATILE LIQUID AND OBTAIN VOID SPACES WITHIN THE FIBERS.
Inventors
- 👤 K Shimoda
- 👤 K Kuratani
- 👤 A Sugiura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:57
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; D01D5/247; D01F; D01F6/00; D01F6/02; D01F6/18; D01F6/28; D01F6/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |