US3679355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving polyacrylonitrile fiber by peeling off the fiber surface with solvents
Assignee: Asahi Kasei Corp
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Filing: 1968-10-10
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Granted: 1972-07-25
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Expires: 1988-10-10
Abstract
Abstract AN ACRYLIC FIBER ARTICLE IS IMPROVED BY TREATING IT WITH A SOLUTION OF A SOLVENT HAVING A CONCENTRATION HIGHER THAN THAT AT WHICH THE SOLUTION BEGINS TO DISSOLVE THE FIBER AND LOWER THAN THAT AT WHICH THE SWELLING VELOCITY OF THE SOLUTION ON THE FIBER SURFACE IS EQUAL TO THE DISPERSING VELOCITY OF THE SURFACE OF THE SWELLED LAYER TO PEEL THE FIBER. EXAMPLES OF SUCH SOLVENT ARE DIMETHYLFORMAMIDE, DIMETHYLACETAMIDE, DIMETHYLSULFOXIDE, SODIUM THIOCYANATE, ZINC CHLORIDE, SULFURIC ACID, NITRIC ACID, ETC.
Inventors
- 👤 Hiroyuki Yamaguchi
- 👤 Katsuyoshi Tuji
- 👤 Kenji Maki
- 👤 Isoo Shimonishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:44
CPC Classifications
D; D06; D06M; D06M11/00; D06M11/51; D06M11/55
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |