US3644298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of fiber-forming polyamides of improved dyeability
Assignee: Glanzstoff AG
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Filing: 1969-01-13
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Granted: 1972-02-22
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Expires: 1989-01-13
Abstract
Abstract PROCESS FOR IMPROVING THE DYEABILITY OF HIGH MOLECULAR WEIGHT LINEAR FIBER-FORMING SYNTHETIC POLYAMIDES WHILE RETAINING SUFFICIENT SOLUTION VISCOSITY WHEREIN THERE IS ADDED TO THE INITIAL POLYAMIDE-FORMING MONOMERIC REACTANT, PRIOR TO OR DURING ITS CONVENTIONAL POLYCONDENSATION, (A) AN ALKYLENT DIAMINE SUCH AS HEAMETHYLENE DIAMINE AND (B) A CARBONIC ACID ESTER SUCH AS ETHYLENE CARBONATE. THE RESULTING PRODUCT HAS A MUCH HIGHER AFFINITY FOR ACID DYES WHILE AVOIDING CERTAIN DISADVANTAGES OF ADDING (A) OR (B) ALONE.
Inventors
- 👤 Klaus Gerlach
- 👤 Wolfgang Grimm
- 👤 Helmut Linhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:31
CPC Classifications
D; D06; D06P; D06P3/00; D06P3/02; D06P3/04; D06P3/24; D06P3/241; C; C08; C08G; C08G69/00; C08G69/02
Claims Analysis
Total Claims: 0
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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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |