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US3558267A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for dyeing high-temperature-resistant polyamides and polyimides

Assignee: EIDP Inc
•
Filing: 1967-08-02
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Granted: 1971-01-26
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Expires: 1987-08-02
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Abstract

Abstract FILAMENTS OF AROMATIC POLYAMIDES AND AROMATIC POLYIMIDES THAT STRUCTURALLY WITHSTAND TEMPERATURES OF OVER 150*C. ARE DIFFICULT TO DYE BY CONVENTIONAL TECHNIQUES, BUT ARE READILY DYED AT TEMPERATURES OVER 100*C., PREFERABLY 120 TO 160*C., IN A SOLUTION OF A DYE IN A POLAR ORGANIC SOLVENT THAT CONTAINS OXYGEN IN THE MOLECULE, PREFERABLY N,N-DIALKYLCARBOXYLIC ACID AMIDES SUCH AS N,N-DIMETHYLFORMAMIDE. THE FILAMENTS CAN BE LED THROUGH A NARROW CONDUIT IN WHICH THE DYE SOLUTION IS HELD. THE FILAMENTS CAN BE MIXED WITH OTHER FILAMENTS AND FIBERS THAT ARE NOT MATERIALLY DAMAGED BY THE DYE SOLUTION, AND SUCH MIXTURES SUBJECTED TO THE DYEING TREATMENT.

Inventors

  • 👤 Bruno Wilhelm Langenfeld

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 14:38
CPC Classifications
D; D06; D06P; D06P1/00; D06P1/90; D06P1/92; D06P1/928; D06P3/00; D06P3/02; D06P3/04; D06P3/24; D06P3/241; D06P3/248; Y; Y10; Y10S; Y10S8/00; Y10S8/92; Y10S8/924

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) 1974-01-25 1974-07-27 1975-01-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-01-25 1978-07-27 1979-01-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-01-25 1982-07-27 1983-01-26 $7700.00 Window Closed / Lapsed

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