US2978439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the purification of polyamides
Assignee: Bayer AG
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Filing: 1958-03-13
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Granted: 1961-04-04
•
Expires: 1978-03-13
Abstract
No abstract record available.
Inventors
- 👤 Kersting Adolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:10
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/46
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
70 words
PROCESS FOR THE PURIFICATION OF CHIPS OF HIGH MOLECULAR WEIGHT POLYAMIDES SELECTED FROM THE GROUP CONSISTING OF POLY-E-AMINOCAPROIC ACID AND MIXED POLYAMIDES OF E-AMINOCAPROIC ACID WITH POLYAMIDE FORMING DIAMINES AND DICARBOXYLIC ACIDS, CONTAINING IMPURITIES SELECTED FROM THE GROUP CONSISTING OF MONOMERIC E-CAPROLACTAM AND LOW MOLECULAR WEIGHT CONDENSATION PRODUCTS THEREOF, WHICH COMPRISES WASHING SAID CHIPS WITH BOILING AQUEOUS SOLUTIONS OF HYDRAZINE, THE AMOUNT OF HYDRAZINE BEING FROM ABOUT 10-100 MG./1. SOLUTION.
Claim 2
Dependent Claim
70 words
PROCESS FOR THE PURIFICATION OF CHIPS OF HIGH MOLECULAR WEIGHT POLYAMIDES SELECTED FROM THE GROUP CONSISTING OF POLY-E-AMINOCAPROIC ACID AND MIXED POLYAMIDES OF E-AMINOCAPROIC ACID WITH POLYAMIDE FORMING DIAMINES AND DICARBOXYLIC ACIDS, CONTAINING IMPURITIES SELECTED FROM THE GROUP CONSISTING OF MONOMERIC E-CAPROLACTAM AND LOW MOLECULAR WEIGHT CONDENSATION PRODUCTS THEREOF, WHICH COMPRISES WASHING SAID CHIPS WITH BOILING AQUEOUS SOLUTIONS OF HYDRAZINE, THE AMOUNT OF HYDRAZINE BEING FROM ABOUT 10-100 MG./1. SOLUTION.
References Cited (Backward Citations)
US2735840A
Cited
US2731081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-03 | 1964-10-03 | 1965-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-03 | 1968-10-03 | 1969-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-03 | 1972-10-03 | 1973-04-04 | $7700.00 | Window Closed / Lapsed |