US3640955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear polyurethane of di- or tri-nuclear n n'-dialkyldiamines and di- or tri-nuclear dihydroxyl compounds
Assignee: Bayer AG
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Filing: 1970-07-22
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Granted: 1972-02-08
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Expires: 1990-07-22
Abstract
Abstract HIGH MOLECULAR WEIGHT POLYURETHANES HAVING EXCELLENT THERMAL STABILITY BASED ON CONDENSING DI- OR TRINUCLEAR N,N''-DIALKYLDIAMINES IN WHICH THE NITROGEN IS AROMATICALLY LINKED WITH DI- OR TRI-NUCLEAR DIHYDROXYL COMPOUNDS AND BIFUNCTIONAL CARBONIC ACID DERIVATIVES, OR BY CONDENSING BIS-MONOCARBONIC ACID DERIVATIVES OF DI- OR TRI-NUCLEAR N,N''-DIALKYLDIAMINES WITH DI- OR TRI-NUCLEAR AROMATIC DIHYDROXYL COMPOUNDS OR BY CONDENSING BIS-MONOCARBONIC ACID DERIVATIVES OF DI- OR TRI-NUCLEAR AROMATIC DIHYDROXYL COMPOUNDS WITH DI- OR TRI-NUCLEAR N,N''-DIALKYLDIAMINES.
Inventors
- 👤 Heinrich Krimm
- 👤 Hermann Schnell
- 👤 Gunther Lenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:01
CPC Classifications
C; C08; C08L; C08L75/00
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |