US3769381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of microporous sheets
Assignee: Bayer AG
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Filing: 1971-07-26
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Granted: 1973-10-30
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Expires: 1991-07-26
Abstract
Abstract MICROPOROUS SHEETS ARE PREPARED BY REACTING AN NCO TERMINATED PREPOLYMER WITH A DISECONDARY DIAMINE IN AN INERT SUBSTANCE THAT DISSOLVES THE REACTANTS BUT CAUSES ONLY SWELLING OF THE PRODUCT THEREOF AND DRYING THE DISPERSIONS THUS FORMED TO FORM MICROPOROUS FOILS.
Inventors
- 👤 K Konig
- 👤 H Traubel
- 👤 A Reischl
- 👤 B Zorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:41
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C07; C07C; C07C317/00; C07C317/16; C07C317/22; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/28; C08G18/30; C08G18/38; C08G18/3855; C08G18/3863; C08G18/3865; C08G18/3872; C08G63/00; C08G63/68; C08G63/688; C08G63/6884; C08G63/6886; C08J2375/00; C08J2375/04
Claims Analysis
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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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |