US3637541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polyetherurethane foam employing polyoxyalkylene-polysiloxane block polymers as surfactants
Assignee: Evonik Operations GmbH
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Filing: 1969-02-20
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Granted: 1972-01-25
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Expires: 1989-02-20
Abstract
Abstract IN A FOAMING PROCESS FOR PRODUCING POLYURETHANE FOAM IN WHICH THE FOAMING IS PERFORMED IN THE PRESENCE OF POLYOXYALKYLENE-POLYSILOXANE MIXED BLOCK POLYMERS, THE INVENTION PROPOSES THAT THE POLYOXYALKYLENE BLOCK SHOULD CONSIST OF TWO SEPARATE MOIETIES, OF WHICH THE FIRST CONSTITUTES ABOUT 25-70% BY WEIGHT AND HAS AN AVERAGE MOLECULAR WEIGHT OF ABOUT 1600-4000. 20-100% BY WEIGHT OF THE BLOCK BEING CONSTITUTED BY ETHYLENE OXIDE. THE SECOND POLYOXYALKYLENE MOIETY CONSTIUTES 30-75% BY WEIGHT OF THE BLOCK AND HAS AN AVERAGE MOLECULAR WEIGHT OF 400-1200, THE ETHYLENE OXIDE CONTENT OF THE BLOCK BEING BETWEEN ABOUT 65-100% BY WEIGHT.
Inventors
- 👤 Gerd Rossmy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:24
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J2375/00; C08J2375/04; C08J2375/08; C08J2483/00
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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |