US3661962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molecular weight control and polysiloxanes
Assignee: Wacker Chemical Corp
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Filing: 1969-05-09
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Granted: 1972-05-09
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Expires: 1989-05-09
Abstract
Abstract HEXAMETHYLDISLOXANE IS USED TO CONTROL THE MOLECULAR WEIGHT IN THE POLYMERIZATION OF CYCLIC SILOXANES WITH A BASIC CATAYST. THE ADDITION OF A PROMOTER, SUCH AS DIMETYLFORMANIDE, PERMITS EFFICIENT UTILLIZATION OF THE HEXAMETHYLDISILOXANE AND THEREBY PERMITS ACCURATE CONTROL OVER THE MOLECULAR WEIGHT OF THE POLYSILOXANE.
Inventors
- 👤 Lothar Ernst Geipel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:24
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06; C08G77/08
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |