Patent US3706775A successfully refreshed from Google Patents.
US3706775A
Expired / Lapsed
US
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Method of preparing high molecular weight linear organopolysiloxanes
Assignee: Wacker Chemie AG
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Filing: 1970-12-17
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Granted: 1972-12-19
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Expires: 1990-12-17
Abstract
Abstract HIGH MOLECULAR WEIGHT COPOLYMERIC DIORGANOPOLYSILOXANES CONSISTING ESSENTIALLY OF DIPHENYLSILOXANE AND DIMETHYLSILOXCANE UNITS ARE PREPARED BY ALKALINE HYDROLYSIS AND CONDENSATION OF A MIXTURE OF 4 TO 70 MOL PERCENT (C6H5)2SICL2, 29 TO 96 MOL PERCENT (CH2)2SICL2 AND UP TO 1 MOL PERCENT OF OTHER CHLOROSILANES, EMPLOYING A SOLUTION OF 3 TO 30 PERCENT BY WEIGHT OF ALKALI METAL HYDROXIDE IN WATER AS THE HYDROLYSIS MEDIUM, SEPARATING THE HYDROLYSATES FROM THE AQUEOUS MEDIUM, AND THEREAFTER FURTHER CONDENSING AND EQUILIBRIZING THE HYDROLYSATES EMPLOYING PHOSPHOROUS-NITROGEN COMPOUNDS AS CATALYSTS.
Inventors
- 👤 Siegfried Nitzsche
- 👤 Jurgen Burkhardt
- 👤 Karl-Heinrich Wegehaupt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:58
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06
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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |