Patent US3816717A successfully refreshed from Google Patents.
US3558570A
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Telomers of styrene and maleic acid anhydride and process for preparing them
Assignee: Hoechst AG
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Filing: 1969-08-25
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Granted: 1971-01-26
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Expires: 1989-08-25
Abstract
Abstract A PROCESS FOR PREPARING TELOMERS OF STYRENE AND MALEIC ACID ANHYDRIDE OF A MOLECULAR WEIGHT OF LESS THAN 2500 ID DISCLOSED. POLYMERIZATION IS EFFECTED AT A TEMPERATURE OF 160*C. TO 270*C. IN THE PRESENCE OF A R ADICAL-FORMING CATALYST AND A CHAIN-TERMINATING SOLVENT WHICH MAY BE BENZENE OR A BENZENE SUBSTITUTED ONLY BY ONE OR MORE METHYL GROUPS. THE POLYMERIZATION IS PREFERABLY CARRIED OUT AT AN ELEVATED PRESSURE.
Inventors
- 👤 Helmut Rinno
- 👤 Gerhard Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:59
CPC Classifications
C; C08; C08F; C08F222/00; C08F222/04; C08F222/06; C08F222/08; C07; C07C; C07C57/00; C07C57/30; C07C57/42; C08F22/00; C08F22/04
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |