US3829409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Block homopolymers of 1,3-butadiene and process for preparing them
Assignee: Huels AG
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Filing: 1972-11-27
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Granted: 1974-08-13
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Expires: 1992-11-27
Abstract
Abstract BLOCK HOMOPOLUMERS OF 1,3-BUTADIENE HAVING A FIRST BLOCK WITH NONUFORM VINYL GROUP DISTRIBUTION AND A FURTHER BLOCK HAVING A UNIFORM VINYL GROUP DISTRIBUTION IN A MOLE RATIO OF 20:80 TO 95:5 RESPECTIVELY AND AN AVERAGE VINYL GROUP CONTENT OF 15-75%, PREFERABLY 2050%, ARE PREPARED BY ADIABATIC SOLLVENT POLYMERIZATION AT AN ASCENDING TEMPERATURE IN THE PRESENCE OF A CATALYST SYSTEM COMPRISING AN ORGANOLITHIUM COMPOUND AND A LEWIS BASE. THE POLYMERS HAVE IMPROVED PROCESSING PROPERTIES.
Inventors
- 👤 N Sommer
- 👤 K Nordsiek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:00
CPC Classifications
C; C08; C08F; C08F136/00; C08F136/02; C08F136/04; C08F136/06
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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |