US3557255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pivalolactone-diene block copolymers and their preparation
Assignee: EIDP Inc
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Filing: 1969-03-21
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Granted: 1971-01-19
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Expires: 1989-03-21
Abstract
Abstract BLOCK COPOLYMERS OF THE ABA TYPE ARE DESCRIBED IN WHICH BOTH A UNITS ARE POLYPIVALOLACTONE, OR OPTIONALLY ONE A UNIT IS POLYSTYRENE, AND THE B UNIT IS A POLYDIENE (ISOPRENE OR BUTADIENE). THE BLOCK COPOLYMERS ARE USEFUL ELASTOMERS WHICH REQUIRE NO VULCANIZATION. WHEN THE TWO A UNITS ARE THE SAME, THE POLYDIENE UNIT IS FIRST FORMED WITH TWO "LIVING" ANIONIC GROUPS, E.G., FROM SODIUM OR LITHIUM, AND POLYPIVALOLACTONE FORMED FROM THE ENDS. WHEN POLYSTYRENE IS PRESENT, IT IS FIST FORMED WITH N-BUTYLLITHIUM, THE DIENE POLYMERIZED ON THE "LIVING END" OF THE POLYSTYRENE, AND THE POLYPIVALOLACTONE PRODUCED ON THE "LIVING END" OF THE DIENE.
Inventors
- 👤 William H Sharkey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:53
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; C08F; C08F297/00; C08F297/02
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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |