US3598887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of block copolymers
Assignee: Polysar Ltd
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Filing: 1966-12-23
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Granted: 1971-08-10
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Expires: 1986-12-23
Abstract
Abstract A CHEMICAL PROCESS FOR MAKING BLOCK COPOLYMERS, WHICH INCLUDES THE STEPS OF PREPARING A LIVING BLOCK COPOLYMER BY ANIONIC POLYMERIZATION, E.G. USING A LITHIUM HYDROCARBYL AS INITIATOR, AND REACTING THE LIVING BLOCK COPOLYMER WITH EITHER CARBON DIOXIDE, CARBONYL SULPHIDE OR CARBON DISULPHIDE TO COUPLE THE BLOCK COPOLYMER MOLECULES THROUGH THEIR LIVE ENDS.
Inventors
- 👤 Jules Darcy
- 👤 Robert C Mackenzie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:52
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/02; C08F297/04; C08F297/044; C08G; C08G81/00; C08G81/02; C08G81/021; C08G81/022
Claims Analysis
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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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |