US3644567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing block copolymers from a tetrahydrofuran polymer
Assignee: 3M Co
•
Filing: 1970-06-23
•
Granted: 1972-02-22
•
Expires: 1990-06-23
Abstract
Abstract BLOCK COPOLYMERS ARE PREPARED BY POLYMERIZING A CATIONICALLY POLYMERIZABLE MONOMER WITH POLYCATIONICALLY POLYMER OF A TETRAHYDROFURAN. IN AN EXAMPLE, 10 ML. OF TETRAHYDROFURAN AND 0.5 ML. OF TRIFLUOROMETHANE SULFONIC ANHYDRIDE WERE REACTED AT ROOM TEMPERATURE TO PRODUCE A DICATIONICALLY ACTIVE POLYTETRAHYDROFURAN. ETHYLENE OXIDE WAS POLYMERIZED ONTO THE ENDS OF THE TETRAHYDROFURAN POLYMER AT ROOM TEMPERATURE, AND THE BLOCK COPOLYMER PRODUCT THEN WAS QUENCHED IN DILUTE AQUEOUS SODIUM HYDROXIDE FOR 70 HOURS AND WAS WASHED WITH WATER CONTAINING SODIUM BROMIDE.
Inventors
- 👤 Samuel Smith
- 👤 Allen J Hubin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:20
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/04; C08G65/06; C08G65/16; C08G65/20; C08G65/32; C08G65/329
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |