Patent US3738972A successfully refreshed from Google Patents.
US3738972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for production of styrene/acrylonitrile copolymers
Assignee: Daicel Corp
•
Filing: 1971-08-26
•
Granted: 1973-06-12
•
Expires: 1991-08-26
Abstract
Abstract SUSPENSION POLYMERIZATION OF A STYRENE-ACRYLONITRILE POLYMERIZATION MIXTURE IS CARRIED OUT WHILE ADDING STYRENE TO THE POLYMERIZATION MIXTURE UNTIL THE CONVERSION OF MONOMERS TO COPOLYMER REACHES 40 TO 70%. AN INERT GAS IS PASSED THROUGH THE POLYMERIZATION SYSTEM AFTER THE CONVERSION HAS REACHED 75 TO 85% TO REMOVE EXCESS ACRYLONITRILE, WHEREBY THERE IS OBTAINED A STYRENE-ACRYLONITRILE COPOLYMER HAVING A UNIFORM HOMOGENOUS COMPOSITION.
Inventors
- 👤 K Moriyama
- 👤 S Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:52
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08F212/10
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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |