Patent US3794622A successfully refreshed from Google Patents.
US3794622A
Expired / Lapsed
US
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Divinyl ether-maleic anhydride copolymer
Assignee: Hercules LLC
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Filing: 1971-12-22
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Granted: 1974-02-26
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Expires: 1991-12-22
Abstract
Abstract UNIFORM SOLID CYCLIC COPOLYMERS OF DIVINYL ETHER AND MALEIC ANHYDRIDE, WATER-SOLUBLE ON HYDROLYSIS, HAVE BEEN FOUND WHICH ARE ACTIVE IN TREATING TUMORS AND VIRUSES BUT LACK THE UNDESIRABLE SIDE EFFECTS OF THE NONUNIFORM PRIOR ART COPOLYMERS. THESE COPOLYMERS ARE CHARACTERIZED BY CONTAINING DIVINYL ETHER AND MALEIC ANHYDRIDE IN A MOLE RATIO OF ABOUT 1:2, HAVING A NUMBER AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 5000 TO ABOUT 30,000 AND A MW/MN RATIO OF ABOUT 1.0 TO ABOUT 3.0.
Inventors
- 👤 D Breslow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:01
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/48; A; A61; A61P; A61P31/00; A61P31/12; A61P35/00; C08F8/46
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |