US3646044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precipitation copolymerization of maleic anhydride in aqueous medium
Assignee: DeSoto Inc
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Filing: 1969-05-21
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Granted: 1972-02-29
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Expires: 1989-05-21
Abstract
Abstract MALEIC COMPOUND, SUCH AS MALEIC ANHYDRIDE, AND VINYL MONOMER, SUCH AS STYRENE, ARE COPOLYMERIZED IN AQUEOUS MEDIUM CONTAINING WATER-MISCIBLE ORGANIC SOLVENT SO THAT POLYMERIZATION TAKES PLACE IN AN AQUEOUS MEDIUM TO CAUSE THE COPOLYMER TO PRECIPITATE AS IT IS FORMED. WHEN MALEIC ANHYDRIDE IS USED, IT HYDROLYZES IN THE AQUEOUS MEDIUM SO THAT THE COPOLYMER WHICH IS FORMED IS AN ACID COPOLYMER.
Inventors
- 👤 Kazys Sekmakas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:08
CPC Classifications
C; C08; C08F; C08F22/00; C08F22/04; C08F8/00
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |