US3637545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing methyl methacrylate polymers
Assignee: PLASTUGIL PLASTIQUES ET ELASTO
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Filing: 1969-01-03
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Granted: 1972-01-25
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Expires: 1989-01-03
Abstract
Abstract POLYMERS OF METHYL METHACRYLATE, OPTIONALLY CONTAINING A MINOR PROPORTION OF MODIFYING AGENT, ARE PREPARED BY CONTINUOUS MASS POLYMERIZATION IN THE PRESENCE OF AN INITIATOR AND A MOLECULAR WEIGHT REGULATOR, THE REACTION MIXTURE BEING PASSED IN A LAMELLAR FLOW BETWEEN DIATHERMIC WALLS AT A CONSTANT TEMPERATURE OF 145-165*C. AND POLYMERIZED TO A CONVERSION RATE OF 40-60%. THE MIXTURE THUS OBTAINED IS FLASH DEVOLATILIZED ABOVE 200%C. TO RECOVER THE POLYMER.
Inventors
- 👤 Ernest Fivel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:02
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/10; C08F20/12; C08F2/00; C08F2/02; C08F20/14
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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |