US3355418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilization of methyl methacrylate and copolymers against discoloration with organic phosphites
Assignee: Wyeth Holdings LLC
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Filing: 1964-12-23
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Granted: 1967-11-28
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Expires: 1984-12-23
Abstract
No abstract record available.
Inventors
- 👤 Oldsberg Lars Ove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:28
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/52; C08K5/524
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
IN A METHOD FOR THE PRODUCTION OF POLYMERS OF METHYL METHACRYLATE CONTAINING AT LEAST 85% BY WEIGHT, OF METHYL METHACRYLATE AND UP TO 15%, BY WEIGHT, OF A DIFFERENT ACRYLATE, WHEREIN AN AQUEOUS SUSPENSION OF THE METHACRYLATE IS FORMED, THE SUSPENSION IS HEATED TO AT LEAST ABOUT 60* C. IN THE PRESENCE OF A FREE-RADICAL GENERATING CATALYST AND THE RESULTANT POLYMER IS RECOVERED AND EXTRUDED INTO PELLETS, THE IMPROVEMENT WHICH COMPRISES ADDING THERETO, PRIOR TO EXTRUSION, 0.05% TO ABOUT 0.5% BY WEIGHT, BASED ON THE WEIGHT OF THE POLYMER, OF TRIDECYL PHOSPHITE.
Claim 2
Dependent Claim
92 words
IN A METHOD FOR THE PRODUCTION OF POLYMERS OF METHYL METHACRYLATE CONTAINING AT LEAST 85% BY WEIGHT, OF METHYL METHACRYLATE AND UP TO 15%, BY WEIGHT, OF A DIFFERENT ACRYLATE, WHEREIN AN AQUEOUS SUSPENSION OF THE METHACRYLATE IS FORMED, THE SUSPENSION IS HEATED TO AT LEAST ABOUT 60* C. IN THE PRESENCE OF A FREE-RADICAL GENERATING CATALYST AND THE RESULTANT POLYMER IS RECOVERED AND EXTRUDED INTO PELLETS, THE IMPROVEMENT WHICH COMPRISES ADDING THERETO, PRIOR TO EXTRUSION, 0.05% TO ABOUT 0.5% BY WEIGHT, BASED ON THE WEIGHT OF THE POLYMER, OF TRIDECYL PHOSPHITE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-11-27 | 1971-05-29 | 1971-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-11-27 | 1975-05-29 | 1975-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-11-27 | 1979-05-29 | 1979-11-28 | $7700.00 | Window Closed / Lapsed |