Patent US2533525A successfully refreshed from Google Patents.
US2533525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization of styrene employing phthalimide as catalyst
Assignee: IRVING L RABB
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Filing: 1947-03-17
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Granted: 1950-12-12
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Expires: 1967-03-17
Abstract
No abstract record available.
Inventors
- 👤 Francis H Snyder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:07
CPC Classifications
C; C08; C08F; C08F12/00; C08F12/02; C08F12/04; C08F12/06; C08F12/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
26 words
A METHOD OF PRODUCING POLYSTYRENE WHICH COMPRISES, POLYMERIZING STYRENE MONOMER, FREE FROM INHIBITORS, AT ELEVATED TEMPERATURE IN THE PRESENCE OF ABOUT 0.11% BY WEIGHT OF PHTHALIMIDE.
Claim 2
Independent Claim
26 words
A METHOD OF PRODUCING POLYSTYRENE WHICH COMPRISES, POLYMERIZING STYRENE MONOMER, FREE FROM INHIBITORS, AT ELEVATED TEMPERATURE IN THE PRESENCE OF ABOUT 0.11% BY WEIGHT OF PHTHALIMIDE.
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) | 1953-12-11 | 1954-06-12 | 1954-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-12-11 | 1958-06-12 | 1958-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-12-11 | 1962-06-12 | 1962-12-12 | $7700.00 | Window Closed / Lapsed |