Patent US2621171A successfully refreshed from Google Patents.
US2621171A
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Process for polymerizing alpha-methyl styrene
Assignee: Dow Chemical Co
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Filing: 1949-10-31
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Granted: 1952-12-09
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Expires: 1969-10-31
Abstract
No abstract record available.
Inventors
- 👤 Giffin D Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:32
CPC Classifications
C; C08; C08F; C08F112/00; C08F112/02; C08F112/04; C08F112/06; C08F112/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
IN A PROCESS FOR POLYMERIZING ALPHA-METHYL STYRENE TO FORM A SOLID POLYMER HAVING A MOLECULAR WEIGHT CORRESPONDING TO AN INTRINSIC VISCOSITY IN TOLUENE GREATER THAN 0.4, THE IMPROVEMENT WHICH CONSISTS IN POLYMERIZING THE ALPHA-METHYL STYRENE AT A TEMPERATURE BETWEEN 0* AND 30* C. WHILE IN ADMIXTURE WITH FINELY DIVIDED METALLIC SODIUM AND IN THE SUBSTANTIAL ABSENCE OF AN INERT LIQUID MEDIUM.
Claim 2
Dependent Claim
61 words
IN A PROCESS FOR POLYMERIZING ALPHA-METHYL STYRENE TO FORM A SOLID POLYMER HAVING A MOLECULAR WEIGHT CORRESPONDING TO AN INTRINSIC VISCOSITY IN TOLUENE GREATER THAN 0.4, THE IMPROVEMENT WHICH CONSISTS IN POLYMERIZING THE ALPHA-METHYL STYRENE AT A TEMPERATURE BETWEEN 0* AND 30* C. WHILE IN ADMIXTURE WITH FINELY DIVIDED METALLIC SODIUM AND IN THE SUBSTANTIAL ABSENCE OF AN INERT LIQUID MEDIUM.
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) | 1955-12-09 | 1956-06-09 | 1956-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-09 | 1960-06-09 | 1960-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-09 | 1964-06-09 | 1964-12-09 | $7700.00 | Window Closed / Lapsed |