US2549538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for depolymerizing polystyrene
Assignee: Standard Oil Development Co
•
Filing: 1945-08-25
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Granted: 1951-04-17
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Expires: 1965-08-25
Abstract
No abstract record available.
Inventors
- 👤 William J Sparks
- 👤 David W Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:09
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/50; Y; Y10; Y10S; Y10S260/00; Y10S260/43
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
THE METHOD OF MODIFYING POLYSTYRENE HAVING A MOLECULAR WEIGHT ABOVE ABOUT 80,000, WHICH COMPRISES DISSOLVING SAID POLYSTYRENE IN A SOLUTION CONTAINING AN ACTIVE ALUMINUM HALIDE CATALYST DISSOLVED IN A LOWER ALKYL HALIDE OF 1 TO 2 CARBON ATOMS, MAINTAINING THE RESULTING SOLUTION AT A TEMPERATURE OF -25* C. TO 5* C. A SUFFICIENT TIME, FOR THE DISSOLVED POLYSTYRENE TO UNDERGO MODIFICATION WITH DECREASE IN ITS MOLECULAR WEIGHT TO ABOUT 30,000-70,000, AND THEREAFTER PRECIPITATING THE THUS MODIFIED POLYSTYRENE FROM THE SOLUTION.
Claim 2
Independent Claim
80 words
THE METHOD OF MODIFYING POLYSTYRENE HAVING A MOLECULAR WEIGHT ABOVE ABOUT 80,000, WHICH COMPRISES DISSOLVING SAID POLYSTYRENE IN A SOLUTION CONTAINING AN ACTIVE ALUMINUM HALIDE CATALYST DISSOLVED IN A LOWER ALKYL HALIDE OF 1 TO 2 CARBON ATOMS, MAINTAINING THE RESULTING SOLUTION AT A TEMPERATURE OF -25* C. TO 5* C. A SUFFICIENT TIME, FOR THE DISSOLVED POLYSTYRENE TO UNDERGO MODIFICATION WITH DECREASE IN ITS MOLECULAR WEIGHT TO ABOUT 30,000-70,000, AND THEREAFTER PRECIPITATING THE THUS MODIFIED POLYSTYRENE FROM THE SOLUTION.
References Cited (Backward Citations)
US1988529A
Cited
US2400129A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-16 | 1954-10-16 | 1955-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-16 | 1958-10-16 | 1959-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-16 | 1962-10-16 | 1963-04-17 | $7700.00 | Window Closed / Lapsed |