US3650992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for impregnating polymer beads with a blowing agent
Assignee: Cupples Container Co
•
Filing: 1970-09-15
•
Granted: 1972-03-21
•
Expires: 1990-09-15
Abstract
Abstract PARTICULATE POLYMERIC MATERIAL, ESPECIALLY POLYSTYRENE, IS IMPREGNATED WITH A BLOWING AGENT BY SUSPENDING THE PARTICULATE POLYMERIC MATERIAL IN A SUS PENSION SYSTEM COMPRISING ETHYLENE GLYCOL AND WATER, INTRODUCING A BLOWING AGENT, E.G., PENTANE, AND MAINTAINING UNDER CONDITIONS OF ELEVATED TEMPERATURE AND PRESSURE.
Inventors
- 👤 Edward J Schwoegler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:02
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/18
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |