US3575892A
Expired / Lapsed
US
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Liquid butane process for preparing foamable beads
Assignee: Dart Industries Inc
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Filing: 1968-02-09
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Granted: 1971-04-20
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Expires: 1988-02-09
Abstract
Abstract THE PROCESS COMPRISES IMPREGNATING BEADS OF A POLYMER SUCH AS POLYSTYRENE IN A NON-AQUEOUS ENVIRONMENT WITH LIQUEFIED BUTANE AT CONDITIONS SUFFICIENT TO MAINTAIN THE BUTANE IN ITS LIQUEFIED STATE, REMOVING THE EXCESS BUTANE FROM THE IMPREGNATED BEADS AND RECOVERING THE FOAMABLE BEADS.
Inventors
- 👤 Michael Erchak Jr
- 👤 Philip L Mercier
- 👤 Kenneth W Doak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:13
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/18; Y; Y10; Y10S; Y10S264/00; Y10S264/05
Claims Analysis
Total Claims: 0
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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) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |