US3682844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expandable polystyrene and method for producing same
Assignee: Cupples Container Co
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Filing: 1970-09-29
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Granted: 1972-08-08
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Expires: 1990-09-29
Abstract
Abstract EXPANDABLE POLYSTYRENE PARTICLES HAVING 0.5-6% BY WEIGHT ETHYLENE-VINYL ACETATE COPOLYMER DISTRIBUTED THROUGH EACH BEAD ARE PREPARED BY DISPERSING THE COPOLYMER IN FINELY DIVIDED FORM THROUGH LIQUID STYRENE MONOMER AND HEATING WITH AGITATION AT AT LEAST 60*C., DISPERSING THE RESULTING DISPERSION IN AN AQUEOUS SUSPENSION MEDIUM, AND FORMING THE PARTICLES BY SUSPENSION POLYMERIZATION. THE PARTICLES HAVE IMPROVED FUSION CHARACTERISTICS MAKING IT POSSIBLE TO PRODUCE MOLDED, FOAMED ARTICLES THEREFROM IN A SHORTER MOLDING TIME. THE MOLDED ARTICLES HAVE AN IMPROVED AND DISTINCTIVE SURFACE APPEARANCE AS COMPARED WITH ARTICLES MOLDED FROM UNMODIFIED POLYSTYRENE PARTICLES.
Inventors
- 👤 Edward J Schwoegler
- 👤 Clifford P Ronden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:14
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/20; C08F; C08F255/00; C08F255/02; C08F255/026; C08F263/00; C08F263/02; C08F263/04
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |