Patent US3644587A successfully refreshed from Google Patents.
US3644587A
Expired / Lapsed
US
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Chemically controlling grating and rubber particle size in manufacture of high impact polystyrene using a 2-step process
Assignee: Mobil Oil AS
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Filing: 1969-04-03
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Granted: 1972-02-22
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Expires: 1989-04-03
Abstract
Abstract HIGH IMPACT POLYSTYRENE IS PRODUCED BY FREE RADICAL CATALYTIC BULK PREPOLYMERIZATION OF A SOLUTION OF A RUBBER AND STYRENE FOLLOWED BY SUSPENSION POLYMERIZATION. POLYMERS HAVING IMPROVED MECHANICAL AND REHOLOGICAL PROPERTIES ARE PRODUCED BY USING IN THE BULK STAGE, AN AZO INITIATOR DURING THE PHASE INVERSION STAGE AND ADDING A PEROXIDE INITIATOR JUST BEFORE THE INVERSION IS COMPLETED OR THEREAFTER.
Inventors
- 👤 Arne Finberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:20
CPC Classifications
C; C08; C08F; C08F279/00; C08F279/02
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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |