Patent US3192169A successfully refreshed from Google Patents.
US3192169A
Expired / Lapsed
US
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Method of making expandable polymeric styrene particles
Assignee: Atlantic Richfield Co
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Filing: 1965-01-07
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Granted: 1965-06-29
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Expires: 1985-01-07
Abstract
No abstract record available.
Inventors
- 👤 Kenneth W Doak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:37
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
118 words
A METHOD OF MAKING EXPANDABLE POLYMERIC STYRENE PARTICLES COMPRISING POLMERIZING A STYRENE MONOMER IN AQUEOUS SUSPENSION BY HEATING SAID MONOMER IN THE PRESENCE OF A CATALYST, CONSISTING ESSENTIALLY OF AT LEAST ONE LOW TEMPERATURE PEROXIDIC INITIATOR AND AT LEAST ONE HIGH TEMPERATURE PEROXIDIC INITIATOR, TO A TEMPERATURE AT WHICH SAID LOW TEMPERATURE INITIATOR SERVES AS THE PRINCIPAL INITIATOR, CONTINUING POLYMERIZATION AT LEAST UNTIL THE PARTICLE IDENTIY POINT IS REACHED, THEREAFTER ADDING A NORMALLY LIQUID HYDROCARBON BLOWING AGENT, RAISING THE TEMPERATURE TO THAT AT WHICH SAID HIGH TEMPERATURE INITIATOR SERVES AS THE PRINCIPAL INITIATOR, AND CONTINUING HEATING UNTIL POLYMERIZATION IS SUBSTANTIALLY COMPLETE AS EVIDENCED BY THE PRESENCE OF LESS THAN 0.5% BY WEIGHT RESIDUAL MONOMER IN THE POLYMER PARTICLES.
Claim 2
Independent Claim
118 words
A METHOD OF MAKING EXPANDABLE POLYMERIC STYRENE PARTICLES COMPRISING POLMERIZING A STYRENE MONOMER IN AQUEOUS SUSPENSION BY HEATING SAID MONOMER IN THE PRESENCE OF A CATALYST, CONSISTING ESSENTIALLY OF AT LEAST ONE LOW TEMPERATURE PEROXIDIC INITIATOR AND AT LEAST ONE HIGH TEMPERATURE PEROXIDIC INITIATOR, TO A TEMPERATURE AT WHICH SAID LOW TEMPERATURE INITIATOR SERVES AS THE PRINCIPAL INITIATOR, CONTINUING POLYMERIZATION AT LEAST UNTIL THE PARTICLE IDENTIY POINT IS REACHED, THEREAFTER ADDING A NORMALLY LIQUID HYDROCARBON BLOWING AGENT, RAISING THE TEMPERATURE TO THAT AT WHICH SAID HIGH TEMPERATURE INITIATOR SERVES AS THE PRINCIPAL INITIATOR, AND CONTINUING HEATING UNTIL POLYMERIZATION IS SUBSTANTIALLY COMPLETE AS EVIDENCED BY THE PRESENCE OF LESS THAN 0.5% BY WEIGHT RESIDUAL MONOMER IN THE POLYMER PARTICLES.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-06-28 | 1968-12-28 | 1969-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-06-28 | 1972-12-28 | 1973-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-06-28 | 1976-12-28 | 1977-06-29 | $7700.00 | Window Closed / Lapsed |