Patent US2857369A successfully refreshed from Google Patents.
US2857369A
Expired / Lapsed
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Separation of linear polyethylene
Assignee: EIDP Inc
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Filing: 1957-03-01
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Granted: 1958-10-21
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Expires: 1977-03-01
Abstract
No abstract record available.
Inventors
- 👤 Johnson Edwin David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:59
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
IN A PROCESS OF SEPARATING HIGH MOLECULAR WEIGHT LINEAR POLYETHYLENE FROM LOW MOLECULAR WEIGHT POLYMER FRACTIONS WHICH COMPRISES FORMING A SOLUTION OF A MIXTURE THEREOF IN A HYDROCARBON SOLVENT, HEATING THE RESULTING SOLUTION TO A TEMPERATURE ABOVE THE CRITICAL TEMEPRATURE OF SAID SOLVENT UNDER A SUFFICIENT PRESURE TO MAINTAIN THE DENSITY OF THE SOLVENT IN THE POLYMER-SOLVENT PHASE ABOVE THE PRECIPITATION DENSITY AND THEN LOWERING THE PRESSURE TO CUSE THE DENSITY OF THE SOLVENT IN THE POLYMER-SOLVENT PHASE TO DROP BELOW THE PRECIPITATRION DENSITY WHILE MAINTAINING THE TEMPERATURE ABOVE THE CRITICAL TEMPERATURE OF THE SOLVENT AND RECOVERING AS SEPARATE PHASES THE HIGH MOLECULAR WEIGHT POLYMER AND SOLVENT-LOW MOLECULAR WEIGPOLYMER MIXTURE.
Claim 2
Dependent Claim
110 words
IN A PROCESS OF SEPARATING HIGH MOLECULAR WEIGHT LINEAR POLYETHYLENE FROM LOW MOLECULAR WEIGHT POLYMER FRACTIONS WHICH COMPRISES FORMING A SOLUTION OF A MIXTURE THEREOF IN A HYDROCARBON SOLVENT, HEATING THE RESULTING SOLUTION TO A TEMPERATURE ABOVE THE CRITICAL TEMEPRATURE OF SAID SOLVENT UNDER A SUFFICIENT PRESURE TO MAINTAIN THE DENSITY OF THE SOLVENT IN THE POLYMER-SOLVENT PHASE ABOVE THE PRECIPITATION DENSITY AND THEN LOWERING THE PRESSURE TO CUSE THE DENSITY OF THE SOLVENT IN THE POLYMER-SOLVENT PHASE TO DROP BELOW THE PRECIPITATRION DENSITY WHILE MAINTAINING THE TEMPERATURE ABOVE THE CRITICAL TEMPERATURE OF THE SOLVENT AND RECOVERING AS SEPARATE PHASES THE HIGH MOLECULAR WEIGHT POLYMER AND SOLVENT-LOW MOLECULAR WEIGPOLYMER MIXTURE.
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) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |