Patent US2958686A successfully refreshed from Google Patents.
US2958686A
Expired / Lapsed
US
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Purifying organometal-catalyzed isotactic polystyrene by chlorination
Assignee: Eastman Kodak Co
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Filing: 1959-06-23
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Granted: 1960-11-01
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Expires: 1979-06-23
Abstract
No abstract record available.
Inventors
- 👤 Kenneth R Dunbam
- 👤 Berghe John Van Den
- 👤 William J Dulmage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:01
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/18; C08F8/20; C08F10/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PROCESS FRO PURIFYING AN ISOTACTIC POLYSTYRENE CONTAINING CATALYST RESIDUES DERIVED FROM A CATALYST COMPRISING AN ORGANO-ALUMINUM COMPOUND HAVING ALUMINUM TO CARBON BONDS AND A HALIDE OF A TRANSITION METAL OF GROUPS IV TO VI OF MENDELEEF''S PERIODIC ARRANGEMENT OF THE ELEMENTS, SAID MIXED CATALYST HAVING BEEN USED IN THE PREPARATION OF THE SAID POLYSTYRENE, WHICH COMPRISES THE STEPS (1) HEATING THE SAID POLYSTYRENE, IN AN AROMATIC HYDROCARBON SOLVENT HAVING A BOILING POINT ABOUT FROM 110*-215* C, UNTIL A HOMOGENEOUS SOLUTION IS OBTAINED (2) PASSING CHLORINE AND NITROGEN GASES SIMULTANEOUSLY INTO SAID SOLUTION MAINTAINED AT A TEMPERATURE OF FROM 130*-215*C. AND (3) FILTERING THE SAID SOLUTION IN A HEATED CONDITION.
Claim 2
Dependent Claim
110 words
A PROCESS FRO PURIFYING AN ISOTACTIC POLYSTYRENE CONTAINING CATALYST RESIDUES DERIVED FROM A CATALYST COMPRISING AN ORGANO-ALUMINUM COMPOUND HAVING ALUMINUM TO CARBON BONDS AND A HALIDE OF A TRANSITION METAL OF GROUPS IV TO VI OF MENDELEEF''S PERIODIC ARRANGEMENT OF THE ELEMENTS, SAID MIXED CATALYST HAVING BEEN USED IN THE PREPARATION OF THE SAID POLYSTYRENE, WHICH COMPRISES THE STEPS (1) HEATING THE SAID POLYSTYRENE, IN AN AROMATIC HYDROCARBON SOLVENT HAVING A BOILING POINT ABOUT FROM 110*-215* C, UNTIL A HOMOGENEOUS SOLUTION IS OBTAINED (2) PASSING CHLORINE AND NITROGEN GASES SIMULTANEOUSLY INTO SAID SOLUTION MAINTAINED AT A TEMPERATURE OF FROM 130*-215*C. AND (3) FILTERING THE SAID SOLUTION IN A HEATED CONDITION.
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) | 1963-11-01 | 1964-05-02 | 1964-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-01 | 1968-05-02 | 1968-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-01 | 1972-05-02 | 1972-11-01 | $7700.00 | Window Closed / Lapsed |