Patent US3374213A successfully refreshed from Google Patents.
US3374213A
Expired / Lapsed
US
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Polypropylene polymerization process
Assignee: Dart Industries Inc
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Filing: 1962-11-02
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Granted: 1968-03-19
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Expires: 1982-11-02
Abstract
No abstract record available.
Inventors
- 👤 Donald F Hoeg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:46
CPC Classifications
C; C08; C08F; C08F210/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
60 words
THE PROCESS FOR POLYMERIZING PROPYLENE SO AS TO OBTAIN A SOLID POLYMER PRODUCT HAVING DECREASED LOW TEMPERATURE BRITTLENESS WHICH COMPRISES POLYMERIZING THE PROPYLENE FEED WITH A STEREO-SPECIFIC CATALYST SYSTEM OF TITANIUM TRICHLORIDE/TRIETHYL ALUMINUM, THE TITANIUM TRICHLORIDE HAVING THE FORMULA 3TICL3 ALCL3 IN THE PREENCE OF FROM 5 TO 15 VOLUME PERCENT OFETHYLENE BASED ON PROPYLENE AT A TEMPERATURE ABOVE 100*C.
Claim 2
Dependent Claim
60 words
THE PROCESS FOR POLYMERIZING PROPYLENE SO AS TO OBTAIN A SOLID POLYMER PRODUCT HAVING DECREASED LOW TEMPERATURE BRITTLENESS WHICH COMPRISES POLYMERIZING THE PROPYLENE FEED WITH A STEREO-SPECIFIC CATALYST SYSTEM OF TITANIUM TRICHLORIDE/TRIETHYL ALUMINUM, THE TITANIUM TRICHLORIDE HAVING THE FORMULA 3TICL3 ALCL3 IN THE PREENCE OF FROM 5 TO 15 VOLUME PERCENT OFETHYLENE BASED ON PROPYLENE AT A TEMPERATURE ABOVE 100*C.
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) | 1971-03-19 | 1971-09-18 | 1972-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-03-19 | 1975-09-18 | 1976-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-03-19 | 1979-09-18 | 1980-03-19 | $7700.00 | Window Closed / Lapsed |