Patent US3245973A successfully refreshed from Google Patents.
US3245973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for polymerizing unsaturated hydrocarbons to crystalline polymers of regulated molecular weight
Assignee: Montedison SpA
•
Filing: 1958-11-03
•
Granted: 1966-04-12
•
Expires: 1978-11-03
Abstract
No abstract record available.
Inventors
- 👤 Natta Giulio
- 👤 Pasquon Italo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:53
CPC Classifications
C; C08; C08F; C08F10/00; C08F110/00; C08F110/04; C08F110/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
77 words
IN A PROCESS FOR POLYMERIZING PROPYLENE TO A POLYMERIZATE CONSISTING PREVAILING OF ISOTACTIC MACROMOLECULES IN AN INERT LIQUID DILUENT AN IN CONTACT WITH A SOLID, SUBSTANTIALLY CRYSTALLINE CATALYST PREPARED BY MIXING SOLID, CRYSTALLINE TITANIUM TRICHLORIDE WITH TRIETHYL ALUMNUM, THE IMPROVEMENT WHICH COMPRISES REGULATING THE MOLECULAR WEIGHT OF THE POLYMERIZATE PRODUCED BY POLYMERIZING THE PROPYLENE WITH SAID CATALYST IN THE PRESENCE OF ZINC DIETHYL, THE MOLAR RATIO OF ZINC DIETHYL TO TRIETHYL ALUMINUM BEING FROM 0.1:1 TO 20:1.
Claim 2
Dependent Claim
77 words
IN A PROCESS FOR POLYMERIZING PROPYLENE TO A POLYMERIZATE CONSISTING PREVAILING OF ISOTACTIC MACROMOLECULES IN AN INERT LIQUID DILUENT AN IN CONTACT WITH A SOLID, SUBSTANTIALLY CRYSTALLINE CATALYST PREPARED BY MIXING SOLID, CRYSTALLINE TITANIUM TRICHLORIDE WITH TRIETHYL ALUMNUM, THE IMPROVEMENT WHICH COMPRISES REGULATING THE MOLECULAR WEIGHT OF THE POLYMERIZATE PRODUCED BY POLYMERIZING THE PROPYLENE WITH SAID CATALYST IN THE PRESENCE OF ZINC DIETHYL, THE MOLAR RATIO OF ZINC DIETHYL TO TRIETHYL ALUMINUM BEING FROM 0.1:1 TO 20:1.
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) | 1969-04-11 | 1969-10-11 | 1970-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-11 | 1973-10-11 | 1974-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-11 | 1977-10-11 | 1978-04-12 | $7700.00 | Window Closed / Lapsed |