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US3361728A
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Films of improved characteristics from alpha-olefin polymers and process for preparing them
Assignee: Montedison SpA
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Filing: 1963-05-27
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Granted: 1968-01-02
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Expires: 1983-05-27
Abstract
No abstract record available.
Inventors
- 👤 Coen Alberto
- 👤 Sebastiano Francesco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:35
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/02; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29D; B29D7/00; B29D7/01
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
105 words
A PROCESS FOR PREPARING A FILM FROM POLYPROPYLENE CONSISTING ESSENTIALLY OF ISOTACTIC MACROMOLECULES, SAID FILM HAVING A MAXIMUM HAZE OF ABOUT 6% AND A CRYSTALLINITY OF ABOUT 50 TO 60% AND BEING COMPRISED OF SMALL CRYSTALS, WHICH PROCESS COMPRISES HEATING A PREFORMED, TRANSPARENT POLYPROPYLENE FILM, NON-STRETCHED SUBSEQUENT TO ITS FORMATION, HAVING A CRYSTALLINITY OF ABOUT 30% AND A GOOD GLOSS, AT A TEMPERATURE BETWEEN 60* AND 150*C. FOR A TIME BETWEEN 1 SECOND AND 60 MINUTES, WITHOUT SUBJECTING THE FILM TO STRETCHING DURING THIS HEAT TREATMENT, WHEREBY THE SLIP OF THE FILM IS INCREASED MARKEDLY WITHOUT SUBSTANTIALLY DECREASING THE GLOSS OR TRANSPARENCY OF THE FILM.
Claim 2
Dependent Claim
105 words
A PROCESS FOR PREPARING A FILM FROM POLYPROPYLENE CONSISTING ESSENTIALLY OF ISOTACTIC MACROMOLECULES, SAID FILM HAVING A MAXIMUM HAZE OF ABOUT 6% AND A CRYSTALLINITY OF ABOUT 50 TO 60% AND BEING COMPRISED OF SMALL CRYSTALS, WHICH PROCESS COMPRISES HEATING A PREFORMED, TRANSPARENT POLYPROPYLENE FILM, NON-STRETCHED SUBSEQUENT TO ITS FORMATION, HAVING A CRYSTALLINITY OF ABOUT 30% AND A GOOD GLOSS, AT A TEMPERATURE BETWEEN 60* AND 150*C. FOR A TIME BETWEEN 1 SECOND AND 60 MINUTES, WITHOUT SUBJECTING THE FILM TO STRETCHING DURING THIS HEAT TREATMENT, WHEREBY THE SLIP OF THE FILM IS INCREASED MARKEDLY WITHOUT SUBSTANTIALLY DECREASING THE GLOSS OR TRANSPARENCY OF THE FILM.
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) | 1971-01-01 | 1971-07-03 | 1972-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-01-01 | 1975-07-03 | 1976-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-01-01 | 1979-07-03 | 1980-01-02 | $7700.00 | Window Closed / Lapsed |