Patent US3445561A successfully refreshed from Google Patents.
US3445561A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polycarbonate films and product thereof
Assignee: Bayer AG
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Filing: 1963-06-21
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Granted: 1969-05-20
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Expires: 1983-06-21
Abstract
No abstract record available.
Inventors
- 👤 Karl Huff
- 👤 Hermann Hofmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:32
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/02; B; B29; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; B29C59/00; C08J2369/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
A PROCESS FOR THE PRODUCTION OF POLYCARBONATE FILMS HAVING IMPROVED PHYSICAL PROPERTIES WHICH COMPRISES FORMING A POLYCARBONATE FILM HAVING A CRYSTALLINITY OF AT LEAST ABOUT 10%, LONGITUDINALLY STRETCHING SAID FILM TO FROM ABOUT 2 TO ABOUT 8 TIMES ITS ORGININAL LENGTH AND SUBSEQUENTLY SHRINKING SAID FILM WHILE SUBSTANTIALLY FREE OF TENSION IN ITS LONGITUDINAL DIRECTION IN AN AMOUNT AT LEAST ABOUT 3% OF ITS STRETCHED LENGTH.
Claim 2
Dependent Claim
66 words
A PROCESS FOR THE PRODUCTION OF POLYCARBONATE FILMS HAVING IMPROVED PHYSICAL PROPERTIES WHICH COMPRISES FORMING A POLYCARBONATE FILM HAVING A CRYSTALLINITY OF AT LEAST ABOUT 10%, LONGITUDINALLY STRETCHING SAID FILM TO FROM ABOUT 2 TO ABOUT 8 TIMES ITS ORGININAL LENGTH AND SUBSEQUENTLY SHRINKING SAID FILM WHILE SUBSTANTIALLY FREE OF TENSION IN ITS LONGITUDINAL DIRECTION IN AN AMOUNT AT LEAST ABOUT 3% OF ITS STRETCHED LENGTH.
References Cited (Backward Citations)
CA622443A
Cited
US2979774A
Cited
US2974370A
Cited
US3083071A
Cited
US3073002A
Cited
US3214500A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-19 | 1972-11-18 | 1973-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-19 | 1976-11-18 | 1977-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-19 | 1980-11-18 | 1981-05-20 | $7700.00 | Window Closed / Lapsed |