Patent US3720732A successfully refreshed from Google Patents.
US3720732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biaxially oriented polycarbonate modified polyester film
Assignee: 3M Co
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Filing: 1970-09-18
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Granted: 1973-03-13
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Expires: 1990-09-18
Abstract
Abstract PHYSICALLY BLENDING SMALL AMOUNTS OF POLYCARBONATE RESIN INTO POLYETHYLENE TEREPHTHALATE RESIN WHICH IS TO BE EXTRUDED INTO A FILM AND THEREAFTER ORIENTED, IMPARTS UNEXPECTEDLY SUPERIOR HEAT STABILITY TO THE ULTIMATE FILM, THIS FILM ALSO DISPLAYS IMPROVED "SLIP" PROPERTIES, NO ONLY PERMITTING THE OMISSION OF CONVENTIONAL HARD INORGENIC SLIP AGENTS BUT ALSO ATTAINING A MORE UNIFORM SURFACE. ELECTRICAL PROPERTIES ARE ALSO IMPROVED.
Inventors
- 👤 R Sevenich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:56
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02; C08J; C08J5/00; C08J5/18; C08J2367/00; C08J2367/02; C08J2469/00
Claims Analysis
Total Claims: 0
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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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |