US3619461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stretching process for polyimide film
Assignee: EIDP Inc
•
Filing: 1969-03-25
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Granted: 1971-11-09
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Expires: 1989-03-25
Abstract
Abstract A process of immersing in a volatile liquid a polyimide film of low volatile content, and heating and stretching or restraining the treated film to increase the orientation in at least one direction.
Inventors
- 👤 Frank P Gay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:49
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/005
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
44 words
A process of claim 1 further comprising contacting the film with a second liquid selected from acetone and methylene chloride before stretching the film and after contacting the film with the liquid, whereby the liquid is at least partly replaced by the second liquid.
References Cited (Backward Citations)
CA591604A
Cited
US2547763A
Cited
US2896262A
Cited
US3179614A
Cited
US3179632A
Cited
US3179630A
Cited
US3413267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |