US4478772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing cast film of thermoplastic resin
Assignee: Teijin Ltd
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Filing: 1983-04-21
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Granted: 1984-10-23
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Expires: 2003-04-21
Abstract
Abstract A process for preparing a thermoplastic resin film by extruding a molten thermoplastic film-forming resin in the form of a continuous molten film onto an electrically grounded moving quenching surface, passing the molten film in proximity to but out of contact with at least one electrode which imparts an electrostatic charge to the film across its full width and withdrawing a solidified film thus formed from said quenching surface; which process comprises extruding the molten film onto a quenching surface characterized by having a channel-like microcracked structure.
Inventors
- 👤 Norio Takagi
- 👤 Hiroshi Aoyagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:41
CPC Classifications
B; B29; B29C; B29C41/00; B29C41/24; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29C48/915; B29C48/9165
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
85 words
A process for preparing a thermoplastic resin film by extruding a molten thermoplastic film-forming resin in the form of a continuous molten film onto an electrically grounded moving quenching surface, passing the molten film in proximity to but out of contact with at least one electrode which imparts an electrostatic charge to the film across its full width, and withdrawing a solidified film thus formed from said quenching surface; which process comprises extruding the molten film onto a quenching surface having a channel-like microcracked structure.
Claim 2
Dependent Claim
85 words
A process for preparing a thermoplastic resin film by extruding a molten thermoplastic film-forming resin in the form of a continuous molten film onto an electrically grounded moving quenching surface, passing the molten film in proximity to but out of contact with at least one electrode which imparts an electrostatic charge to the film across its full width, and withdrawing a solidified film thus formed from said quenching surface; which process comprises extruding the molten film onto a quenching surface having a channel-like microcracked structure.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the quenching surface has a profile-bearing rate of at least about 30%.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein the quenching surface has a profile-bearing rate of about 40% to about 99%.
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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |