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US4110395A
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Process for producing polymeric films from crystallizable polyesters
Assignee: Individual
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Filing: 1976-10-19
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Granted: 1978-08-29
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Expires: 1996-10-19
Abstract
Abstract A process for producing polymeric films from crystallizable polyesters, such as polyethylene terephthalate, comprising extruding a molten polymer onto a receiving surface with subsequent cooling of the polymer on said surface at 20°-80° C. to obtain an amorphous polymeric film. This film is heat-treated at 130°-190° C. to obtain a crystallinity of the film of 5-50%. Then the film is oriented at 130°-250° C., thermally fixed at 170°-250° C. and cooled at 20°-30° C. Polymeric films produced by the above-described method have a high structural homogeneity and elevated physical and mechanical characteristics (ultimate tensile strength up to 4000 kg/cm 2 , yield point up to 3500 kg/cm 2 ).
Inventors
- 👤 Modest S. Akutin
- 👤 Tamara G. Levina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:59
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/005; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/001; B29C48/0018; B29K; B29K2067/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
76 words
A process for producing polymeric polyethyleneterephthalate films, comprising the extrusion of molten polyethyleneterephthalate polymer onto a receiving surface; cooling said polymer on said receiving surface to a temperature of 20°-80° C. to obtain an amorphous polymeric film; heat treating said film at 130°-190° C. to obtain a degree of crystallinity of the film of from 5 to 50%; biaxially orienting said film at 130°-250° C.; thermal fixation thereof at 170°-250° C. and cooling to 20°-30° C.
Claim 2
Dependent Claim
76 words
A process for producing polymeric polyethyleneterephthalate films, comprising the extrusion of molten polyethyleneterephthalate polymer onto a receiving surface; cooling said polymer on said receiving surface to a temperature of 20°-80° C. to obtain an amorphous polymeric film; heat treating said film at 130°-190° C. to obtain a degree of crystallinity of the film of from 5 to 50%; biaxially orienting said film at 130°-250° C.; thermal fixation thereof at 170°-250° C. and cooling to 20°-30° C.
Claim 3
Dependent Claim
31 words
The process of claim 1, wherein the biaxial orientation of said film is simultaneously conducted in both directions until an ultimate strength of the film of 3600 kg/cm 2 is reached.
Claim 4
Dependent Claim
38 words
The process of claim 1, wherein the biaxial orientation of said film is conducted consecutively: first in a longitudinal, and then in a lateral direction until an ultimate strength of the film of 3600 kg/cm 2 is reached.
Claim 5
Dependent Claim
22 words
The process of claim 1, wherein the polymer film is cooled to 20°-80° C. after heat treatment and prior to the orientation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |