US5292471A
Expired / Lapsed
US
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Process for forming a polyester film
Assignee: Toray Industries Inc
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Filing: 1993-06-09
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Granted: 1994-03-08
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Expires: 2013-06-09
Abstract
Abstract A polyester film, which is substantially non-oriented and whose main component is polyethylene terephthalate, is formed into a shape for example, a package, at a condition causing no yield point. The formation ability of the polyester film for forming is improved, and a formed body having a good uniformity in thickness can be obtained. Further, the range of the temperature condition causing no yield point can be enlarged by laminating a PET-system polyester, which originally tends to cause a yield point by itself, onto a polyester having no yield point. In such a laminated polyester film, the slipping property and releasing property from a mold of the film can be improved by specifying the ranges of the degree of crystallinity of each layer, the adhesive force at a high temperature of the film and the surface roughness of the film, and the shape of a formed body can be improved.
Inventors
- 👤 Tatsuya Ito
- 👤 Kenji Tsunashima
- 👤 Hideyuki Yamauchi
- 👤 Seizo Aoki
- 👤 Hirokazu Kurome
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:43
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B32; B32B; B32B27/00; B32B27/36; C08J2367/00; C08J2367/02; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
76 words
A process for forming a polyester film comprising the step of forming a laminated film, which is made by laminating a polyester A-layer having no yield point in a temperature range of a glass transition temperature thereof to 140° C. onto a substantially non-oriented polyester B-layer whose main component is polyethylene terephthalate, at a condition causing said laminated film to have no yield point at a temperature in the range of 80° C. to 140° C.
Claim 2
Dependent Claim
76 words
A process for forming a polyester film comprising the step of forming a laminated film, which is made by laminating a polyester A-layer having no yield point in a temperature range of a glass transition temperature thereof to 140° C. onto a substantially non-oriented polyester B-layer whose main component is polyethylene terephthalate, at a condition causing said laminated film to have no yield point at a temperature in the range of 80° C. to 140° C.
Claim 3
Dependent Claim
44 words
The process according to claim 1, wherein said polyester film is capable of possessing no yield point throughout a temperature range not less than a range of 35° C. within the range of a temperature of 80° C. to a temperature of 140° C.
Claim 4
Dependent Claim
31 words
The process according to claim 1, wherein the stretching tension of said A-layer is in the range of from 5 times to 100 times of the stretching tension of said B-layer.
Claim 5
Dependent Claim
32 words
The process according to claim 1, wherein the degree of crystallinity of said A-layer is in the range of 5-20%, and the degree of crystallinity of said B-layer is less than 5%.
Claim 6
Dependent Claim
31 words
The process according to claim 1, wherein the adhesive force between the surface of said A-layer and a metal at a temperature of 100° C. is not greater than 20 g.
Claim 7
Dependent Claim
22 words
The process according to claim 1, wherein the mean surface roughness (Ra) of said A-layer is in the range of 0.005-0.1 μm.
Claim 8
Dependent Claim
23 words
The process according to claim 1, wherein the thickness of said A-layer is not less than 1 μm and less than 50 μm.
Claim 9
Dependent Claim
23 words
The process according to claim 1, wherein the thickness of said A-layer is not less than 3 μm and less than 10 μm.
Claim 10
Dependent Claim
27 words
The process according to claim 1, wherein the thickness of said A-layer is less than 15% of the total thickness of said polyester film to be formed.
Claim 11
Dependent Claim
12 words
The process according to claim 1, wherein said A-layer contains inert particles.
Claim 12
Dependent Claim
22 words
The process according to claim 10, wherein the mean particle diameter of said inert particles is in the range of 0.01-10 μm.
Claim 13
Dependent Claim
32 words
The process according to claim 10, wherein said inert particles are inorganic particles selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, calcium carbonate, magnesium carbonate and talc particles.
Claim 14
Dependent Claim
27 words
The process according to claim 10, wherein said inert particles are organic particles selected from the group consisting of cross-linked polystyrene, cross-linked divinylbenzene, benzoguanamine or silicone particles.
Claim 15
Dependent Claim
23 words
The process according to claim 1, wherein the ratio in thickness between said A-layer and said B-layer is in the range of 1:200-1:4.
References Cited (Backward Citations)
US3197538A
Cited
US3577510A
Cited
US3547891A
Cited
US3871947A
Cited
US3975485A
Cited
US4020126A
Cited
JPS5138335A
Cited
US4606976A
Cited
JPS6219090A
Cited
US4765999A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
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