Patent US4234532A successfully refreshed from Google Patents.
US4234532A
Expired / Lapsed
US
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Method of manufacturing polyester films
Assignee: Toray Industries Inc
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Filing: 1979-08-14
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Granted: 1980-11-18
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Expires: 1999-08-14
Abstract
Abstract The present invention relates to a process for preparing a highly tensilized polyester film that has enhanced mechanical properties in both longitudinal and transverse directions. The process involves the simultaneous machine and transverse direction stretching and subsequent heat setting of a film that has already been highly stretched in the machine and transverse directions individually. During the simultaneous stretching process both the temperature and rate of linear movement of the film are controlled.
Inventors
- 👤 Masahiko Motegi
- 👤 Ikukazu Kimata
- 👤 Saburo Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:36
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/10; B29C55/12
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
112 words
In a process for preparing highly tensilized polyester film having F-5 values over 14 kg/mm 2 in both MD and TD, the steps which comprises stretching a polyester film to an extent of at least 2.6 times its dimensions in MD and TD, simultaneously stretching the resulting film in the range of 1.05 to 1.9 times its dimensions in MD and 1.0 to 1.9 times its dimensions in TD at a linear rate of stretch speed under 8,000 percent per minute at a temperature between T g +10° C. and T m -40° C., and heat setting said film at a temperature between T g +50° C. and T m -10° C.
Claim 2
Dependent Claim
112 words
In a process for preparing highly tensilized polyester film having F-5 values over 14 kg/mm 2 in both MD and TD, the steps which comprises stretching a polyester film to an extent of at least 2.6 times its dimensions in MD and TD, simultaneously stretching the resulting film in the range of 1.05 to 1.9 times its dimensions in MD and 1.0 to 1.9 times its dimensions in TD at a linear rate of stretch speed under 8,000 percent per minute at a temperature between T g +10° C. and T m -40° C., and heat setting said film at a temperature between T g +50° C. and T m -10° C.
Claim 3
Dependent Claim
25 words
A process as defined in claim 1, wherein said linear rate of stretch speed in said simultaneous stretching step is under 5,000 percent per minute.
Claim 4
Dependent Claim
26 words
A process as defined in claim 1, wherein the stretch ratio and the linear rate of stretch speed in MD and TD are substantially the same.
Claim 5
Dependent Claim
25 words
A process as defined in claim 1, wherein the stretch ratio and the linear rate of stretch speed in MD and TD are substantially different.
Claim 6
Dependent Claim
68 words
A process as defined in claim 1, wherein said polyester film is selected from the group consisting of a polyethylene terephthalate copolyester consisting of at least 70 wt. % of polyethylene terephthalate and up to 15 wt. % of another ester forming monomer, and blends consisting of at least 70 wt. % of polyethylene terephthalate and up to 15 wt. % of other polymers and/or additives, or polyethylene-2,6-naphathalate.
Claim 7
Dependent Claim
22 words
A process as defined in claim 1, wherein said polyester film has an intrinsic viscosity in the range of 0.5 to 1.0.
Claim 8
Dependent Claim
22 words
A process as defined in claim 1, wherein said polyester film has an intrinsic viscosity in the range of 0.55 to 0.9.
Claim 9
Dependent Claim
55 words
A process as defined in claim 1, wherein the simultaneous stretching is performed by pulling the film in the machine direction and by simultaneously grasping the edges of said film at a multiplicity of spaced-apart locations arranged along opposite edges of said film and pulling said film in the transverse direction at said grasping locations.
Claim 10
Dependent Claim
16 words
A process as defined in claim 8, wherein said simultaneous stretching comprises a tentor stretching step.
Claim 11
Dependent Claim
48 words
A process as defined in claim 1, wherein the MD stretch ratio of said film prior to simultaneous post-stretching, multiplied by the post-stretch ratio in MD is substantially equal to the TD stretch ratio of said film prior to simultaneous post-stretching multiplied by the post-stretch ratio in TD.
Claim 12
Dependent Claim
19 words
A process as defined in claim 8, wherein the product of such ratio multiplication is greater than about 4.0.
Claim 13
Dependent Claim
19 words
A process as defined in claim 8, wherein the product of such ratio multiplication is greater than about 4.5.
Claim 14
Dependent Claim
19 words
A process as defined in claim 8, wherein the product of such ratio multiplication is greater than about 5.0.
Claim 15
Dependent Claim
19 words
A process as defined in claim 8, wherein the product of such ratio multiplication is greater than about 5.5.
Claim 16
Dependent Claim
41 words
A process as defined in claim 1, wherein said stretching of at least 2.6 times of a biaxially high oriented film used for simultaneous stretching was conducted at a temperature in the range of T g to T g +60° C.
Claim 17
Dependent Claim
43 words
A process as defined in claim 1, wherein said stretching of at least 2.6 times of a biaxially high oriented film used for simultaneous stretching was conducted at a temperature in the range of T g +10° C. to T g +40° C.
Claim 18
Dependent Claim
34 words
A process as defined in claim 13, wherein said stretching of a biaxially high oriented film used for simultaneous stretching is conducted within the range of 2.6 to 6.0 times the film's original dimensions.
Claim 19
Dependent Claim
34 words
A process as defined in claim 13, wherein said stretching of a biaxially high oriented film used for simultaneous stretching is conducted within the range of 2.8 to 5.0 times the film's original dimensions.
Claim 20
Dependent Claim
31 words
A process as defined in claim 13, wherein the film is subsequently stretched in a different direction at a temperature in the range of T g to T g +80° C.
Claim 21
Dependent Claim
31 words
A process as defined in claim 13, wherein the film is subsequently stretched in a different direction at a temperature in the range of T g to T g +60° C.
Claim 22
Dependent Claim
33 words
A process as defined in claim 1 wherein the biaxially oriented film is pre-heat set at a temperature between the temperature of the simultaneous post-stretch (T s ) and T m -10° C.
Claim 23
Dependent Claim
28 words
A process as defined in claim 1 wherein the biaxially oriented film is pre-heat set at a temperature between T s +5° C. and T s +30° C.
Claim 24
Dependent Claim
23 words
A process as defined in claim 1 wherein the temperature for simultaneous post-stretching is 10° C. above the temperature used for biaxially stretching.
Claim 25
Dependent Claim
27 words
A process as defined in claim 1 wherein the temperature for simultaneous post-stretching is within the range of T g +40° C. to T m -60° C.
Claim 26
Dependent Claim
31 words
A process as defined in claim 1 wherein the simultaneously post-stretched film is heat set in the temperature range of T g +80° C. and T m -20° C., under tension.
Claim 27
Dependent Claim
17 words
A process as defined in claim 25, wherein the film is subjected to relaxation while heat setting.
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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |