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US5703202A
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Process for treating liquid crystal polymer film
Assignee: Kuraray Co Ltd
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Filing: 1996-04-02
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Granted: 1997-12-30
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Expires: 2016-04-02
Abstract
Abstract A process for treating a liquid crystal polymer film which includes the steps of: heating a film obtained by extrusion molding of a liquid crystal polymer, while contacting at least one surface of the film with a supporting body, to melt the polymer; cooling the melted polymer to form a solidified polymer layer; and separating the solidified polymer layer from the supporting body. The process readily provides liquid crystal polymer films having excellent resistance to intra-layer delamination and high tensile strength and elongation, as well as excellent resistance to abrasion, dimensional stability when heated, and resistance to folding.
Inventors
- 👤 Randy Douglas Jester
- 👤 John Arthur Penoyer
- 👤 Douglas Duane Roth
- 👤 Detlef Frank
- 👤 Minoru Onodera
- 👤 Takeichi Tsudaka
- 👤 Toshiaki Sato
- 👤 Tohei Moritani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:23
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/02; B29C48/00; B29C48/001; B29C48/0018; B29C48/03; B29C48/07; B29C48/08; B29C48/16; B29C48/18; B29C48/21; B29K; B29K2105/00; B29K2105/0079; B29L; B29L2007/00; B29L2007/008
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
283 words
A heat-treated polymer film made by the process comprising the steps of: (a) heating a film made by the extrusion molding of a polymer capable of forming an optically anisotropic melt phase while contacting at least one surface of said film with a supporting body, to a temperature sufficient to melt said polymer; (b) cooling the melted polymer to form a solidified polymer layer; and (c) separating said solidified polymer layer from said supporting body; said heat-treated polymer film having an intra-layer peeling strength measured by conducting a 90° peeling test in accordance with JIS C6471 of at least 2 kg/cm; a tensile strength measured in accordance with JIS C2318 of at least 5 kg/mm 2 ; a thermal expansion coefficient that is positive when measured along four different lines in the film plane, wherein each of said four lines passes through a common point on the film plane, with the second line being at an angle of 45° with respect to the first line, with the third line being at an angle of 45° with respect to the second line, and with the fourth line being at an angle of 45° with respect to the third line; and a dimensional change ratio when heated of not more than 0.1% in its absolute value, wherein said ratio is (L 1 -L 0 )/L 0 !×100%, where L 0 is the length of a film sample measured at 25° C. and L 1 is the length of the same film sample measured at 25° C. after being heated in air at 190° C. for 30 minutes under no tension; and a degree of planar orientation of 50 to 70% as measured by x-ray diffractometry.
Claim 2
Dependent Claim
283 words
A heat-treated polymer film made by the process comprising the steps of: (a) heating a film made by the extrusion molding of a polymer capable of forming an optically anisotropic melt phase while contacting at least one surface of said film with a supporting body, to a temperature sufficient to melt said polymer; (b) cooling the melted polymer to form a solidified polymer layer; and (c) separating said solidified polymer layer from said supporting body; said heat-treated polymer film having an intra-layer peeling strength measured by conducting a 90° peeling test in accordance with JIS C6471 of at least 2 kg/cm; a tensile strength measured in accordance with JIS C2318 of at least 5 kg/mm 2 ; a thermal expansion coefficient that is positive when measured along four different lines in the film plane, wherein each of said four lines passes through a common point on the film plane, with the second line being at an angle of 45° with respect to the first line, with the third line being at an angle of 45° with respect to the second line, and with the fourth line being at an angle of 45° with respect to the third line; and a dimensional change ratio when heated of not more than 0.1% in its absolute value, wherein said ratio is (L 1 -L 0 )/L 0 !×100%, where L 0 is the length of a film sample measured at 25° C. and L 1 is the length of the same film sample measured at 25° C. after being heated in air at 190° C. for 30 minutes under no tension; and a degree of planar orientation of 50 to 70% as measured by x-ray diffractometry.
Claim 3
Dependent Claim
35 words
The heat-treated polymer film as recited in claim 1, wherein said supporting body comprises a metal foil, and wherein said separating step (c) is accomplished by dissolving said metal foil off of said polymer layer.
Claim 4
Dependent Claim
22 words
The heat-treated polymer film as recited in claim 1, wherein said solidified polymer layer is separated from said supporting body by peeling.
Claim 5
Dependent Claim
67 words
The heat-treated polymer film as recited in claim 1, wherein said process further comprises the step of: heating said solidified polymer layer, either before or after separation thereof from said supporting body, at a temperature in the range of from a minimum of about 150° C. to a maximum of about 30° C. below the thermal deformation temperature that said film had before undergoing said heating step.
Claim 6
Dependent Claim
32 words
The heat-treated polymer film as recited in claim 1, said film having a resistance to folding, as measured in accordance with JIS P8115 with an MIT tester, of at least 3000 strokes.
Claim 7
Dependent Claim
26 words
The heat-treated polymer film as recited in claim 1, said film having a tensile elongation at break as measured by JIS C2318 of at least 10%.
Claim 8
Dependent Claim
26 words
The heat-treated polymer film as recited in claim 1, said film having a degree of thickness orientation of 50 to 80% as measured by x-ray diffractometry.
Claim 9
Dependent Claim
48 words
The heat-treated polymer film as recited in claim 1, said film having a ratio between the maximum value and minimum value of penetrated microwave intensity, when irradiated with a microwave in a direction perpendicular to the film surface by the microwave transmission method, of not more than 2.
Claim 10
Dependent Claim
22 words
The heat-treated polymer film as recited in claim 1, wherein said polymer comprises monomer units derived from 6-hydroxy-2-naphthoic acid and 4-hydroxybenzoic acid.
Claim 11
Dependent Claim
19 words
The heat-treated polymer film as recited in claim 1, wherein said heating step (a) is carried out under pressure.
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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) | 2000-12-29 | 2001-06-30 | 2001-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-29 | 2005-06-30 | 2005-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-29 | 2009-06-30 | 2009-12-30 | $7700.00 | Window Closed / Lapsed |