US4447599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermotropic liquid crystal shaped article
Assignee: Imperial Chemical Industries Ltd
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Filing: 1982-04-02
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Granted: 1984-05-08
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Expires: 2002-04-02
Abstract
Abstract A method of improving the processability of rigid polymers, particularly of unprocessable rigid polymers, wherein the rigid polymer in melt or solution form is subjected to an apparent shear rate between relatively moving surfaces of at least 100 sec -1 , particularly between 100 and 1000 sec -1 . The method reduces the viscosity of the melt or solution and when the melt or solution is fabricated into shaped articles while the viscosity is so reduced the shaped articles have improved properties, particularly more uniform orientation when compared with products prepared by methods which do not include the pre-shearing step prior to fabrication.
Inventors
- 👤 Frederic N. Cogswell
- 👤 Jiri G. Tomka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:24
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3804; B; B29; B29C; B29C48/00; B29C48/022; C08; C08J; C08J5/00; C09K3/00; C09K3/24; B29C48/03; B29C48/05; B29C48/07; B29C48/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
A thermotropic liquid crystalline shaped article fabricated from a rigid polymer, said rigid polymer being in the form of a thermotropic melt, according to the method comprising improving the processability of the rigid polymer by subjecting a melt of the rigid polymer to shear between relatively moving surfaces at an apparent shear rate of at least 100 sec -1 , whereby the viscosity of the melt is reduced and remains reduced after the shear between the relatively moving surfaces ceases to be applied, and fabricating the shaped article from the melt while the viscosity is so reduced.
Claim 2
Dependent Claim
97 words
A thermotropic liquid crystalline shaped article fabricated from a rigid polymer, said rigid polymer being in the form of a thermotropic melt, according to the method comprising improving the processability of the rigid polymer by subjecting a melt of the rigid polymer to shear between relatively moving surfaces at an apparent shear rate of at least 100 sec -1 , whereby the viscosity of the melt is reduced and remains reduced after the shear between the relatively moving surfaces ceases to be applied, and fabricating the shaped article from the melt while the viscosity is so reduced.
Claim 3
Dependent Claim
49 words
A shaped article as in claim 1 wherein the rigid polymer is in the form of a thermotropic melt having an apparent viscosity of at least 100 Ns/m 2 (Newton-seconds/square meter) as calculated from the rate of throughput through a capillary and the pressure required for such a throughput.
Claim 4
Dependent Claim
61 words
A shaped article as in claim 1 wherein the rigid polymer melt has an apparent viscosity of a least 1000 Ns/M 2 (Newton-seconds/square meter) and is sheared between relatively moving surfaces at an apparent shear rate of at least 100 sec -1 , wherein said rigid polymer melt becomes a thermotropic melt as a result of being subjected to said shear.
Claim 5
Dependent Claim
35 words
A shaped article as in claim 1 wherein the rigid polymer is not in the form of a thermotropic melt prior to shearing but becomes a thermotropic melt as a result of the applied shear.
Claim 6
Dependent Claim
49 words
A shaped article as in claim 4 wherein the rigid polymer is in the form of a thermotropic melt having an apparent viscosity of at least 1000 Ns/m 2 (Newton-seconds/square meter) as calculated from the rate of throughput through a capillary and the pressure required for such a throughput.
Claim 7
Dependent Claim
87 words
A shaped article fabricated from a melt as in claim 1, 4 or 5 or wherein the rigid polymer has the repeat unit: ##STR5## in which: X is an aromatic radical selected from the group of aromatic radicals having outgoing bonds which are either colinear or parallel, and A is either an atom or a group of atoms, and assumes a configuration wherein its outgoing bonds are either parallel or form an angle θ thus: ##STR6## where θ is at least 120° and does not exceed 180°.
Claim 8
Dependent Claim
29 words
A shaped article as in claim 6 wherein between 5 mole percent and 30 mole percent of the X radicals have outgoing bonds which are neither colinear not parallel.
Claim 9
Dependent Claim
31 words
A shaped article as in claim 6 wherein greater than 10 mole percent up to 30 mole percent of the X radicals have outgoing bonds which are neither colinear not parallel.
References Cited (Backward Citations)
US3671542A
Cited
US3428602A
Cited
US3631017A
Cited
US3732349A
Cited
US4202962A
Cited
GB1507207A
Cited
US4231913A
Cited
US4093692A
Cited
US4331620A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |