US4668448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic processing of thermotropic liquid-crystalline polymers under the influence of electric fields
Assignee: Bayer AG
•
Filing: 1985-07-30
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Granted: 1987-05-26
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Expires: 2005-07-30
Abstract
Abstract The processing by shaping, in particular includes here the moulding, spinning, extrusion, compression and injection moulding of polymers. An electric field thereby influences the flowing polymer melt before and/or during and/or after shaping. The temperature of the melt is maintained at a value between the glass temperature and the isotropic point. Thermotropic liquid-crystalline polymers are used as starting product. Among these are, in principle, all polymers which have mesogenic groups in the main and/or side chain and which can be processed from the liquid-crystalline melt phase. The orientation distribution and thus also the mechanical properties of the end product can be purposefully regulated by the electric field.
Inventors
- 👤 Gunter Weber
- 👤 Hans-Rudolf Dicke
- 👤 Roland Vogelsgesang
- 👤 Walter Simm
- 👤 Hermann Brinkmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:29
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/24; B29K; B29K2067/00; B29K2995/00; B29K2995/0037; B29K2995/0041
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
A process for the production of mouldings by thermoplastic processing, by shaping, of polymers, particularly by compression, moulding, spinning, extrusion or injection moulding, wherein thermotropic liquid-crystalline polymers are used as a starting product and that an electric magnetic field is allowed to take effect on the flowing polymer melt before and/or during and/or after shaping, the temperature of which polymer melt is maintained at a value between the glass temperature and the isotropic point.
Claim 2
Dependent Claim
74 words
A process for the production of mouldings by thermoplastic processing, by shaping, of polymers, particularly by compression, moulding, spinning, extrusion or injection moulding, wherein thermotropic liquid-crystalline polymers are used as a starting product and that an electric magnetic field is allowed to take effect on the flowing polymer melt before and/or during and/or after shaping, the temperature of which polymer melt is maintained at a value between the glass temperature and the isotropic point.
Claim 3
Dependent Claim
24 words
A process according to claim 1, wherein direct or alternating electric fields take effect from 10 V/cm up to the polymer-specific breakdown field intensity.
Claim 4
Dependent Claim
25 words
A process according to claims 1 or 2, wherein those thermotropic liquid-crystalline polymers are used which have mesogenic groups in the main and/or side chain.
Claim 5
Dependent Claim
36 words
A process according to claims 1 or 2, wherein thermotropic liquid-crystalline polyesters are used which contain one or several of the following units: ##STR4## wherein R, R'and R" represent aromatic radicals of the general formula ##STR5##
Claim 6
Dependent Claim
34 words
A process according to claims 1 or 2, wherein during cooling of the moulding, the electric field is maintained until the temperature of the moulding is below the glass temperature of the corresponding material.
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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) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |