US5354489A
Expired / Lapsed
US
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Method for changing the viscosity of a fluid comprising a liquid crystal compound
Assignee: Asahi Kasei Corp
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Filing: 1991-08-28
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Granted: 1994-10-11
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Expires: 2011-08-28
Abstract
Abstract A homogeneous electrorheological fluid is disclosed, which mainly comprises a liquid crystal compound in which a plurality of liquid crystal groups are bonded to a molecular chain either directly or via a spacer, or comprises a lyotropic liquid crystal comprising a solute and a solvent. The electrorheological fluid exhibits higher electrorheological effects as well as high response rate and low power driving properties while being free from sedimentation or flocculation.
Inventors
- 👤 Akio Inoue
- 👤 Syunji Maniwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:44
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/40; C09K19/406; C09K19/408; C10; C10M; C10M171/00; C10M171/001
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
61 words
A method for changing the viscosity of a fluid of a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer, which comprises applying a voltage to said liquid crystal compound under a shear rate within a temperature range where said liquid crystal compound exhibits a liquid crystal phase.
Claim 2
Independent Claim
61 words
A method for changing the viscosity of a fluid of a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer, which comprises applying a voltage to said liquid crystal compound under a shear rate within a temperature range where said liquid crystal compound exhibits a liquid crystal phase.
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein said molecular chain is a flexible molecular chain.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein an oligomer or polymer of a unit composing said molecular chain has a glass transition temperature of not higher than room temperature.
Claim 5
Dependent Claim
16 words
The method of claim 3, wherein said glass transition temperature is not higher than 0° C.
Claim 6
Dependent Claim
21 words
The method of claim 2, wherein said flexible molecular chain comprises a siloxane unit, an alkylene unit, or an oxyalkylene unit.
Claim 7
Dependent Claim
15 words
The method of claim 1, wherein said liquid crystal group has a positive dielectric anisotropy.
Claim 8
Dependent Claim
15 words
The method of claim 1, wherein said liquid crystal compound forms a smectic crystal phase.
Claim 9
Dependent Claim
29 words
The method of claim 1, wherein the length of the longest spacer is twice or more as long as the length of the shortest spacer per liquid crystal compound.
Claim 10
Dependent Claim
37 words
The method of claim 1, wherein said fluid comprises a mixture of said liquid crystal compounds each having spacers of different length such that the maximum length is twice or more as long as the minimum length.
Claim 11
Dependent Claim
29 words
The method of claim 1, wherein said fluid comprises a mixture of said liquid crystal compound and a liquid crystal compound having one liquid crystal group in a molecule.
Claim 12
Dependent Claim
34 words
The method of claim 1, wherein said fluid consists essentially of a dispersion with liquid crystal properties of said liquid crystal compound in a dispersion medium which exhibits no liquid crystal properties by itself.
Claim 13
Dependent Claim
19 words
The method of claim 11, wherein both of said molecular chain and said dispersion medium have a siloxane unit.
Claim 14
Dependent Claim
29 words
The method of claim 1, wherein said fluid contains from 0.01 to 10% by volume of insulating spherical particles having a particle size off from 1 to 100 μm.
Claim 15
Dependent Claim
18 words
The method of claim 1, wherein said liquid crystal compound is selected from the group consisting of: ##STR18##
Claim 16
Dependent Claim
17 words
The method of claim 1, wherein said voltage is an alternating voltage or a direct pulsating voltage.
Claim 17
Dependent Claim
15 words
The method of claim 1, wherein said shear rate is 100 sec -1 or more.
Claim 18
Dependent Claim
47 words
In an actuator comprising electrodes and an electrorheological liquid being located between said electrodes, the improvement wherein said electrorheological fluid is a fluid of a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer.
Claim 19
Dependent Claim
47 words
In an actuator comprising electrodes and an electrorheological liquid being located between said electrodes, the improvement wherein said electrorheological fluid is a fluid of a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer.
Claim 20
Independent Claim
55 words
A method for changing the viscosity of a homogeneous electrorheological fluid comprising a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer, which comprises application of an alternating voltage or a direct pulsating voltage under a shear rate to said electrorheological fluid.
Claim 21
Independent Claim
55 words
A method for changing the viscosity of a homogeneous electrorheological fluid comprising a liquid crystal compound comprising a molecular chain having at least two liquid crystal groups bonded thereto either directly or via a spacer, which comprises application of an alternating voltage or a direct pulsating voltage under a shear rate to said electrorheological fluid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |