US4285829A
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Liquid-crystalline dielectric
Assignee: Merck Patent GmbH
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Filing: 1979-07-20
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Granted: 1981-08-25
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Expires: 1999-07-20
Abstract
Abstract A liquid-crystalline dielectric having a positive dielectric anisotropy comprises a biphenyl derivative of the formula ##STR1## wherein R 1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and a phenylcyclohexane derivative of the formula ##STR2## wherein R 2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3.
Inventors
- 👤 Rudolf Eidenschink
- 👤 Ludwig Pohl
- 👤 Georg Weber
- 👤 Fernando Del Pino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:20
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/44
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
A liquid-crystalline dielectric having a positive dielectric anisotropy comprising at least one biphenyl derivative of the formula ##STR6## wherein R 1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and at least one phenylcyclohexane derivative of the formula ##STR7## wherein R 2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3, said dielectric containing at least four of said biphenyl and phenylcyclohexane derivatives combined.
Claim 2
Dependent Claim
73 words
A liquid-crystalline dielectric having a positive dielectric anisotropy comprising at least one biphenyl derivative of the formula ##STR6## wherein R 1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and at least one phenylcyclohexane derivative of the formula ##STR7## wherein R 2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3, said dielectric containing at least four of said biphenyl and phenylcyclohexane derivatives combined.
Claim 3
Dependent Claim
116 words
A liquid-crystalline dielectric having a positive dielectric anisotropy comprising at least one biphenyl derivative of the formula ##STR8## wherein R 1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and at least one phenylcyclohexane derivative of the formula ##STR9## wherein R 2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3, and further comprising a cyclohexane derivative of the formula ##STR10## wherein the ring A is 1,4-disubstituted phenyl or cyclohexane and R 3 and R 4 are each straight-chain alkyl of 1-8 C; or, if ring A is phenyl, R 4 is also alkoxy or alkanoyloxy, of up to 8 C atoms in each case, or CN.
Claim 4
Dependent Claim
116 words
A liquid-crystalline dielectric having a positive dielectric anisotropy comprising at least one biphenyl derivative of the formula ##STR8## wherein R 1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and at least one phenylcyclohexane derivative of the formula ##STR9## wherein R 2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3, and further comprising a cyclohexane derivative of the formula ##STR10## wherein the ring A is 1,4-disubstituted phenyl or cyclohexane and R 3 and R 4 are each straight-chain alkyl of 1-8 C; or, if ring A is phenyl, R 4 is also alkoxy or alkanoyloxy, of up to 8 C atoms in each case, or CN.
Claim 5
Dependent Claim
16 words
The liquid-crystalline dielectric of claim 1 or 2, wherein the weight ratio is 2:1 to 1:2.
Claim 6
Dependent Claim
22 words
The liquid-crystalline dielectric of claim 1 or 2, containing at least 55 percent by weight of the biphenyl and phenylcyclohexane derivatives combined.
Claim 7
Dependent Claim
22 words
In a liquid-crystal display element comprising a liquid-crystalline dielectric composition, the improvement wherein the liquid-crystalline dielectric composition is that of claim 1.
Claim 8
Dependent Claim
22 words
In a liquid-crystal display element comprising a liquid-crystalline dielectric composition, the improvement wherein the liquid-crystalline dielectric composition is that of claim 2.
Claim 9
Dependent Claim
18 words
The liquid crystalline dielectric of claim 1 containing four or five of the biphenyl and phenylcyclohexane derivatives combined.
Claim 10
Dependent Claim
16 words
The liquid crystalline dielectric of claim 1 containing four of the biphenyl and phenylcyclohexane derivatives combined.
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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) | 1984-08-24 | 1985-02-23 | 1985-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-24 | 1989-02-23 | 1989-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-24 | 1993-02-23 | 1993-08-25 | $7700.00 | Window Closed / Lapsed |