US3984343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal mixtures with selectively variable dielectric anisotropies
Assignee: LXD Inc
•
Filing: 1974-05-01
•
Granted: 1976-10-05
•
Expires: 1994-05-01
Abstract
Abstract Nematic liquid crystal mixtures characterized by a selectively variable anisotropy and a mesophase including room temperatures are described. The mixtures comprise a negative dielectric anisotropic nematic liquid crystal material and a small percentage of a positive dielectric anisotropic nematic liquid crystal present in an amount effective to increase the dielectric anisotropy of the mixture. The further addition of a small percentage of a cholesteric material produces a mixture characterized by a helicoidal structure having a pitch greater than the wavelength of visible light and a cholesteric-nematic transition phenomenon induced by an electric field.
Inventors
- 👤 Herbert S. Cole, Jr.
- 👤 Richard A. Kashnow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:43
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
A liquid crystal mixture exhibiting light scattering in a field free condition and substantial transparency in a field applied condition, said mixture comprising: a negative dielectric anisotropic nematic liquid crystal material consisting of n-(p-methoxybenzylidene)-p-butylaniline(MBBA); a positive dielectric anisotropic nematic liquid crystal material selected from the group consisting of p-[p-(methoxybenzylidene)-amino] benzonitrile and n-(p-ethoxy-benzylidene)-amino benzonitrile, said material being present in an effective amount to increase in a positive sense the dielectric anisotropy of said mixture to a value above zero; and a cholesteric liquid crystal, said cholesteric liquid crystal present in a concentration between approximately 2 and 10% by weight.
Claim 2
Dependent Claim
98 words
A liquid crystal mixture exhibiting light scattering in a field free condition and substantial transparency in a field applied condition, said mixture comprising: a negative dielectric anisotropic nematic liquid crystal material consisting of n-(p-methoxybenzylidene)-p-butylaniline(MBBA); a positive dielectric anisotropic nematic liquid crystal material selected from the group consisting of p-[p-(methoxybenzylidene)-amino] benzonitrile and n-(p-ethoxy-benzylidene)-amino benzonitrile, said material being present in an effective amount to increase in a positive sense the dielectric anisotropy of said mixture to a value above zero; and a cholesteric liquid crystal, said cholesteric liquid crystal present in a concentration between approximately 2 and 10% by weight.
Claim 3
Dependent Claim
26 words
The liquid crystal mixture of claim 1 wherein said positive dielectric anisotropic material is present in a concentration between approximately two and twenty percent by weight.
Claim 4
Dependent Claim
23 words
The liquid crystal mixture of claim 2 wherein said composition is further characterized by a pitch greater than the wavelength of visible light.
Claim 5
Dependent Claim
49 words
The liquid crystal mixture of claim 1 wherein a thin layer of said composition is characterized by a helicoidal structure having a pitch which causes visible light incident on said layer to be scattered with an angular distribution which is substantially independent of the wavelength of the visible light.
Claim 6
Dependent Claim
29 words
The liquid crystal mixture of claim 4 wherein said thin layer is rendered substantially transparent when an electric field of approximately 10 6 volts/meter is applied to said layer.
References Cited (Backward Citations)
US3322485A
Cited
US3499702A
Cited
US3650603A
Cited
US3781088A
Cited
US3815972A
Cited
US3891307A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-05 | 1980-04-05 | 1980-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-05 | 1984-04-05 | 1984-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-05 | 1988-04-05 | 1988-10-05 | $7700.00 | Window Closed / Lapsed |