US3972589A
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Nematic liquid crystal mixtures with stable homeotropic boundary conditions and methods of making the same
Assignee: General Electric Co
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Filing: 1974-01-07
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Granted: 1976-08-03
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Expires: 1994-01-07
Abstract
Abstract Nematic liquid crystal mixtures characterized by a homeotropic boundary condition are prepared by the addition of soluble monopolar compounds to either positive or negative dielectric anisotropic nematic materials. Between approximately 0.5 and 5 percent by weight of compounds such as certain carboxylic acids, aliphatic amines and aliphatic nitriles, for example, when dissolved in a nematic material produce spontaneous homeotropic boundary conditions therein.
Inventors
- 👤 David W. Skelly
- 👤 Gordon J. Sewell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:00
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/54; C09K19/56; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133703
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
64 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and a monopolar additive selected from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles, said additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 2
Dependent Claim
64 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and a monopolar additive selected from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles, said additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 3
Dependent Claim
19 words
The mixture of claim 1 wherein said nematic liquid crystal has either a positive or a negative dielectric anisotropy.
Claim 4
Dependent Claim
49 words
The mixture of claim 1 wherein the concentration of said additive is present in a sufficient amount to produce a homeotropic boundary condition in said nematic liquid crystal when said mixture is placed between a pair of substantially parallel planar substrates spaced apart by approximately 5 to 150 microns.
Claim 5
Dependent Claim
67 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and an aliphatic mono-carboxylic acid monopolar additive having a minimum chain length of at least seven carbon atoms, said monopolar additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 6
Dependent Claim
67 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and an aliphatic mono-carboxylic acid monopolar additive having a minimum chain length of at least seven carbon atoms, said monopolar additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 7
Dependent Claim
54 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and an aliphatic nitrile monopolar additive, said monopolar additive characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 8
Dependent Claim
54 words
A nematic liquid crystal mixture characterized by a homeotropic boundary condition when formed in a thin layer, said mixture comprising a nematic liquid crystal and an aliphatic nitrile monopolar additive, said monopolar additive characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 9
Dependent Claim
102 words
A liquid crystal display device comprising: a sealed display cell having a pair of substantially parallel spaced substrates; a thin layer of a nematic liquid crystal mixture contained therebetween and in contact with an interior surface of each of said substrates; said mixture being characterized by a homeotropic boundary condition when formed in said thin layer and comprising a nematic liquid crystal and a monopolar additive selected from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles, said additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 10
Dependent Claim
102 words
A liquid crystal display device comprising: a sealed display cell having a pair of substantially parallel spaced substrates; a thin layer of a nematic liquid crystal mixture contained therebetween and in contact with an interior surface of each of said substrates; said mixture being characterized by a homeotropic boundary condition when formed in said thin layer and comprising a nematic liquid crystal and a monopolar additive selected from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles, said additive being characterized by a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 11
Dependent Claim
23 words
The liquid crystal display device of claim 6 wherein said nematic liquid crystal is characterized by a negative or a positive dielectric anisotropy.
Claim 12
Independent Claim
77 words
A method of producing a homeotropic boundary condition in a nematic liquid crystal material, said method comprising the steps of: providing a quantity of the nematic liquid crystal material; selecting a soluble monopolar compound from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles; and mixing said soluble monopolar compound into said nematic liquid crystal material in a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 13
Independent Claim
77 words
A method of producing a homeotropic boundary condition in a nematic liquid crystal material, said method comprising the steps of: providing a quantity of the nematic liquid crystal material; selecting a soluble monopolar compound from the group consisting of aliphatic mono-carboxylic acids and aliphatic nitriles; and mixing said soluble monopolar compound into said nematic liquid crystal material in a concentration of between approximately 0.5% and approximately 5% by weight thereof completely dissolving in the nematic liquid crystal.
Claim 14
Dependent Claim
104 words
In combination with a display device includng a pair of closely spaced planar substrates with a nematic liquid crystal essentially completely sealed in and filling the space therebetween and means for applying an electric field to at least selected regions of said nematic liquid crystal, the improvement comprising a monopolar additive selected from the group of aliphatic mono-carboxylic acids and aliphatic nitriles, said monopolar additive completely dissolved in said nematic liquid crystal in a concentration of between approximately 0.5% and approximately 5% by weight to cause said nematic liquid crystal to assume a homeotropic boundary condition adjacent the facing interior surface of said substrates.
Claim 15
Dependent Claim
104 words
In combination with a display device includng a pair of closely spaced planar substrates with a nematic liquid crystal essentially completely sealed in and filling the space therebetween and means for applying an electric field to at least selected regions of said nematic liquid crystal, the improvement comprising a monopolar additive selected from the group of aliphatic mono-carboxylic acids and aliphatic nitriles, said monopolar additive completely dissolved in said nematic liquid crystal in a concentration of between approximately 0.5% and approximately 5% by weight to cause said nematic liquid crystal to assume a homeotropic boundary condition adjacent the facing interior surface of said substrates.
Claim 16
Dependent Claim
24 words
The combination of claim 9 wherein said aliphatic mono-carboxylic acids and said aliphatic nitriles have a chain length of at least seven carbon atoms.
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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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |