Home

Primary Examiner: Padgett, Benjamin R.
Assistant Examiner: Gron, T. S.
Attorney: Oblon, Fisher, Spivak, McClelland & Maier

Next ten patents ordered by date:

Capsular products
Catalyst for disproportionation of toluene
Gelatinous fragrance-imparting composition containing stabilized perfume
Powdered detergent compositions containing a calcium salt of an anionic surfactant
Polymer-inorganic foam
Fire-retardant composition
Crosslinked hydrophilic foams and method
Cyclic phosphonite stabilized cellulose ester compositions
Method of synthesizing polyvinyl chloride compositions
Cationic method for emulsifying asphalt-rubber paving material and a stable thixotropic emulsion of said material

Translate:
En
De
Es
Fr
It
Pt
Ja
Ko
Zh

Title: Utilization of dyes for liquid crystal displays

Abstract: In a cholesteric guest-host liquid crystal composition having a positive dielectric anisotropy and consisting of a nematic host component with a dye incorporated as a guest component therein and an optically active (cholesteric) component, the improvement consisting of a substantially stable and water insoluble azo dye guest component having a pleochroic ratio a.sub.1 /a.sub.2 of at least 6.5 and an absorption maximum in the range of from 350 to 700 nm, said azo dye being a compound of the formula (1) X -- A -- N .dbd. N -- B -- Y (I) wherein A is selected from the group consisting of 1,4-phenylene, 2-hydroxy-1,4-naphthylene and 2-hydroxy-8-amino-1,4-naphthylene; B is selected from the group consisting of 1,4-phenylene, 1,5-naphthylene and 5-substituted benzothiazo-(1,3)-2-yl; X is selected from the group consisting of nitro, nitrile, dimethylamino, di(hydroxyethyl)-amino, phenyl and straight chain C.sub.1 -C.sub.10 alkyl, and Y is a monovalent organic radical that does not promote water solubility in the dye molecule.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Osman, Maged A. (Zurich, CH)
Scheffer, Terry J. (Forch, CH)

Application Number: 809276
Filing Date: 1977-06-23
Publication_date: 1979-01-30
Assignee: BBC Brown, Boveri & Company, Limited (Baden, CH)
Primary Class(es): 252/299.1 252/299.5
Other Classes:
US Patent Ref:

3597044	Aug, 1971	Castellano	252/299.
3703329	Nov, 1972	Castellano	252/299.
3833287	Sep, 1974	Taylor et al.	252/299.
3864022	Feb, 1975	Moriyama et al.	252/299.
3960750	Jun, 1976	Moriyama et al.	252/299.
3960751	Jun, 1976	Moriyama et al.	252/299.
4032219	Jun, 1977	Constant et al.	252/299.
4032470	Jun, 1977	Bloom et al.	252/299.
4048088	Sep, 1977	Yaguchi et al.	252/299.

Other Refs: 26272151459046

Jan, 1977	DE
Dec, 1976	GB

Other References: White, D. L., et al, J. Appl. Phys., vol. 45, No. 11, pp. 4718-4723 (1974).
Blinov, L. M., et al., J. Phys. (Paris), vol. 36, C-1, No. 3, pp. 69-76 (1975).
Bloom, A., et al., Mol. Cryst. Liq. Cryst., vol. 40, pp. 213-221 (1977).
Bloom, A., et al., Mol. Cryst. Liq. Cryst., vol. 41, pp. 1-4 (Aug. 1977).