Liquid crystal compound and liquid crystal composition including the same
申请人:HITACHI, LTD.
公开号:EP0162437A2
公开(公告)日:1985-11-27
A liquid crystal compound of the formula:
wherein
R2 is preferably C7-14 alkyl;
X1 is -COO- or -OCO;
Y1 is
Y2 is
; and
Z is -N02 or -CN, shows a smectic phase, is large in positive dielectric anisotropy and can give a liquid crystal composition (5) suitable for use in a thermal address display device.
A liquid crystal compostion for use in a thermal writing liquid crystal display utilizing a thermo-optical effect, and a liquid crystal display element using same are disclosed. The liquid crystal composition has an extremely narrow nematic range and a phase transition of a low melting point, and is used for a liquid crystal display element The liquid crystal composition contains at least two components, i.e., component A comprising at least one 4-n-alkyl-4'-cyanobiphenyl represented by general formula (I) wherein R' represents an alkyl group having 8, 9. 10.11.12 carbon atoms) and component B comprising at least one 4-n-alkoxycarbonyloxy-4'-cyanobiphenyl represented by general formula (II) wherein R2 represents an alkyl group having 8. 9. 10. 11 or 12 carbon atoms), in a ratio of component A to component B of 25:75 to 95:5. Since the composition may have a nematic range of 2°C or below, it enables rapid writing on a display element and improves the contrast of a projected image. thus markedly improving display quality Additionally, it is advantageously used for a thermal writing liquid crystal display to be used at room temperature since it has a melting point of 0 C or below
Achiral fluorine-containing liquid crystal compounds are provided. The compounds comprise a fluorocarbon terminal portion and a hydrocarbon or another fluorocarbon terminal portion, the terminal portions being connected by a central core, the compounds having smectic mesophases or having latent smectic mesophases. The compounds are useful in liquid crystal display devices both alone and in mixtures with other materials. Also provided is a process for preparing these compounds.
Disclosed is a process for aligning the molecules in a liquid crystal medium having a surface adjacent to a substrate, in which the liquid crystals have a molecular weight of less than 1500, and anisotropically absorbing molecules in the medium or in the substrate adjacent to it are exposed to linearly polarized light of a wavelength within the absorption band of the absorbing molecules, and alignment of the liquid crystal medium at an angle + or - ϑ with respect to the direction of the linear polarization of the incident light beam is induced by the exposed anisotropically absorbing molecules.
Process for the preparation of NiNi-dialkyl-1,8-naphthalene diamine
申请人:HERCULES INCORPORATED
公开号:EP0406812A2
公开(公告)日:1991-01-09
A process for making 2,3-dihydro-1,3-dialkyl-2,2-dialkyl perimidines, their use for preparing polyazo arylazo and poly(arylazo) dichroic dyes having a 2,3-dihydro perimidine substituent, and the use of such dyes in guest-host liquid crystal mixtures are disclosed.