摘要:
This invention describes compounds of formula (I) ##STR1## wherein R is C.sub.1-16 alkyl or alkoxy; X is selected from F and Cl and indicates that one or more of the phenyl rings may be laterally substituted; x is selected from 0-3; A and B are independently selected from CO.sub.2, OCO, .tbd.C and single bond; R.sub.1 and R.sub.2 are independently selected from H and C.sub.1-16 alkyl provided that R.sub.1 and R.sub.2 are different; n is 0 or 1 provided that if n is zero then B is single bond. These compounds may be used as dopants suitable for use in ferroelectric liquid crystal mixtures.
摘要:
An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
摘要:
An electoclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
摘要:
The invention describes liquid crystal compounds of formula (I) which are suitable for use in liquid crystal devices including those devices which exploit the electroclinic effect, ##STR1## where X may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.2 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.3 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; X.sub.4 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; provided that at lease one of X or X.sub.2 is CF.sub.3, CF.sub.2 H, CFH.sub.2, CN, NO.sub.2 or halogen; A and B are independently phenyl, mono-fluorinated phenyl, di-fluorinated phenyl or cyclohexyl; Y may be single bond, COO, OOC, C.dbd.C; q may be 0 or 1; R.sub.1 may be an end group of formula (II) wherein Z may be a single bond, O, CO.sub.2, (CH.sub.2).sub.n or (CH.sub.2).sub.n O where n may be 1 or 2; J and M may be independently H, C.sub.1-4 alkyl; W may be C.sub.1 -C.sub.12 straight or branched alkyl chain; R.sub.2 may contain 1-14 carbon atoms wherein one or more non-adjacent CH.sub.2 groups may be replaced by CO.sub.2 or O. X or X.sub.2 may give rise to steric hindrance with the nearest terminal group. The materials of the current invention may be mixed together and/or with other liquid crystal compounds. Suitable devices which the materials of the present invention may be incorporated in include beam steerers, piezoelectric actuators or sensors and pyroelectric sensors and displays in general. The materials of the present invention may also be useful as dopants in ferroelectrics and as second order non-linear optic materials for second harmonic conversion of light.
摘要:
An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
摘要:
Liquid crystal compounds have been synthesized of general formula (I) and may be mixed with other liquid crystal compounds to give useful liquid crystal mixtures which may then be used in liquid crystal devices. Such devices include linear and non-linear electrical, optical and electro-optical devices, magneto-optical devices and devices providing responses to stimuli such as temperature changes and total or partial pressure changes. Formula (I) where each Z.sub.1-6 is given by formula (II), where Y for each of Z.sub.1-6 is independently COO, OCO, CH.sub.2 O and OCH.sub.2, m defines the number of substituents on each of Z.sub.1-6 and is independently 0-5,and X is independently for each substituent on each of Z.sub.1-6 alkyl (straight chain, branched and chiral), alkoxy (straight chain, branched or chiral), alkanoyl (straight chain, branched or chiral), alkenyl (straight chain, branched or chiral), halogen, halogenoalkyl (straight chain, branched or chiral) and CN, provided that at least one of Z.sub.-6 1 has at least one substituent X, and excluding where m is 1 for each of Z.sub.1-6, Y is COO for each of Z.sub.1-6 and X is n-alkyl or n-alkoxy positioned para to Y for each of Z.sub.1-6 and also where M is 5 for each of Z.sub.1-6, Y is COO for each of Z.sub.1-6 and for each Z.sub.1-6 X is selected as n-alkoxy positioned para to Y and fluoride for all other substituents.
摘要:
An electro-optic color device including a layer of polymer dispersed liquid crystal (7), with polarizers on either side (9,10), at least one being colored. By applying a voltage across the polymer dispersed liquid crystal cell (PDLC), the cell is switched from a scattering to a non-scattering state or vice-versa, and the color of the transmitted light is controlled. Applications include membrane switches.
摘要:
A liquid crystal device is provided with a pair of substrates (12, 16) containing a liquid crystal material (22). A wall structure comprising, for example, a plurality of walls (14) is provided between the two substrates. The wall structure provides mechanical strength to the device and resistance to flow of liquid crystal material which can cause deterioration in the device performance. The walls may extend in two mutually different directions (FIG. 8, 40) to provide mechanical strength and resistance to flow in two directions while the device can still be readily filled. The device is particularly applicable to a ferroelectric liquid crystal device.
摘要:
In order to the effects of impact on liquid crystal devices a polymer network is introduced into ferroelectric liquid crystal cells. A liquid crystal device comprises two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, characterised in that the liquid crystal material contains a small amount of monomer. The liquid crystal material may also contain a photoinitiator. The monomer material may be cured to produce the polymer network; the curing may be carried out in the presence of an electric or magnetic field. Further, the monomer may be cured in an isotropic or liquid crystal phase.
摘要:
Liquid crystal compounds are disclosed having the formula ##STR1## where p is an integer having a value from 0 to 5 inclusive. These materials are optically active and cholesterogenic and may be used in an electro-optical display device either on their own or in admixture with nematogenic materials having a formula ##STR2## where i has a value from 0 to 5 inclusive and j is 0 or 1. These last mentioned mixtures may be thermochromic and employed in a temperature sensing device.