Abstract: This invention relates to polymer particles, a process for their preparation, the use of these particles for the preparation of an electrophoretic device, electrophoretic displays comprising such particle, and new polymerizable dyes.

Abstract: A method of fabricating a liquid crystal polymer film includes providing a support substrate having a surface having a shape arranged to define a form of a liquid crystal polymer film to be fabricated; applying a layer of a photoaligning material over the surface of the support substrate, the photoaligning material having an absorption band; exposing the layer of photoaligning material to a light having a linear polarization and the light comprising a wavelength within the absorption band to convert the layer of photoaligning material into a layer of photoaligned material; applying a layer of a polymerizable liquid crystal over the layer of photoaligned material; performing photopolymerization of the layer of polymerizable liquid crystal to form a liquid crystal polymer film; applying a solvent to the layer of photoaligned material, the solvent formulated to dissolve the photoaligned material to thereby release the liquid crystal polymer film from the support substrate; and removing the liquid crystal polymer

Abstract: To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals.

Abstract: A liquid crystalline coating solution which comprises: an azo compound represented by the following general formula (1); and a solvent to dissolve the azo compound: wherein Q1 is an aryl group which may have any substituent group; Q2 is an arylene group which may have any substituent group; R is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an acetyl group, a benzoyl group, or a phenyl group (these groups may have any substituent groups); and M is a counter ion.

Abstract: To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals.

Abstract: The present invention provides a polarizing film having a high dichroic ratio. The polarizing film of the present invention contains an azo compound represented by the following general formula (1). In the general formula (1), the OH group is attached to the naphthalene ring at an ortho position relative to the azo group attached to the ring, R1 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted acetyl group, a substituted or unsubstituted benzoyl group, or a substituted or unsubstituted phenyl group, M represents a counterion, m represents an integer of 0 to 2, n represents an integer of 0 to 6, at least one of m and n is not 0, and Q represents an anthraquinone ring having an OH group.

Abstract: Provided is an easy method for production of a high-performance polyfunctional compound which can be used as an optical recording material, an optical waveguide material, a photo-alignment film material, or the like, in a simple manner. The method for production of a polyfunctional compound includes conducting a Michael addition of a compound (A) having a hydrogen atom of pKa?15 to a (meth)acrylate or a (meth)acrylamide (B), in which at least one of the compounds (A) and (B) has a photoisomerization group and/or a liquid-crystalline group.

Abstract: Disclosed is an azo compound represented by the formula (1) below, a salt thereof, or a copper complex salt compound thereof. (In the formula, R1 and R2 independently represent a hydrogen atom, a sulfonic acid group, a lower alkyl group or a lower alkoxyl group; R3-R6 independently represent a hydrogen atom, a lower alkyl group or a lower alkoxyl group; R7 represents a lower alkyl group or a lower alkoxyl group; and n represents 0 or 1.

Abstract: Provided is an easy method for production of a high-performance polyfunctional compound which can be used as an optical recording material, an optical waveguide material, a photo-alignment film material, or the like, in a simple manner. The method for production of a polyfunctional compound includes conducting a Michael addition of a compound (A) having a hydrogen atom of pKa ?15 to a (meth)acrylate or a (meth)acrylamide (B), in which at least one of the compounds (A) and (B) has a photoisomerization group and/or a liquid-crystalline group.

Abstract: A dichroic dye composition, containing at least one kind of azo dye represented by formula (I) that has a liquid crystallinity: wherein R1, R2, R3, R4, X1 and X2 each independently represent a hydrogen atom or a substituent; A1 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted aromatic heterocyclic group; B1 is a divalent substituted or unsubstituted aromatic hydrocarbon group or a divalent substituted or unsubstituted aromatic heterocyclic group; n represents an integer of 1 to 5; and at least one of B1s represents a phenylene group having an alkyl group.

Abstract: The invention relates to light polarizers and devices for displaying information based on said polarizers, in particular to a liquid crystal indicating (LCI) element, and can be used on flat liquid-crystal displays, including those of the projection type, luminairs, optical modulators, matrix systems of light modulation, etc. The objective of the invention is to provide a highly efficient polarizer providing an improved brightness and color saturation of an LCI element based on such polarizer. This objective is to be attained by using, in manufacture of a polarizer and an LCI element based on such polarizer, at least one birefringent anisotropically absorbing layer having at least one refraction index that grows as the polarized light wavelength increases., i.e., having the abnormal dispersion. The use of said layer allows creation of polarizers of both the dichroic and interference types.

Abstract: This invention relates to a polyvinyl alcohol type polarizing film or plate which comprises a water-soluble dye having the formula (1) in a free acid form or a copper complex salt thereof.

Abstract: This invention relates to a polyvinyl alcohol type polarizing film or plate which comprises a water-soluble dye having the formula (1) in a free acid form or a copper complex salt thereof. The said polarizing plate has excellent polarizing performance capability and durability, and is suitably used for the green channel of a liquid crystal projector when B in formula (1) is a benzoylamino group and the water-soluble dye has a wavelength for maximum absorption (&lgr;max) of 520 nm or more and less than 580 nm.

Abstract: The objective of the invention is to provide an highly efficient polarizer providing an improved brightness and color saturation of a LCI element based on such polarizer. This objective is to be attained by using, in manufacture of a polarizer and a LCI element based on such polarizer, at least one birefringent anisotropically absorbing layer having at least one refraction index that grows as the polarized light wavelength increases, i.e. having the abnormal dispersion. The use of said layer allows to create polarizers of both the dichroic and interference types. Further, the use of said layer allows to create a polarizer that provides, in a relatively simple design, conversion of practically all energy of a non-polarized radiation into the polarized radiation.

Abstract: The invention relates to liquid-crystalline compounds of the formula I 1

Abstract: A dichroic azo dye characterized by having a trifluoromethyl-substituted biphenyl framework and being represented by the following general formula, and a guest-host liquid-crystal composition and a liquid-crystal display element each containing the same and having a high order parameter throughout the whole light absorption wavelength range, are provided: ##STR1## (wherein A and B each independently represents an optionally substituted alkyl group, phenyl group or cyclohexyl group; X and X.sup.1 each independently represents a methylene group or a carbonyl group; and R.sub.1 to R.sub.12 each independently represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group, or R.sub.2 and R.sub.3, R.sub.5 and R.sub.6, R.sub.8 and R.sub.9, and R.sub.11 and R.sub.12 may be bonded to each other to form an aliphatic, aromatic or nitrogenous aromatic ring which is a five-membered or larger-membered ring).

Abstract: Polarizing coatings are formed from dyestuffs which provide a stable liquid crystalline phase in a wide range of concentrations, temperatures and pH-values. Particles formed by aggregates of the liquid crystal molecules are oriented in a predetermined direction to polarize light. The stability of the liquid crystalline state allows orienting the particles by mechanical forces such as a shearing force applied when the liquid crystal (10) is spread on a support surface (20) by a knife-like doctor (90) or a tension deformation force acting on the meniscus of the liquid crystal deposited between two surfaces (20, 30) as the surfaces are peeled off one another. As a result, the polarizing coatings are formed in some embodiments by simple methods. In some embodiments, the polarizing coatings have a high lightfastness, a high thermal stability, and a high dichroic ratio.

Abstract: A dichroic dye represented by the formula (I) or (II): ##STR1## wherein the substituents are as described in the specification. The dichroic dyes (I) and (II) exhibit excellent dichroism and can be prepared from 2,2'-ditrifluoromethylbenzidine having no toxicity, such as mutagenicity.

Abstract: Disclosed is a liquid crystal monomer compound represented by formula (1): ##STR1## wherein n is an integer of from 2 to 18, X is direct bond, --(C.dbd.O)--O--, --(C.dbd.O)--NH-- or --N.dbd.N--, R.sup.1 is hydrogen or a lower alkyl group, and R.sup.2 is hydrogen, a cyano group or a methoxy group, as well as a liquid crystal polymer derived therefrom.

Abstract: Compounds containing at least one alkenyl group, at least one maleimide group and at least one rodlike mesogenic moiety are prepared by reacting one or more aminophenols containing one or more rodlike mesogenic moieties with a stoichiometric quantity of a maleic anhydride per amine group of said aminophenol and then alkenylating the resulting phenolic functional maleimide.

Abstract: A silanol compound having a mesogenic group, of the following formula (III): ##STR1## wherein each of R.sup.5 and R.sup.6, which may be the same or different, is an alkyl group or a phenyl group, X is a single bond, an oxygen atom, or a group of the formula --COO--or "OCO--, Q is a mesogenic group, and p is an integer of from 2 to 20, and a process for its production. Also disclosed are a polymerizable monomer of the following formula (I) and a polymer having repeating units of the following formula (II). ##STR2## wherein R is a hydrogen atom, a halogen atom, an alkyl group or a phenyl group, each of R.sup.1 to R.sup.6 which may be the same or different, is an alkyl group or a phenyl group, m is an integer of from 2 to 20, n is an integer of from 0 to 50, and X, Q and p are as defined above.

Abstract: Arylazo and poly(arylazo) dyes having at least one core radical selected from naphthyl or anthracyl and having at least one 2,3-dihydro-1,3-dialkyl perimidine substituent, a guest-host composition comprising a liquid crystal host solvent and the arylazo or poly(arylazo) dichroic dye, and a liquid crystal display comprising the guest-host composition, are disclosed.

Abstract: An optically active azo compound is represented by the following general formula (I), ##STR1## where R is an alkyl group having from 1 to 20 carbon atoms, and R* is an optically active radical of an alkyl group or a halogen substituted alkyl group having from 1 to 10 carbon atoms. A liquid crystal composition contains this compound. A method for producing an optically active azo compound represented by the following general formula (I) has the step of reacting a phenol compound represented by the following general formula (II) with an optically active carboxylic acid represented by the following general formula (III) using a condensing agent at a room temperature.

Abstract: Processes for preparing 2,3-dihydro-1,3-dialkyl-2,2-dialkyl perimidines and N,N'-dialkyl-1,8-naphthalene diamines are disclosed. The 2,3-dihydro-1,3-dialkyl-2,2-dialkyl perimidines are prepared by alkylating 2,3-dihydro-2,2-dialkyl perimidines with an alkylating agent in a water miscible organic solvent at room temperature to 80.degree. C. in the presence of water and an inorganic base. N,N'-dialkyl-1,8-naphthalene diamines are prepared by hydrolyzing the 2,3-dihydro-1,3-dialkyl-2,2-dialkyl perimidines with strong aqueous acid in an aqueous organic solvent and removing a ketone by-product and the aqueous organic solvent by codistillation.

Abstract: Keto compounds in which to the carbon atom in the neighboring position to the keto compounds there is bonded at least one strongly electron attracting substituent and/or in which there is conjugating with the carbon-oxygen-double bond of the keto group a .pi.-electron system have the ability of interacting selectively with the anions of oxa acids yielding adducts, chelates or complexes.Provided that in the corresponding keto compounds the keto group is a part of a chromophore, then the shifting of the absorption in the visible range or the ultraviolet range of the wave lengths is observed, compared with the corresponding absorption of the free keto compound.The corresponding keto compounds are used for the determination of the anions of the oxa acids and they e.g. can be the ion sensitive component of a corresponding ions sensitive part for the determination of said anions. Several of said keto compounds can be also used as color indicator for the anions of the oxa acids.

Abstract: A ferroelectric liquid crystal composition containing an optically active mesomorphic compound represented by the following formula (I) or (II): ##STR1## wherein R.sub.1 and R.sub.2 are respectively an alkyl, and C with * represents an asymmetric carbon atom. The mesomorphic compound provides the ferroelectric liquid crystal composition with an extended operational life in a liquid crystal device.

Abstract: A liquid crystal composition suitable for a guest-host liquid crystal device and the composition comprises a solution of a liquid crystal substance and a pleochroic dye which comprises at least one azo type compound having the formula (I), ##STR1## wherein R.sup.1 represents a hydrogen atom, an alkyl group or an alkoxy group each of which may be substituted by an alkoxy or an aryl group; a cyclohexyl group which may be substituted by an alkyl group; or --COOR.sup.3 (wherein R.sup.3 represents an alkyl group which may be substituted by an alkoxy group, a cyclohexyl group which may be substituted by an alkyl group, or an aryl group which may be substituted by an alkoxy or an alkyl group);R.sub.2 represents ##STR2## where R.sup.4 and R.sup.5 each represents an alkyl group which may be substituted by an alkoxy or an aryl group; or R.sup.4 and R.sup.5 may be connected to each other to form a ring;Z.sup.1 and Z.sup.2 each represents a hydrogen atom, a halogen atom, and alkyl group or an alkoxy group, or Z.sup.

Abstract: Trisazo dyes of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and each, independently of the others, is hydrogen, methyl, ethyl, methoxy or chlorine, R.sup.5 is C.sub.2 -C.sub.4 -alkyl, X is C.sub.1 -C.sub.24 -mono- or dialkylamino, monobenzylamino, mono-(phenyl-ethyl)-amino, monophenylamino, N-(C.sub.1 -C.sub.12 -alkyl)-N-benzylamino, N-(C.sub.1 -C.sub.12 -alkyl)-N-(phenylethyl)amino or N-(C.sub.1 -C.sub.12 -alkyl)-N-phenylamino or each of the phenyls substituted by C.sub.1 -C.sub.12 -alkyl, cyclo-hexyl, 4-(C.sub.1 -C.sub.12 -alkyl)cyclohexyl, C.sub.1 -C.sub.24 -alkyloxy, phenoxy or C.sub.1 -C.sub.24 -alkanoyloxyl, or is OR, where R is C.sub.1 -C.sub.24 -alkyl, unsubstituted or C.sub.1 -C.sub.12 -alkyl-, cyclohexyl-, 4-(C.sub.1 -C.sub.12 -alkyl)cyclohexyl-, C.sub.1 -C.sub.24 -alkoxy-, phenoxy- or C.sub.1 -C.sub.

Abstract: There are provided compounds which give quasi-liquid crystals, which comprise a mesogenic group, which can contain bridging groups, a bridging group and a spiropyran moiety having a 2H pyran ring, a terminal group being attached to the mesogenic group. The mesogenic group contains two aromatic, heterocyclic or cycloaliphatic ring structures. The compounds are prepared by a coupling reaction of mesogenic groups with a spiropyran compound via a suitable bridging group. There is provided a process for producing quasi-liquid crystalline (QLC) films which are useful for producing a wide variety of devices based on the optical non-linearity of generation of second harmonics by such films. Such devices can also be based on ferroelectric, pyroelectric, piezoelectric effects and photoactivity of such oriented QLC films.

Abstract: Liquid Crystal compounds represented by the following formula are disclosed. ##STR1## wherein R and R' are independently selected from alkyl groups containing 1.about.20 carbon atoms; X is --O--, --O--CO--O-- or direct bond; A.sub.1 and A.sub.2 are independently cyclic groups (such as phenylene and biphenylene), said cyclic groups may be substituted with 1.about.4 fluorine, chlorine or bromine atoms, or 1 or 2 substituent groups selected from the group consisting of cyano, nitro and trifluoromethyl groups; Y is --CO--O--, --O--CO--, --C.tbd.C--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.dbd.N--, --N.dbd.CH--, --N.dbd.N--, --CH.sub.2 S--, --SCH.sub.2 -- or direct bond; and * represents asymmetric atom providing optical activity.

Abstract: The new esters derived from a chiral compound containing two OH groups and at least one mesogenic carboxylic acid which have the general formula (I) ##STR1## in which X.sup.1 =O--H or O--CO--(C.sub.1 to C.sub.12)alkyl and X.sup.2 =O--MC or X.sup.1 and X.sup.2 denote O-MC independently of each other, where MC is the molecular radical of a mesogenic monocarboxylic acid after splitting off an OH group.The esters or esters substituted in the aromatic part of the phenolic part preferably find application as an admixture intwistable liquid crystal phases in which they produce a temperature compensation and a high degree of twisting.

Abstract: A dichroic dye for coloring liquid crystal compositions are disclosed which is represented by the following general formula: ##STR1## in which Dye 1 and Dye 2 each represents a group of atoms necessary to form a linear dye structure containing an azo, azomethine or ester group; X represents a halogen atom; and n represents an integer of from 1 to 10. The dye is suited for use in color liquid crystal display devices, e.g., of guest-host type.

Abstract: An optically active lactic acid derivative represented by the following formula (I): ##STR1## wherein R is a saturated or unsaturated hydrocarbon group of a linear, branched or cyclic structure having 4 to 20 carbon atoms; Ra is --CO--Rb or --CH.sub.2 --Rc wherein Rb is a releasable chemically active group, and Rc is a releasable chemically active group; and C with * represents an asymmetric carbon atom.

Abstract: Liquid crystal material containing at least one dyestuff of the formula ##STR1## in which A=the radical of an azo dyestuff,X=O or NH,R' and R"=H or C.sub.1 -C.sub.4 -alkyl, it being posible for the radicals ##STR2## to be identical or different, but these radicals preferably being --CH.sub.2 -radicals,Y=optionally substituted phenyl or optionally substituted naphthyl andn=2, 3 or 4,and new azo dyestuffs which come under the formula I.

Abstract: A novel liquid-crystalline, optically active compound exhibiting a chiral smectic phase and a chiral smectic liquid crystal composition containing the same are provided, which liquid-crystalline, optically active compound is a compound expressed by the formula ##STR1## wherein X represents a linear chain alkyl group or a linear chain alkoxy group, each of 4 to 18 carbon atoms, or a halogen atom, R* represents an optically active alkyl group of 4 to 18 carbon atoms and ##STR2## shows that the oxygen atom can be bonded to either nitrogen atom.

Abstract: A liquid crystal composition containing azo dyes represented by the formula (I.sub.0) ##STR1## wherein X represents ##STR2## A.sup.1 represents --O-- or --NH--; R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aryloxyalkyl group, a dialkylaminoalkyl group, an arylaminoalkyl group, a cycloalkyl group, an alkoxy group, an alkoxyalkoxy group, an arylalkoxy group, an aryl group, a halogen atom or a group of ##STR3## D.sup.1 and D.sup.2 each represents an aromatic group which does not contain an ionic group;U.sup.1 and U.sup.2 each represents a hydrogen atom, a halogen atom, a methyl group, a methoxy group or an ethoxy group;Y.sup.1 represents --O-- or ##STR4## R represents a hydrogen atom, an alkyl group or may be connected to Z.sup.10 to Z.sup.12 to form a ring;Z.sup.4 to Z.sup.12 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acylamino group or a cyano group, or Z.sup.4 and Z.sup.5, Z.sup.7 and Z.sup.8, and Z.sup.10 and Z.sup.

Abstract: Provided are novel dichroic azo dyestuffs, which contain skeletons represented by the following general formula: ##STR1## at one terminals of the long axes of the molecules of the azo dyestuffs, and liquid crystal compositions containing the dichroic azo dyestuffs in forms dissolved in liquid crystals. These dichroic azo dyestuffs have large dichroic ratios and high durability, and their compositions are employed as useful display devices.

Abstract: Compounds of the general formula I ##STR1## where R.sup.1 and R.sup.2 independently of one another are each C.sub.6 -C.sub.24 -alkyl or are each benzyl which is unsubstituted or substituted by alkyl or by cycloalkyl, and one of the radicals may furthermore be hydrogen, and the rings A, B, C and D can be further substituted by chlorine, methyl or methoxy, with the exception of the compound of the formula ##STR2## are useful as dyes in electrooptical liquid crystal displays or for the production of polarization films.

Abstract: Trisazo compounds of the formula ##STR1## where Z is ##STR2## X and Y independently of one another are each C.sub.1 -C.sub.24 -alkoxy, benzyloxy, phenylethoxy, mono-C.sub.1 -C.sub.24 -alkylamino, monobenzylamino, monophenylethylamino, monophenylamino, bis-C.sub.1 -C.sub.24 -alkylamino, N-C.sub.1 -C.sub.12 -alkyl-N-benzylamino, N-C.sub.1 -C.sub.12 -alkyl-N-phenylethylamino or N-C.sub.1 -C.sub.12 -alkyl-N-phenylamino, where the benzene rings are unsubstituted or substituted by C.sub.1 -C.sub.12 -alkyl, cyclohexyl, 4-C.sub.1 -C.sub.12 -alkylcyclohexyl, C.sub.1 -C.sub.24 -alkoxy, phenoxy or C.sub.1 -C.sub.24 -alkanoyloxy, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently of one another are each hydrogen, methyl, methoxy, or chlorine and R.sup.7 is hydrogen or methyl, and the ring A or B may furthermore carry a fused benzene ring, are very useful as dyes in liquid crystal media, for example for electrooptical displays.

Abstract: Novel compounds of the general formula I ##STR1## where R is hydrogen, unsubstituted or substituted alkyl, aralkyl, cycloalkyl, aryl, alkoxy, aralkoxy, cycloalkyloxy, aryloxy, alkylthio, aralkylthio or cycloalkylthio, Y is a radical of the formula ##STR2## and the rings A and B may be further substituted or fused to a benzene ring, and R.sup.1 and R.sup.2 are each hydrogen or unsubstituted or substituted alkyl, aralkyl or cycloalkyl, or together with the nitrogen atom form piperidino, pyrrolidino or morpholino, and R.sup.3 is hydrogen, alkyl, or cycloalkyl, are particularly useful as dyes in liquid-crystalline media.

Abstract: New dichroic dyestuffs for the guest-host type liquid crystal and new liquid crystal compositions containing said dyestuff having an excellent improved dichroism and being prepared by introducing at least one group selected from the group consisting of phenyl, cyclohexyl, phenylcarbonyloxy and phenyloxycarbonyl group into a phenyl, a cyclohexyl or a naphthyl group at its 4-position, which is arranged at the end of a known dichroic dyestuff molecule along the major axis of the molecule.

Abstract: A dichroic dye for use in a liquid crystal comprising at least one compound represented by a formula: ##STR1## The compound includes monoazo, disazo and trisazo compounds. The dye has a high dichroic ratio, a high mole absorptivity and a good compatibility with liquid crystals.

Abstract: Compounds of the formula ##STR1## where X is a 5-membered heterocyclic structure from the oxazole, oxadiazole, thiazole, thiadiazole, imidazole or triazole series, Y is a radical of the formula ##STR2## the rings A, B and C can be further substituted and can be fused to a benzene ring, R.sup.1 and R.sup.2 are each hydrogen or unsubstituted or substituted alkyl, aralkyl or cycloalkyl, or R.sup.1 and R.sup.2 together with the nitrogen are piperidino, pyrrolidino or morpholino, R.sup.3 is hydrogen or unsubstituted or substituted alkyl, cycloalkyl, aralkyl, acyl, alkoxycarbonyl, aryloxycarbonyl or arylsulfonyl, and R.sup.4 is hydrogen, alkyl or cycloalkyl, are particularly useful as dyes in liquid-crystalline media.

Abstract: Compounds of the general formula I ##STR1## where n is 0, 1 or 2, R.sup.1 and R.sup.2 are each hydrogen, unsubstituted or substituted alkyl, cycloalkyl, aralkyl, aryl, acyl, alkoxycarbonyl or aryloxycarbonyl, or together form alkylene or an unsubstituted or substituted benzo ring and Y is a radical of the formula ##STR2## where the rings A, B and C can be further substituted or benzo-fused, R.sup.3 and R.sup.4 are each hydrogen or unsubstituted or substituted alkyl, aralkyl or cycloalkyl, or, together with the nitrogen, form piperidino, pyrrolidino or morpholino, R.sup.5 is hydrogen, unsubstituted or substituted alkyl, cycloalkyl, aralkyl, acyl, alkoxycarbonyl, aryloxycarbonyl, alkylsulfonyl, or arylsulfonyl and R.sup.6 is hydrogen, alkyl or cycloalkyl. These compounds are useful as pleochroic dyes and have a good degree of order coupled with high solubility and good stability in the liquid crystal matrix.

Abstract: Azobarbituric acid derivatives characterized in that in their free acid form they have the following tautomeric structure are disclosed: ##STR1## The azobarbituric acid derivatives are characterized in that X and Y rings can each carry one or two substituents from the series comprising .dbd.O, .dbd.S, .dbd.NR.sub.7, --NR.sub.6 R.sub.7, --OR.sub.6, --SR.sub.6, --COOR.sub.6, --CN, --CONR.sub.6 R.sub.7, --SO.sub.2 R.sub.8, ##STR2## alkyl, cycloalkyl, aryl and aralkyl, the total number of the endocyclic and exocyclic double bonds for each of the rings X and Y being three.The new azobarbituric acid derivatives are other than those of azobarbituric acid, azouracil and uracil-5-azobarbituric acid and their salts. The compounds are useful as pigments which pigments are useful for pigmented paints, in printing inks, distempers or emulsion paints, inter alia.

Abstract: Liquid-crystal material containing an azo dyestuff of the formula ##STR1## in which X denotes H, --CN, --CF.sub.3, halogen, --OCF.sub.3, --COOR.sub.7, --OR.sub.7, --SR.sub.7, --NR.sub.7 R.sub.8 or A--N.dbd.N--,L and M denote an optionally substituted 1,4-phenylene radical or an optionally substituted 1,4-naphthylene radical,A and B denote the radical of a coupling component,R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 denote hydrogen, halogen, trifluoromethyl, nitro, alkyl, alkoxy, alkylcarbonyl, alkylthio or alkoxycarbonyl, andm and n denote 0, 1 or 2, subject to the proviso that m+n is 1 or 2,it being also possible forR.sub.7 and R.sub.8 to denote hydrogen or alkyl, cycloalkyl, aryl and aralkyl which is optionally interrupted by 1-3 non-adjacent O atoms, it being possible for the hydrocarbon radicals mentioned for R.sub.7 and R.sub.8 to be substituted and, in the case of --NR.sub.7 R.sub.

Abstract: A dichromatic coloring matter for a colored liquid crystal display element comprising a compound of the general formula: ##STR1## where A and B each stand for ##STR2## where n is 0, 1, 2, 3 or 4, and X and Y each stand for ##STR3## where R.sub.1 and R.sub.2 stand for an alkyl group or hydrogen, --R (alkyl group) or --OR (alkoxy group).

Abstract: The invention relates to liquid crystal compounds for the guest-host effect having a positive contrast, pure red color and exhibiting excellent stability. The compounds herein are derivatives of tetrazine of the general formula: ##STR1## in which m and n are 1 to 10. Other related compounds, mixtures and compositions thereof, and opto-electronic displays are described also.

Abstract: A liquid crystal composition containing azo dyes represented by the formula (I.sub.0) ##STR1## wherein X represents ##STR2## A.sup.1 represents --O-- or --NH--, R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aryloxyalkyl group, a dialkylaminoalkyl group, an arylaminoalkyl group, a cycloalkyl group, an alkoxy group, an alkoxyalkoxy group, an arylalkoxy group, an aryl group, a halogen atom or a group of ##STR3## D.sup.1 and D.sup.2 each represents an aromatic group which does not contain an ionic group; U.sup.1 and U.sup.2 each represents a hydrogen atom, a halogen atom, a methyl group, a methoxy group or an ethoxy group;Y.sup.1 represents --O-- or ##STR4## R represents a hydrogen atom, an alkyl group or may be connected to Z.sup.10 to Z.sup.12 to form a ring;Z.sup.4 to Z.sup.12 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acylamino group or a cyano group, or Z.sup.4 and Z.sup.5, Z.sup.7 and Z.sup.8, and Z.sup.10 and Z.sup.

Abstract: The description is concerned with a liquid crystal composition of the guest-host type which contains a pleochroic dye dissolved therein. The dye molecule has an end group or end groups in the molecule represented by the general formula: ##STR1## where Ro designates a straight chain of alkyl group, in which methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfer atom; R1 designates an alkyl group having a chain length different from that of the alkyl group of Ro or a group ##STR2## in R1 a methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfur atom, and R2 designates hydrogen atom, alkyl group, alkoxy group, cycloalkyl group or dialkylamino group.