Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electrooptical system. The electrooptical system comprises a PDLC film comprising a liquid crystal mixture forming micro- droplets in an optically isotropic, transparent polymer matrix between 2 electrode layers, one of the refractive indices of the liquid crystal mixture is matched to the refractive index of the polymer matrix, the PDLC film exhibits an electrically switching transparency essentially independent of the polarization of the incident light, the precursor of the PDLC film comprises one or more monomers, oligomers and/or prepolymers and a photoinitiator, and is cured photoradically, the liquid crystal mixture comprises one or more compounds of the formula I  wherein R, A1, A2, Z1, Z2, X1, X2, Q, Y and n are as defined herein.

Abstract: The present invention provides a photopolymerizable liquid crystal monomer having high durability, a low melting point and an enantiotropic property. The photopolymerizable liquid crystal monomer is a 4-(4-(alkyloxycarbonyloxy)benzoyloxy)phenyl acrylate represented by the following formula A [wherein Ph is a 1,4-phenylene group, and R is an alkyl group]: CH2═CHCOO—Ph—OCO—Ph—OCOO—R  Formula A Further, the present invention provides a polymer liquid crystal obtained by polymerizing a composition containing the monomer. Further, the present invention provides an optical element employing the polymer liquid crystal, and an optical head employing the optical element as a polarizing hologram element.

Abstract: The invention relates to a polymerizable liquid crystal material containing at least one polymerizable surface-active compound, its use for the preparation of anisotropic polymer films, and the use of the liquid crystal material and the polymer films in optical and electrooptical devices, and for decorative and security applications.

Abstract: The invention relates to compounds of formula I 1

Abstract: The invention relates to esters of the formula I and to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it comprises one or more compounds of the general formula I in which R, A1, Z1, L1, L2, Y and n are as defined in herein.

Abstract: The invention relates to a thermochromic liquid crystalline medium comprising a liquid crystalline host component and an active component, to a thermochromic ink comprising such a thermochromic liquid crystalline medium encapsulated in a light transmissive polymeric material, to the use of a thermochromic medium or ink in decorative applications like pigments, inks and paints, cosmetics, thermodiagnostic applications like medical thermography, thermometry, optical and electrooptical applications, and security applications and devices, to a security marking or device comprising a thermochromic liquid crystalline medium or thermochromic ink and to a document of value comprising such a security marking.

Abstract: A liquid crystal polyester resin mixture having a stabilized plastication time and accordingly possible to be molded in constant cycles and giving a molded article excellent in mechanical properties and thermal stability is provided. The liquid crystal polyester resin mixture comprises 100 parts by weight of a liquid crystal polyester resin composition which comprises 100 parts by weight of a liquid crystal polyester and from 0 to 150 parts by weight of a filler, and either from 0.001 to 5 parts by weight of a fatty acid amide having a formula; R1—CO—NH2 (wherein R1 denotes a saturated or unsaturated hydrocarbon of 10 to 30 carbons) or from 0.001 to 2 parts by weight of a high molecular weight polyethylene with a molecular weight of 10,000 or higher.

Abstract: An object of the present invention is to provide a polymerizable liquid crystal composition incorporating a polymerizable liquid crystal compound which displays a low nematic phase temperature, displays excellent compatibility with other polymerizable liquid crystal compounds, and furthermore yields a product following polymerization, of good transparency and high mechanical strength.

Abstract: The invention relates to chiral compounds of formula I, 1

Abstract: Polymerizable tolanes of formula I wherein P, Sp, X, n, A1, A2, Z1, Z2, m1, m2, L1, L2, r and R have the meanings defined herein, polymerizable liquid crystal compositions comprising at least one compound of formula I, linear or crosslinked liquid crystal polymers obtainable from these compounds and compositions, are suitable for use in optical elements such as polarizers, retardation and compensation films, alignment layers, color filters or holographic elements. They are also suitable for use in liquid crystal displays such as PDLC, polymer gel or polymer stabilized cholesteric texture (PSCT) displays, as well as for use in adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics or liquid crystal pigments, for decorative and security applications, and for nonlinear optics or optical information storage.

Abstract: The invention provides LC compositions that exhibit V-shaped switching when aligned in an analog device configuration and exhibit bistability when aligned in a bookshelf-type device configuration. The invention more specifically provides LC compositions of formula 1 and particularly chiral nonracemic compounds of formula 1 which exhibit bistable switching as well as V-shaped switching when aligned in appropriate device configurations. The invention also provides methods of using the compounds of the invention in making LC compositions and electooptical devices comprising an aligned layer of the compositions of this invention.

Abstract: Chiral nonracemic, chiral racemic and achiral compounds useful as component of LC compositions which have a silane tail group which is partially fluorinated. The silane tail group comprises a perfluoroalkyl group.

Abstract: Compounds that are useful as components in liquid crystal compositions, particularly in ferroelectric liquid crystal compositions. Compounds of the invention are rod-like molecules with a mesogenic (generally linear) core to which an alkene tail and an alkyl or alkoxy tail with a perfluoroalkyl terminal portion are bonded. Compounds of the invention can contain a variety of one, two or three ring cores, wherein the rings maybe aromatic or alicyclic. Alkenes of the invention are useful as components to improve LC properties of mixtures, for example, to lower melting point of lower freezing point, of LC compositions.

Abstract: The invention relates to chiral compounds of formula I wherein R1, R2, X, Y1 and Y2 have the meanings defined herein, as well as to liquid crystalline mixtures comprising at least one chiral compound of formula I.

Abstract: The invention relates to monoreactive mesogenic compounds of formula I wherein P, Sp, X, n, Y1, Y2, r1, r2, r3, Z1 and Z2 are defined herein.

Abstract: An active matrix display comprises a chiral smectic liquid crystal mixture which has the phase sequence I—N*—SmC*, a spontaneous polarization in the operating temperature range of <40 nC/cm2 and a pitch of >10 &mgr;m at at least one temperature in the nematic or cholesteric phase and comprises at least one compound each from at least two of the substance classes (A), (B) and (C) and one or more compounds from substance class (D): (A): compounds comprising two rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle; (B): compounds comprising three rings selected from phenylene-1,4-diyl, two of the rings being directly linked to one another and the third ring being linked to one of the other two rings via an —OC(═O)— or —C(═O)—group, with the proviso that at least one of the three rings is

Abstract: Optically active compounds of the following general formula (1) useful as chiral dopant, 1

Abstract: A chiral nematic liquid composition, which exhibits a cholesteric phase at a room temperature, comprising a nematic liquid crystal composition and at least one kind of chiral agent. The nematic liquid crystal composition includes at least one kind of liquid crystal ester compound, at least one kind of liquid crystal terphenyl compound, and at least one kind of liquid crystal tolane compound. This chiral nematic liquid crystal offers superior bidirectional stability, good color purity and reflectance, high contrast, a wide temperature compensation range, and a low voltage driving requirement.

Abstract: Liquid-crystalline media comprising one or more compounds of formula A 1

Abstract: The invention relates to a one-step process for the preparation of acryloyl group-containing liquid-crystalline monomers of the general formula (1) (Z—Y1—A2—Y2—)mM(—O—A1-acrylate)n  (1) in which mesogenic alcohols of the general formula (2) (Z—Y1—A2—Y2—)mM(OH)n  (2) are reacted with esters of 3-chloropropionic acid of the general formula (3) ClPr—A1—X  (3) with elimination of HCl, where acrylate is an acrylate radical, ClPr is a 3-chloropropionate radical, A1 are identical or different alkyl chain spacers having 2-20 carbon atoms, in which the carbon chain may be interrupted by non-adjacent ether, thioether, or imino groups, A2 are radicals A1 or single chemical bonds, M is a mesogenic group, X is a leaving group, Z are alkyl radicals or crosslinkable groups, Y1 and Y2, independently of one another, are a single chemical bond, —O—, —S—, —O—CO—, —CO

Abstract: A liquid-crystal medium comprising a) at least one compound of the formula I and b) at least one compound of the formula II 1

Abstract: The invention relates to a process for the preparation of melt processable liquid crystalline terpolyesters of the general formula I by the in situ acetylation of a monomer selected from (4-hydroxyphenyl) acetic acid/ 3(4-hydroxyphenyl)propionic acid and hydroquinone/4,4′-biphenol/2,6-naphthylene diol followed by acidolysis polycondensation with or without a solvent and a catalyst, under reduced pressure for the efficient removal of acetic acid to effect higher molecular weight formation. Post polymerisation is effected at higher temperatures below the decomposition temperature purification by soxhlet extraction using solvent mixtures selected from acetone-alcohol, acetone-methylethyl ketone.

Abstract: There are disclosed amphoteric nano-sized metal oxide particles functionalized with silyl esters of a phosphonate and composites thereof with an acrylate-based monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Also disclosed are the method making such functionalized particular by reacting a metal oxide with a silyl ester of a phosphonate in the presence of a non-aqueous solvent and in an inert atmosphere and the method of making the composites wherein the functionalized particles are admixed with an acrylate-based matrix monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Further disclosed is the method of dental repair wherein the composites are applied to a tooth and photopolymerized.

Abstract: Liquid crystalline compounds are disclosed which have large dielectric anisotropy and relatively low viscosity, and which are represented by formula (1) 1

Abstract: Compounds with the general formula (I): R—S1—A—Z1—B—S2—R, where A and B are independent ring systems with the formulae (a1), (a2) or (b), whereby in the trans-1,4-cyclohexylene ring, one or two non-adjacent CH2 groups may be replaced by oxygen, and whereby, in the 1,4-phenylene ring, one or two non-adjacent CH groups may be replaced by nitrogen; L1, L2, L3 represent, independently, hydrogen, C1-C20-alkyl, C1-C20-alkenyl, C1-C20-alkyloxy, C1-C20-alkyloxy carbonyl, formyl, C1C20-alkyl carbonyl, C1-C20-alkyl carbonyloxy, halogen, cyano or nitro; Z1, Z2, Z3 represent, independently, a single bond, —CH2CH2—, —CH2O—, —OCH2—, —COO—, —OOC—, —(CH2)4—, —O(CH2)3—, —(CH2)3O— or —C≡C—; S1, S2 represent a spacer unit; R represents crosslinkable groups, with the proviso that at least one of the ring systems A or B represents a ring system with the formula (a1

Abstract: A polymerizable compound represented by formula (I): 1

Abstract: Nematic liquid-crystal compositions of negative dielectric anisotropy comprising compounds of the formula I are useful in plasma-addressed liquid-crystal displays.

Abstract: Disclosed are polymerizable liquid-crystalline compounds of the general formula (I) 1

Abstract: There is disclosed a liquid crystalline polyacetylene having a repeat structure of the formula 1

Abstract: The present invention relates to liquid-crystalline compositions of matter comprising, as components,

Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it comprises one or more compounds of the general formula I 1

Abstract: An objective of the present invention is to provide a liquid crystal composition whose orientation undergoes a large change upon irradiation with light, and which also has a large birefringence &Dgr;n. The liquid crystal composition contains an aromatic acetylene compound and a chiral compound that undergoes a structural change upon photoreaction, and has such properties that, upon irradiation with light, its helical pitch undergoes a large change in accordance with the level of the light intensity, and that has a large birefringence &Dgr;n. Therefore, the present invention makes it possible to provide a reflection type color filter which utilizes the liquid crystal composition, and which provides a lighter display with high reflectance. Moreover, the present invention also provides an optical film that can be formed as a thinner film using the liquid crystal composition.

Abstract: A liquid crystal display which carries out matrix driving of a chiral nematic liquid crystal composition, which is capable of displaying an image theron continuously after a turn-off of an electric field applied thereto, by applying an electric field to the liquid crystal composition through a plurality of scan electrodes and a plurality of data electrodes which face and cross each other with the liquid crystal composition in-between. The nematic liquid crystal which is the main element of the liquid crystal composition mainly contains a liquid crystalline ester compound, a liquid crystalline stilbene compound, a liquid crystalline tarphenyl compound or a liquid crystalline tolane compound.

Abstract: The invention relates to an electrooptical liquid-crystal display having a realignment layer for realigning the liquid crystals, where the field thereof has a significant component parallel to the liquid-crystal layer, containing a liquid-crystalline medium having positive dielectric anisotropy, where the medium comprises at least one mesogenic compound which contains a group of the formula I and at least one compound of formula II wherein L1 is H or F; R1 R2 are H, an alkyl or alkenyl radical having 1 to 15 carbon atoms which may be substituted; Q is a radical of the formula —(O)q (CH2)r—(CF2)s— in which q is 0 or 1; r is 0 or an integer of 1 to 6, and s is an integer of 0 to 6; X is F or Cl, and in the case where s ≠0, is alternatively H, and A1 and A2 are each, independently of one another, a 1,4-cyclohexenylene or trans-1,4-cyclohexylene which may be substituted; 1,4-phenylene in which may be substituted, 1,4-bicyclo[2.2.

Abstract: The invention relates to chiral compounds of formula I 1

Abstract: 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.

Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2 are independently (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by -O- and/or -S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2O—,—OCH2—, —CH2CH2—, —CH═CH—,—C≡C—or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the provisos that at least one of the radicals A1 and A2 present in the molecule is  and at least one of Z1 or Z2 is —COO—, are suitable as components of liquid-

Abstract: Liquid crystalline compounds having a comparatively high voltage holding ratio, high &Dgr;n and high &Dgr;&egr;, and excellent miscibility with known liquid crystalline compounds at low temperatures.

Abstract: An optically anisotropic film obtained from a mixture comprising a polymer and a liquid crystal compound, wherein retardation of the optically anisotropic film at 80° C., 60° C. or 0° C. measured from a normal direction is 20-97%, 20-99% or 101-150%, respectively, of retardation at 30° C., and an absolute value of a deviation in retardation by said liquid crystal compound is not greater than 6% when the optically anisotropic film is held at 30% for 200 hours, has the temperature dependence in accordance with the temperature dependence of retardation of a liquid crystal display cell, and a small variation of retardation by the liquid crystal compound with the lapse of time, and thus is suitable for use in a liquid crystal display apparatus.

Abstract: A new class of mesogenic compounds has the formula: where R1 is an ester (—COO—) group; R2 is H, NO2, CN, F, or Cl; R3 is H, CH2═CH, or (CH3)3Si; k is 1 or 2; q is 0 or 1; m is from 2 to 16; n is from 2 to 12; r is from 0 to n−1 (but not greater than 3 or 4); s=1 when r=0, s=0 when r≠0; x is from 0 to 4; and * denotes the position of a chiral carbon. Compounds within this class will have a smectic A* phase, and in some cases a smectic C* phase. Mixtures including one or more of these mesogenic compounds will be useful for a variety of applications.

Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electroptical system.

Abstract: An antiferroelectric liquid crystal composition having a chiral smectic CA* phase composed by blending liquid crystal composition-constituting compounds having the same direction of inclination of optic axis produced by application of an electric field and/or comprised of a mixture of two enantiomers of a liquid crystal material; one having the stereosense (+) and the other having the stereosense (−). The stereosense is defined so that, when the molecule is viewed so that the bond between the core group and the asymmetric carbon is behind the asymmetric carbon atom, the stereosense is (+) if the remaining three groups (or atoms) are arranged clockwise in order of length of the groups (or, if the groups are the same length, in order of their volume), and the stereosense is (−) if the groups are arranged counter clockwise.

Abstract: There are disclosed amphoteric nano-sized metal oxide particles functionalized with silyl esters of a phosphonate and composites thereof with an acrylate-based monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Also disclosed are the method making such functionalized particular by reacting a metal oxide with a silyl ester of a phosphonate in the presence of a non-aqueous solvent and in an inert atmosphere and the method of making the composites wherein the functionalized particles are admixed with an acrylate-based matrix monomer, including liquid crystal monomers photopolymerizable at ambient temperature. Further disclosed is the method of dental repair wherein the composites are applied to a tooth and photopolymerized.

Abstract: A fluorine-substituted compound of the following general formula (1) or (2), and a ferrielectric liquid crystal composition comprising the above compound and a specific ferrielectric liquid crystal compound, wherein, in the formula (1), each of X1 and X2 is a hydrogen atom, or one of them is a hydrogen atom and the other is a fluorine atom, p is an integer of 0 to 3 and q is an integer of 1 to 3, and in the formula (2), each of X1 and x2 is a hydrogen atom, or one of them is a hydrogen atom and the other is a fluorine atom, p is an integer of 1 to 3 and q is an integer of 1 to 3.

Abstract: An anti-ferroelectric liquid crystal composition containing a phenyl triester compound of the formula (1), wherein R1 is a linear alkyl group having 6 to 12 carbon atoms, m is an integer of 0 to 3, n is an integer of 1 to 3, and X1 is a hydrogen atom or a fluorine atom, and an anti-ferroelectric liquid crystal compound of the formula (2),  wherein R2 is a linear alkyl group having 6 to 12 carbon atoms, X2 is a hydrogen atom or a fluorine atom, A is —CH3 or —CF3, r is 0 or 1 and C* is an asymmetric carbon, provided that when A is —CH3, r is 0 and p is an integer of 4 to 10, that when A is —CF3 and when r is 0, p is an integer of 6 to 8, and further than when A is —CF3 and when r is 1, q is an integer of 5 to 8 and p is 2 or 4.

Abstract: Provided are novel acetylene compounds which are useful as a component for a liquid crystal composition used for a liquid crystal element, a liquid crystal composition containing said compounds and a liquid crystal element using said liquid crystal composition. The acetylene compound is represented by Formula (1): n-CmH2m+1—C≡C—A—Z1—B—Y1—R1  (1) wherein m represents an integer of 2 to 24; R1 represents a linear or branched alkyl group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or a linear or branched alkenyloxyalkyl group each of which may be substituted with a halogen atom; R1 may have an asymmetric carbon atom, and the asymmetric carbon atom may be optically active; A and B represents a cyclic group such as a phenylene group, a biphenylene group, a naphthylene group and the like each of which may be substituted with a halogen atom.

Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2, in each case independently of one another, are (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by —O— and/or —S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2—O—, —OCH2—, —CH2CH2—, —CH═CH—, —C≡C— or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the proviso that at least one of the radicals A1 and A2 present in the molecule is are suitable as components of liquid-c

Abstract: An electroptical system which between 2 electrode layers contains a PDLC film comprising a liquid crystal mixture forming micro-droplets in an optically isotropic, transparent polymer matrix, in which one of the refractive indices of the liquid crystal mixture is matched to the refractive index of the polymer matrix, which exhibits an electrically switchable transparency essentially independent of the polarization of the incident light, the precursor of the PDLC film of which comprises one or more monomers, oligomers and/or prepolymers and a photoinitiator, and is cured photoradically, the liquid crystal mixture of which comprises one or more compounds of the formula I in which the substituents are defined herein characterized in that the liquid crystal mixture additionally contains one or more reactive liquid crystalline compounds in order to obtain improved switching times especially at low temperatures.

Abstract: Disclosed are (a) liquid crystalline compounds which are essential as component of the liquid crystal compositions, are excellent in miscibility with other liquid crystal compositions, particularly in the miscibility at low temperatures, and expressed by the general formula (1) wherein R0 and R1 independently represent an alkyl group having 1 to 10 carbon atoms; ring A0, ring A1, ring A2, and ring A3 represent 1,4-cyclohexylene group, 1,3-dioxane-2,5-diyl group, 1,4-phenylene group in which one or more hydrogen atoms on the ring may be represented by a halogen atom or R2O group, pyridine-2,5-diyl group, or pyrimidine-2,5-diyl group; Z0, Z1, Z2, and Z3 represent —CH2CH2—, —CH═CH—, —C≡C—, —CH2O—, —OCH2—, —CF2O—, —OCF2—, —COO—, —OCO—, —(CH2)4—, or single bond; Q1 and Q2 represent hydrogen atom or a halogen atom; Q3 represents hydrogen atom, a halogen atom, or R2O g

Abstract: Liquid crystal phases containing components of the formulae I and III have an acceptable combination of threshold steepness, viewing angle and temperature dependence at a low threshold voltage.