Abstract: The invention relates to chiral compounds of formula I, to liquid crystal mixtures comprising at least one chiral compound of formula I, to chiral linear or crosslinked liquid crystal polymers obtainable by polymerizing a polymerizable mixture comprising at least one chiral compound of formula I, to the use of chiral compound of formula I and mixtures and polymers obtained thereof in liquid crystal displays, active and passive optical elements, adhesives, synthetic resins with anisotropic mechanical properties, cosmetic and pharmaceutical compositions, diagnostics, liquid crystal pigments, for decorative and security applications, nonlinear optics, optical information storage or as chiral dopants, and to a liquid crystal display comprising a mixture comprising at least one chiral compound of formula I.

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. The electroptical system comprises a PDLC film comprising a liquid crystal mixture forming micro-droplets in an optically isotropic, transparent polymer matrix between 2 electrode layers. 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: A liquid crystal display device containing a liquid crystal cell and at least one reflective polarizer or a polarizer combination having at least one reflective polarizer as a means to generate circular polarized light. The reflective polarizer includes an optically active layer of an anisotropic polymer material with a helically twisted planar molecular orientation. The material is oriented so that the axis of the molecular helix extends transversely to the layer, and the pitch of the molecular helix is varied in such a manner that the difference between the maximum pitch and the minimum pitch is at least 100 nm.

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. The reactive liquid crystalline compounds are of formula II, R′—G′—R″, wherein R′, G′ and R″ are as defined herein. 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: 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 invention relates to compounds of formula I 1

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. The reactive liquid crystalline compounds are of formula II, R′—G′—R″, wherein R′, G′ and R″ are as defined herein.

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

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

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: 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: A liquid crystal display device containing a liquid crystal cell and at least one reflective polarizer or a polarizer combination having at least one reflective polarizer as a means to generate circular polarized light. The reflective polarizer includes an optically active layer of an anisotropic polymer material with a helically twisted planar molecular orientation. The material is oriented so that the axis of the molecular helix extends transversely to the layer, and the pitch of the molecular helix is varied in such a manner that the difference between the maximum pitch and the minimum pitch is at least 100 nm.

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: The invention relates to 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. The liquid crystal mixture comprises one or more compounds of the formula I ##STR1## wherein Z.sup.1, Z.sup.2, ##STR2## X.sup.1, X.sup.2, Q, Y, n and R are as defined herein. 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: The invention relates to copolymers made from mono-reactive liquid and/or di-reactive liquid crystals which can be photopolymerized to form copolymers and to novel reactive liquid crystal compound having a nematic phase. Preferentially the reactive liquid crystal is polymerized while in the liquid crystal phase to produce an oriented birefringent polymer film. To do this, the reactive liquid crystal, in its nematic or smectic phase is aligned (by well known techniques such as rubbed polyimide, etc.) and the thin film containing a small amount of photoinitiator, is subjected to ultraviolet light whereupon it polymerizes into a thin, aligned polymer film.

Abstract: An electrooptical system is disclosed in which a PDLC film is positioned between 2 electrode layers. The PDLC film contains a liquid crystal mixture forming microdroplets in an optically isotropic, transparent polymer matrix. The liquid crystal mixture comprises one or more compounds of formula I ##STR1## wherein R, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, X.sup.1, X.sup.2, Q, Y and n as herein defined, and one or more reactive liquid crystalline compounds. The PDLC film exhibits improved switching times, especially at low temperatures.

Abstract: An electrooptical system is disclosed in which a PDLC film is positioned between 2 electrode layers. The PDLC film contains a liquid crystal mixture forming microdroplets in an optically isotropic, transparent polymer matrix. The liquid crystal mixture comprises one or more compounds of formula I ##STR1## wherein R, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, X.sup.1, X.sup.2, Q, Y and n are as herein defined, and one or more reactive liquid crystalline compounds. The PDLC film exhibits improved switching times, especially at low temperatures.

Abstract: An electrooptical system is disclosed in which a PDLC film is positioned between 2 electrode layers. The PDLC film contains a liquid crystal mixture forming microdroplets in an optically isotropic, transparent polymer matrix. The liquid crystal mixture comprises one or more compounds of formula I ##STR1## wherein R, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, X.sup.1, X.sup.2, Q, Y and n are as herein defined, and one or more reactive liquid crystalline compounds. The PDLC film exhibits improved switching times, especially at low temperatures.

Abstract: The invention relates to copolymers made from mono-reactive liquid and/or di-reactive liquid crystals which can be photopolymerized to form copolymers and to novel reactive liquid crystal compound having a nematic phase. Preferentially the reactive liquid crystal is polymerized while in the liquid crystal phase to produce an oriented birefringent polymer film. To do this, the reactive liquid crystal, in its nematic or smectic phase is aligned. (by well known techniques such as rubbed polyimide, etc.) and the thin film containing a small amount of photoinitiator, is subjected to ultraviolet light whereupon it polymerizes into a thin, aligned polymer film.