ANTHRAQUINONE DERIVATIVES, METHOD FOR PREPARING SAME, LIQUID-CRYSTAL MATERIAL AND ELECTRO-OPTICAL DEVICE

摘要

EASED THEREON The present invention relates to anthraquinono derivatives of the general formula (I): (I) < IMG > wherein A, M, B, Z are the same or different substituents having meanings R1DX, R2EY, wherein R1 and R2 are the same or different and represent each a C4-C1 a alkyl, < IMG > X, Y are the same or different and represent each oxygen or a group NH, NR3; E is an ordinary bond, < IMG > Y + E + R2 = H, Cl, Br, NO2, NR3R4, wherein R3 is a C1-C18 alkyl, R4 is H or C4H9, or R3 + R4 = ? CH2 ?5; n = 0 or1,m , 0, 1, 2, excluding compounds, wherein A = M = B = Z = H, Cl, Br, NO2, NR3R4. These compounds are prepared by acylation of anthraquinone derivatives of the general formula (II): (II) < IMG > whercin W, T, L, K are the same and/or different substituents representing each NH2, NHR3, OH, H, Cl, Br, NO2, NR3R4, wherein: R3 is a C1-C8 alkyl, R4 is hydrogen or C4H9, R3 + R4 = ? CH2 ?5, by means of acid chlorides of the general formula (III): R1DCl (III) wherein R1 and D are as identified in formula (I). The compounds corresponding to the above-given formula (I) are dyestuffs with negative dichroism which are incorported into a composition of a liquid-crystal material. The liquid-crystal material comprises a liquid-crystal matrix and at least one derivative or anthraquinone of the above-given formula (I). This liquid crystal material is used in an electrooptical device as a dichroic working body positioned between optically transparent plates having, on their inner sides, transparent electrodes provided with conductors for connection to a power supply source.