New methylene-spiro=alkane cpds. and use in liquid crystal media - for electro-optical displays, esp. active matrix or supertwist displays, with low viscosity and moderate positive dielectric anisotropy

摘要

New methylene-spiroalkane derivs. are of formula (I); where X1-2 = H, F, Cl, CF3 or 1-6C alkyl; W = CH2 or CH2CH2; MG = a mesogenic gp.; m = 1, 2 or 3. USE/ADVANTAGE - (I) are used in liquid crystal (LC) media, which are used in electrooptical displays (claimed). They are esp. useful in cells of the TN, STN and SBE, guest-host, deformation aligned phase and dynamic scattering type, esp. in media for active matrix or supertwist displays. (I) are stable, LC or mesogenic cpds. with relatively low viscosity and moderate positive dielectric anisotropy.