To obtain a liquid crystalline polyester which, when aligned, exhibits high selectivity and transmission of polarized light by incorporating a plurality of specific kinds of structural units in a specified ratio into the same and by imparting a specified logarithmic viscosity to the same.
This liquid crystalline polyester contains 10-40 mol% structural units represented by formula I, 10-50 mol%; structural units represented by formula II, 10-40 mol% structural units represented by formula III, 1-40 mol% structural units represented by formula IV, and 0-30 mol% structural units represented by formula V and has a logarithmic viscosity, measured at a concentration of 0.5 g/dl in a phenol/tetrachloroethane (60/40 by wt.) mixed solvent at 30°C, of 0.05-1.0. In the formula, A is e.g. a group represented by formula VI; R is H, CH3, Cl, or the like; D is e.g. a group represented by formula VII; L is a 3-20C optically active divalent aliphatic group containing at least one asymmetric carbon atom; and E is e, g, a group represented by formula VIII, Preferably, the polyester exhibits a cholesteric liquid crystal phase in the molten state and, when cooled to the liquid crystal transition temperature or lower, exhibits a fixable cholesteric alignment in the liquid crystal.
KAMINADE TADAHIRO
NISHIMURA RYO
