| 摘要 |
PURPOSE: To sufficiently enlarge the wavelength dispersion of birefringence while maintaining the color compensating property and to obtain a color compensator with the wavelength dispersion value freely changeable by laminating a specified liq.-crystal polyester which has been oriented and fixed on a transparent substrate and specifying the value for birefringence. CONSTITUTION: A liq.-crystal polyester which is twisted and nematically oriented in the liq. crystal state, exhibiting a vitreous state below the transition point of the liq. crystal and contg. 3-40mol% 4-hydroxycinnamic acid unit shown by formula I and 15-40mol% catechol unit shown by formula II is oriented, fixed and laminated on a transparent substrate to constitute the compensator for a liq. crystal display element. Meanwhile, the ratio of the value Δn (450nm) of birefringence to the light of wavelength 450nm to the value Δn (600nm) of birefringence to the light of wavelength 600nm is controlled to 1.14-1.30. In the formulas, X and Y are respectively hydrogen atom, Cl, Br or 1-4C alkyl. |
