OPTICAL ANISOTROPIC FILM, PROCESS FOR PRODUCING OPTICAL ANISOTROPIC FILM, SUBSTRATE FOR LIQUID CRYSTAL CELL, AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

A novel optically anisotropic film useful for optical compensation of a liquid crystal display device is provided. The optically anisotropic film has a distorted twisted spiral structure, which is formed from a liquid-crystalline composition comprising a liquid-crystalline compound and at least one optically active compound the torsional force of which is changed by light. The optically anisotropic film is produced, for example by (1) heating a liquid-crystalline composition to temperature T 1 ; and (2) irradiating the liquid-crystalline composition with polarized light at temperature T 2 , provided T NI < T 1 < 150°C (XI) and T CN < T 2 < T NI (XII), wherein T NI is the temperature at which the liquid-crystalline composition phase transitions from a cholesteric phase to an isotropic phase, and T CN is the temperature at which the liquid-crystalline composition phase transitions from a crystal phase to a cholesteric phase.